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Management of Poisoning: A handbook for health care workers:
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Part 2: Information on specific poisons
Introduction
This part gives information about the effects of poisoning by specific substances and what to do if you are called on to help someone who might have been poisoned. The substances are in four main groups: pesticides, chemical products used in the home, medicines, and natural poisons including plants and animals.
The information in each section
Some sections cover more than one substance if the first aid for poisoning is more or less the same.
Each section is arranged in the same way so that you can find information quickly. The information you will find under each heading is as follows:
Uses: the common uses for the substance. Abuse is also covered under this heading.
How it causes harm: how a poisonous dose affects the body.
How poisonous it is: whether the substance is likely to cause harm and whether the harm is likely to be severe. It is not possible to give exact indications because the amount that causes severe poisoning may differ greatly for people of different age or weight, or in different circumstances.
Special dangers: any special dangers in the way the chemical is used, the way it looks, or the way it is packed.
Signs and symptoms: the effects of poisoning that you can find out by looking, feeling, and listening, and by talking to the patient. This part does not include information about signs and effects that can only be found out using tests or equipment in hospital.
Information about how to examine the patient and look for these effects is given in Part 1. Part 1 describes the signs and symptoms of liver damage, kidney damage and lung oedema.
The list of signs and symptoms starts with mild effects and ends with severe effects. The larger the dose or the longer the person has been exposed, the more likely you are to see the signs and symptoms further down the list. The list includes the more severe signs and symptoms that might happen if the patient had a very large dose and was not given any first aid or medical treatment.
What to do: the first aid and things that can be done outside hospital by people with basic first aid and nursing skills. Information is also given for primary health care workers who can give injections.
Look back to Part 1 for more information about how to give first aid and how to look after a patient outside hospital.
What to do if there is a delay in getting to hospital: in most cases the patient should go to hospital and should begin the journey at once, but it may take some time to get there. This part tells you what you can do to try to stop severe poisoning if it is going to take more than 3-4 hours to get to hospital.
Before you do anything listed under this heading check that the patient's signs and symptoms are roughly the same as those listed.
Additional information for doctors about clinical effects and treatment is given in boxes. As this book is mainly concerned with treatment that can be given outside hospital it does not give details of hospital treatment. However, some information is given to indicate the kind of treatment, including antidotes or antivenoms, that the patient may need.
Pesticides
Aluminium phosphide and zinc phosphide
Uses
Aluminium phosphide and zinc phosphide are used to preserve grain, especially wheat, and to kill rats. Grain preservative is usually sold as tablets, and rat killer is sold as pellets or bait.
How they cause harm
When damp, phosphides release poisonous phosphine gas. When aluminium phosphide or zinc phosphide is swallowed, poisonous effects are due to phosphine released in the gut. Phosphine affects the gut, liver, kidneys, lungs and heart.
How poisonous they are
Phosphine is very poisonous. People who swallow phosphides or breathe in phosphine may die within a few hours. High concentrations of phosphine in a closed space can kill almost immediately. Low concentrations of phosphine may cause chronic poisoning. As aluminium phosphide or zinc phosphide tablets and pellets give off phosphine when exposed to air, the tablets themselves soon become less poisonous.
Special dangers
In some countries, anyone can buy aluminium phosphide or zinc phosphide rat killers, and many people use these to try to kill themselves. Phosphine poisoning can also happen when:
-people work in the holds of boats carrying cargo treated with phosphides;
-welders use acetylene containing phosphine as an impurity;
-people live or work near grain warehouses where phosphide is used.
Signs and symptoms
From swallowing phosphide or from breathing in phosphide dust or fumes
*Acute poisoning:
- severe vomiting and belly pain,
- chest pain,
- low blood pressure,
- signs of shock: fast weak pulse and cold wet skin,
- unconsciousness,
- signs of lung oedema in 6-24 hours,
- signs of kidney and liver failure within 12-24 hours.
*Chronic poisoning:
- toothache,
- weakness,
- loss of weight and loss of appetite,
- changes to bones causing them to break easily, particularly the jaw bone (phossy jaw).
What to do
If there are poisonous dusts, gases or fumes, move the patient into fresh air. Wear breathing equipment to protect yourself from being poisoned.
Give first aid. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes and keep the patient warm.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed: if the patient is fully awake and breathing normally, and is not vomiting, give activated charcoal and water to drink.
If the patient has signs of kidney failure treat as recommended in chapter nine; if there are signs of liver damage treat as recommended in chapter nine; if there are signs of lung oedema treat as recommended in chapter nine.
Information for doctors outside hospital
As well as the effects listed above, acute poisoning may cause disorders of heart rhythm, and chronic poisoning may cause liver and kidney damage, and anaemia.
Monitor pulse, breathing and blood pressure. Monitor liver and kidney function. Supportive care, including oxygen and mechanical ventilation, should be given as needed:
*Give fluids and electrolytes to replace losses due to vomiting.
*Treat for shock.
There is no antidote. In chronic poisoning, blood cell counts and other blood tests should be done.
Arsenic and arsenic-containing chemicals
Chemicals covered in this section
This section covers arsenic and chemical compounds containing arsenic with other substances, for example:
arsenic trioxide dimethylarsinic acid
arsenic pentoxidelead arsenate
calcium arsenate methylarsonic acid
copper acetoarsenite sodium arsenite
Uses
Chemicals containing arsenic are used:
-in farming and forestry to kill weeds, ants, termites, insects, rats, and mice;
-to protect wood from decay;
-in the microelectronics industry;
-for worming animals;
-in some herbal and traditional remedies: for example, arsenic trioxide is used in herbal medicines; in India chemicals containing arsenic are prescribed by Ayurvedic practitioners; kushtay is an Indian aphrodisiac containing arsenic (these uses are not recommended).
Exposure to arsenic may occur during copper smelting and industrial manufacture of glass, pigments, pesticides, wood preservatives, and silicon chips.
How it causes harm
Arsenic is irritant to skin, lungs and gut. It interferes with life-processes in cells in many parts of the body.
How poisonous it is
Arsenic and chemicals containing arsenic are very poisonous if swallowed, breathed in or in contact with skin. A very small amount can kill. Chronic poisoning can occur from repeatedly swallowing arsenic (for example, by eating contaminated food, or taking traditional remedies containing arsenic) or breathing in dust or fumes. Arsenic can also cause cancer of the skin, lungs or liver a long time after exposure.
Special dangers
People exposed to arsenic fumes or dust are at risk of chronic arsenic poisoning. They should wear protective clothing and may need to use a respirator.
Signs and symptoms
Acute poisoning
*If swallowed
Within 30 minutes, or after several hours if taken with food:
-sudden belly pain and vomiting,
-severe diarrhoea,
-sore throat,
-dry mouth and thirst,
-the breath may smell of garlic,
-signs of shock: weak fast pulse, cold damp skin, low blood pressure and blue skin,
-delirium and sudden unconsciousness,
-fits.
The patient may die within 24 hours. If not, after 24 hours there may be:
-jaundice and signs of liver damage,
-signs of kidney damage,
*If breathed in:
-same effects as when swallowed, but without belly pain, vomiting or diarrhoea.
*On the skin:
-same effects as when breathed in,
-redness, blisters.
*In the eyes:
-severe irritation with pain and redness.
Chronic poisoning
Long-term exposure to small doses over many weeks or years, by swallowing or breathing in, may result in:
- weakness,
- loss of appetite, nausea and vomiting,
- diarrhoea or constipation,
- skin rash,
- thick skin on the palms of the hands or the soles of the feet,
- hoarse voice and sore throat,
- sometimes the patient can taste metal, and the breath and sweat smell of garlic,
- yellow skin as a result of liver damage,
- blood in the urine as a result of kidney damage,
- numbness or pain in the soles of the feet because the nerves have been damaged,
- hair loss,
- white lines on the nails,
- cancer of the skin, lungs or liver.
What to do
Acute poisoning
If there are poisonous dusts, gases or fumes, move the patient into fresh air. Wear breathing equipment to protect yourself from being poisoned.
Give first aid. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes and keep the patient warm.
In the eyes
Wipe the face gently with a cloth or paper to soak up chemical. Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows, or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothing, shoes, socks and jewellery. Do not get any of the chemical on your own skin or clothes or breathe in vapours. Wash the patient's skin, nails and hair thoroughly with soap and cold or lukewarm water, for at least 15 minutes, if possible using running water. If a large area is affected use a shower or a hand-held hose but protect the patient's eyes.
If the patient has a fit, treat as recommended in chapter five.
If the patient is awake, give water to drink, two cupfuls per hour for 12 hours, to replace the water lost in diarrhoea.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed: if it happened less than 4 hours ago, and if the patient is fully awake, breathing normally, and has not had muscle twitching or fits:
*Make the patient vomit, unless he or she has already vomited a lot.
*Give activated charcoal and water to drink. If you have made the patient vomit, wait until vomiting has stopped.
Chronic poisoning
Take the patient to hospital.
Information for doctors outside hospital
Monitor breathing, pulse, blood pressure, fluid and electrolyte balance, and liver and kidney function. Supportive care, including oxygen and ventilation, should be given as needed:
*Fluid and electrolyte balance should be corrected.
*Low blood pressure should be treated with intravenous fluids and the patient kept lying with the feet raised higher than the head.
*For repeated fits diazepam should be given by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
If the patient has symptoms, an antidote should be given as soon as possible. Dimercaprol can be given by deep intramuscular injection.
Dose: Days 1 and 2: 2.5-3 mg/kg of body weight every 4 hours.
Day 3: 3 mg/kg of body weight every 6 hours.
Days 4-10: 3 mg/kg of body weight every 12 hours until symptoms of poisoning are gone.
Side-effects of dimercaprol: pain at the injection site, itchy rash, burning feeling in lips, mouth and throat, fever, headache, low blood pressure or high blood pressure, vomiting, and fits.
Succimer (DMSA; dimercaptosuccinic acid) or DMPS (dimercaptopropane-sulfonate) can be used instead of dimercaprol if available. They are less toxic than dimercaprol and can be given by mouth. Contact a poisons centre for more information.
Chlorophenoxyacetate weedkillers
Chemicals covered in this section
This section covers a group of weedkillers known as chlorophenoxyacetate weedkillers (sometimes shortened to phenoxy or chlorophenoxy weedkillers). The following list gives the commonly used short names and the full chemical names of some of these products:
2,4-D 2,4-dichlorophenoxyacetic acid
MCPA(4-chloro-2-methylphenoxy)acetic acid
mecoprop (MCPP) 2-(2-methyl-4-chlorophenoxy)propionic acid
dichlorprop (DCPP) 2-(2,4-dichlorophenoxy)propionic acid
2,4,5-T 2,4,5-trichlorophenoxyacetic acid
Many products are mixtures of more than one of these weedkillers.
Uses
They are used to kill broad-leaved weeds in cereal crops, grassland, parks and gardens, and weeds in ponds, lakes and irrigation canals.
How they cause harm
They irritate the skin, mouth and gut, cause heat exhaustion, and damage the muscles, nerves and brain. Some liquid products also contain petroleum distillates which may cause lung oedema if swallowed.
How poisonous they are
Most cases of poisoning are a result of people swallowing large amounts of concentrated liquid product. Some deaths have been reported. These chemicals can cause harm if they are breathed in or brought into contact with the skin, but only if people are exposed to very large amounts.
Signs and symptoms
*If swallowed:
-burning pain inside the mouth,
-coughing and choking if the product contains petroleum distillate,
-belly pain, vomiting and diarrhoea,
-fever or low temperature,
-confusion,
-muscle pain, muscle weakness and twitching,
-low blood pressure,
-fast breathing and blue skin,
-unconsciousness,
-fits.
Death may occur within a few hours.
If the patient survives more than a few hours:
-lung oedema within 12-24 hours, if the product contains petroleum distillates,
-dark urine and signs of kidney damage.
-signs of liver damage.
*On the skin:
-redness and irritation.
If large areas of skin are covered:
-muscle pain, muscle weakness and twitching,
-unconsciousness.
*If breathed in (large doses):
-muscle pain, muscle weakness and twitching,
-unconsciousness.
*In the eyes:
-redness and irritation.
What to do
Give first aid. If the patient stops breathing open the airway, wash chemical off the patient's lips, then give mouth-to-mouth or mouth-to-nose respiration. Give heart massage if the heart stops.
If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes.
If the patient has a fit, treat as recommended in chapter five.
If the patient has a fever, wash the body with cool water. If the patient has a low temperature, keep him or her warm.
In the eyes
Wash the eyes with water for at least 15-20 minutes. Check that there are no solid bits of chemical on the lashes or eyebrows, or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothing, shoes, socks and jewellery. Wash the patient's skin thoroughly with soap and cold water for 15 minutes, if possible using running water.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the pesticide was swallowed: if it happened less than 4 hours ago, and if the patient is fully awake, breathing normally, and has not had muscle twitching or fits:
*Make the patient vomit unless he or she has already vomited a lot.
*Give activated charcoal and water to drink. If you have made the patient vomit, wait until vomiting has stopped.
Keep the patient in a quiet place.
Information for doctors outside hospital
As well as the effects listed above, there may be metabolic acidosis, and myoglobin and blood in the urine.
Monitor breathing, pulse, blood pressure, fluid and electrolyte balance. Supportive care, including oxygen and ventilation, should be given as needed:
* Fluid and electrolyte balance should be corrected.
* For repeated fits give diazepam by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
Give sodium bicarbonate, 10-15 g daily, to make the urine alkaline and increase elimination.
Dinitro-o-cresol (DNOC), dinitrophenol, dinoseb and pentachlorophenol
Chemicals covered in this section
This section covers:
*dinitro-o-cresol (DNOC), dinitrophenol and dinoseb (2-sec-butyl 4,6-dinitrophenol);
*pentachlorophenol, also called chlorophen, PCP, and pentachlorphenol;
*sodium pentachlorophenate, also called pentachlorphenate sodium, pentachlorophenoxy sodium, sodium PCP, sodium pentachlorphenate, sodium pentachlorophenolate, and sodium pentachlorophenoxide.
Uses
They are used to kill weeds, insects and fungi, and to preserve wood from rot and decay.
How they cause harm
They speed up chemical processes in the body so that the body overheats, causing heat stroke or heat exhaustion. They also damage the liver and kidney and the nervous system. Liquid products may contain petroleum distillates or methanol.
How poisonous they are
Spray, dust and fumes are poisonous if breathed in or swallowed, or if they come into contact with the skin. Poisoning is worse if the patient is hot.
Special dangers
People may be poisoned by breathing in fumes or spray if pentachlorophenol is used inside buildings where there is too little fresh air. It is dangerous to use these chemicals without wearing protective clothing to cover the body and prevent skin absorption.
Signs and symptoms
*If swallowed
Within a few hours:
-yellow skin, especially on the palms of the hands, and yellow hair, but the whites of the eyes do not turn yellow (dinitro-o- cresol and dinoseb only),
-sweating and thirst,
-nausea and vomiting,
-high fever,
-dehydration,
-tiredness,
-anxiety, restlessness, headache and confusion,
-fast deep breathing,
-fast pulse,
-bright yellow urine (dinitro-o-cresol and dinoseb only),
-the patient passes very little urine, as a result of kidney damage,
-fits,
-unconsciousness,
-lung oedema.
*On the skin:
-rash,
-same effects as when swallowed.
*In the eyes:
-severe irritation, redness and watering.
*If breathed in:
-irritation of the nose and throat,
-shortness of breath and chest pain,
-same effects as when swallowed.
What to do
If there are poisonous sprays, dusts, gases or fumes, move the patient into fresh air. Wear breathing equipment to protect yourself from being poisoned.
Give first aid. If the patient stops breathing open the airway, wash chemical off the patient's lips, then give mouth-to-mouth or mouth-to-nose respiration. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes.
If the patient has a fit, treat as recommended in chapter five.
If the patient is awake, give water to drink, to replace the water lost by sweating.
If the patient has a fever, wash the body with cool water. Do not give aspirin to treat the fever.
Keep the patient lying down and resting.
In the eyes
Dab the face very gently with a cloth or paper to soak up chemical. Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows, or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Wash the skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water. If a large area is affected use a shower or a hand-held hose but protect the patient's eyes. Do not try to remove all the yellow colour - it is in the skin and will not wash off.
Take the patient to hospital at once. Do not let the patient walk, as it will quickly exhaust him or her and make the poisoning worse.
What to do if there is a delay in getting to hospital
Keep the patient lying down in a cool place.
If the chemical was swallowed: if it happened less than 4 hours ago, and if the patient is fully awake, breathing normally, and has not had muscle twitching or fits:
*Give activated charcoal and water to drink.
*Give 2 cupfuls of water every hour for the first 24 hours.
Do not make the patient vomit. The patient may choke on the vomit if he or she becomes unconscious or has a fit.
If the patient has lung oedema, treat as recommended in chapter nine. If the patient has signs of liver damage, treat as recommended in chapter nine. If the patient has signs of kidney damage, treat as recommended in chapter nine.
Information for doctors outside hospital
As well as the effects listed above, there may be metabolic acidosis. Monitor breathing, pulse, blood pressure, rectal temperature, blood glucose, and liver and kidney function. Supportive care, including oxygen and ventilation, should be given as needed:
*Intravenous glucose or frequent meals to make sure the patient has a good supply of energy.
*Fluid and electrolyte balance and acid-base balance should be corrected.
*For repeated fits diazepam should be given by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
Insect repellent
Chemicals covered in this section
Diethyl toluamide, also called N,N-diethyl-3-toluamide or deet.
Uses
Diethyl toluamide is used on the skin as an insect repellent to prevent bites from mosquitos, fleas and biting flies. It has no effect against stinging insects. Products may be in the form of lotions, cream sticks, aerosol sprays or towelettes. The concentration may vary from 5% to 100%.
How it causes harm
It damages the brain. Repeated use on the skin may cause rashes and dermatitis.
How poisonous it is
Severe poisoning does not happen very often. It is usually a result of swallowing a large amount of a highly concentrated product, or putting too much on the skin over a period of several weeks. Poisoning is reported more often in children than adults, and girls seem more likely to be poisoned than boys. Rarely, acute poisoning may cause brain damage in children.
Special dangers
Children have been poisoned by insect repellents that were sprayed on their skin over several weeks, and by sleeping in beds sprayed with deet. Acute poisoning in children may be mistaken for a viral infection.
Signs and symptoms
*If swallowed
From small amounts or products containing a low concentration:
-nausea and vomiting,
-belly pain,
-diarrhoea.
From large amounts of highly concentrated products, within 30 minutes to 6 hours:
-unconsciousness,
-fits,
-signs of liver damage.
Rarely, acute poisoning in children may cause brain damage with:
-slurred speech,
-staggering walk,
-abnormal movements of fingers and toes,
-trembling,
-fits,
-shallow breathing,
-low blood pressure,
-fast pulse.
*In the eyes:
-irritation, which may be severe if the product is concentrated.
*On the skin
If the solution is concentrated (>50% deet):
-a burning feeling,
-blisters and ulcers.
After repeated use:
-redness and rash,
-signs of poisoning if large amounts have been used.
What to do
Give first aid. If the patient stops breathing open the airway and give mouth-to-mouth or mouth-to-nose respiration. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position, check breathing every 10 minutes and keep the patient warm.
If the patient has a fit, treat as recommended in chapter five.
In the eyes
Wash the eyes for at least 15-20 minutes with running water.
On the skin
If skin contact is greater than for normal use of insect repellent, immediately remove contaminated clothing. Wash skin, nails and hair thoroughly with soap and cold or lukewarm water, for at least 15 minutes, if possible using running water.
Patients who have signs and symptoms showing that a large amount might have been swallowed, or who have severe irritation of skin or eyes, should go to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed: if a large amount was swallowed less than 4 hours ago, and if the patient is fully awake, breathing normally, and has not had fits:
*Make the patient vomit unless he or she has already vomited a lot.
*Give activated charcoal and water to drink. If you have made the patient vomit, wait until vomiting has stopped. Give sodium sulfate or magnesium sulfate with the charcoal.
If the patient has signs of liver damage, treat as recommended in chapter nine.
Information for doctors outside hospital
Rarely, children may develop a toxic encephalopathy. This may be mistaken for viral encephalitis or epilepsy.
In severe poisoning, monitor breathing, heart, blood pressure, fluids and electrolytes. Supportive care, including oxygen and ventilation, should be given as needed:
*Low blood pressure should be treated with intravenous fluids.
*For fits, increased muscle tone, opisthotonus or tremors, diazepam or phenobarbital should be given.
Dose of diazepam by intravenous injection:
Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
Metaldehyde
Uses
Metaldehyde is used to kill snails and slugs, and as solid fuel. Slug and snail killers may be in the form of small pellets containing metaldehyde and bran, or may be a liquid that needs to be diluted before use. Solid fuel is made in the form of tablets.
How it causes harm
Metaldehyde affects the gut, the brain, the liver and the kidneys.
How poisonous it is
Metaldehyde is poisonous if swallowed. The pellets used for killing slugs and snails usually contain very little metaldehyde (less than 5%) and do not usually cause severe poisoning. Metaldehyde liquid and solid fuel tablets contain a higher concentration and can cause severe poisoning and possibly death.
Special dangers
Metaldehyde pellets are often sold in packs that are easy for children to open. The pellets are put on top of the soil and children may pick them up.
Signs and symptoms
*If swallowed
Effects are usually seen within three hours, but may be delayed for up to 48 hours:
-nausea, vomiting and belly pain,
-wet mouth,
-flushed face,
-fever,
-drowsiness,
-fast pulse,
-trembling,
-muscle twitching and fits,
-unconsciousness.
After 2-3 days:
-jaundice and signs of liver damage,
-the patient passes very little urine showing that the kidneys are damaged.
What to do
If the patient has swallowed only one or two pellets of slug bait containing less than 5% metaldehyde, there is no need to do anything. If the patient has swallowed more than this, proceed as follows.
Give first aid. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes and keep the patient warm.
If the patient has a fit, treat as recommended in chapter five.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed less than 4 hours ago, and if the patient is fully awake and breathing normally, and has not had muscle twitching or fits:
*Make the patient vomit, unless he or she has already vomited a lot.
*Give activated charcoal and water to drink. If you have made the patient vomit, wait until he or she has stopped vomiting.
If the patient has signs of liver damage, treat as recommended in chapter nine. If the patient has signs of kidney damage, treat as recommended in chapter nine.
Information for doctors outside hospital
Monitor pulse, breathing, blood pressure and liver function. Supportive care, including oxygen and ventilation, should be given as needed. For repeated fits diazepam should be given by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
Organochlorine pesticides
Pesticides covered in this section
There are many organochlorine pesticides. Some of the more well known ones are aldrin, chlordane, DDT, dieldrin, endosulfan, endrin, and lindane (also known as gamma benzene hexachloride or gamma-HCH).
Uses
Organochlorine pesticides are widely used in agriculture, and to control disease-carrying insects such as malaria mosquitos. Lindane is also used to kill fleas, head lice, snails and slugs, and is sprayed on seeds to stop insects eating them.
Products may be dusts, wettable powders, pellets or liquids. Some products are burnt to make smoke that kills insects. Products for killing head lice are made as lotions or shampoos.
How they cause harm
They affect the brain and breathing. Liquid products may also contain solvents such as petroleum distillates which may cause lung oedema if swallowed.
How poisonous they are
Organochlorine pesticides are poisonous if they are swallowed, breathed in, or brought into contact with the skin. The poisonous amount varies a lot between individual pesticides. Aldrin, dieldrin, endrin and endosulfan are more poisonous than chlordane, DDT and lindane.
Special dangers
People may be poisoned if they do not wash after using the pesticide, or if they go into houses that are being sprayed. Lindane shampoo can cause poisoning in young children if too much is used or if it is used too often. People have been poisoned by eating food contaminated with these chemicals.
Signs and symptoms
Effects usually begin after 1-6 hours. Poisoning with DDT may be delayed for up to 48 hours.
*If swallowed:
-vomiting, diarrhoea and belly pain,
-anxiety, excitement and weakness,
-headache and dizziness,
-shaking and trembling,
-fits,
-unconsciousness,
-fast breathing, blue skin and signs of lung oedema, if the product contains petroleum distillates.
*If breathed in:
-burning of the eyes, nose or throat,
-anxiety, excitement and weakness,
-headache and dizziness,
-shaking and trembling,
-fits,
-unconsciousness.
*In the eyes:
-irritation may occur.
* On the skin:
- irritation and rash may occur,
- same effects as if breathed in.
What to do
If there are poisonous dusts, gases or fumes, move the patient into fresh air. Wear breathing equipment to protect yourself from being poisoned.
Give first aid. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes, and keep the patient warm.
If the patient has a fit, treat as recommended in chapter five.
If the chemical has been swallowed do not give milk to drink, or anything fatty or oily by mouth.
In the eyes
Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows, or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Wash the skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed: if it happened less than 4 hours ago, and if the patient is fully awake, breathing normally, and has not had fits:
*Make the patient vomit, unless he or she has already vomited a lot.
*Give activated charcoal and water to drink. If you have made the patient vomit, wait until vomiting has stopped. Give sodium sulfate or magnesium sulfate with the charcoal.
If the patient has signs of lung oedema, treat as recommended in chapter nine.
Information for doctors outside hospital
These chemicals affect respiratory control, muscle activity and heart rhythm. Monitor pulse, breathing and blood pressure. Supportive care, including oxygen and ventilation, should be given as needed. For repeated fits diazepam should be given by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
There is no antidote. Dialysis, haemoperfusion, and diuresis are not useful.
Organophosphorus and carbamate insecticides
Insecticides covered in this section
This section covers organophosphorus and carbamate insecticides. Some are listed below.
Organophosphorus insecticides:
azinphos-methyl fenthion
bromophos-ethyl formothion
bromophosheptenophos
carbophenothion jodfenphos (iodofenphos)
chlorfenvinphos malathion
cythioatemevinphos
demeton-S-methyl parathion-methyl
diazinon phorate
dichlorvos phosmet
dimethoate phoxim
fenitrothion pirimiphos methyl
Carbamate insecticides:
aldicarb methiocarb
bendiocarb methomyl
carbaryl pirimicarb
carbofuran propoxur
These insecticides may be in the form of dusts, granules or liquids. Some products need to be diluted with water before use, and some are burnt to make smoke that kills insects.
Uses
They are widely used in agriculture and in the home to kill insect pests. They are also used to kill malaria mosquitos and insect parasites living on humans or domestic animals.
How they cause harm
They poison the nerves that control glands, muscles, breathing and the brain. Although the clinical effects of the two groups are the same, organophosphorus insecticides do not affect the body in exactly the same way as carbamate insecticides, and there are some differences in the antidotes used to treat poisoning. Some products contain petroleum distillates, toluene or xylene, which may cause lung oedema.
How poisonous they are
They may cause serious poisoning and death if they are breathed in or swallowed, or come into contact with the skin or eyes. They differ widely from one another in the amount that causes poisoning. Serious poisoning may occur at lower doses in people who are re- exposed within a few weeks or months.
Carbamate insecticides cause less severe poisoning than organophosphorus insecticides.
Signs and symptoms
Effects may occur very quickly or be delayed for up to 12 hours.
*If swallowed, breathed in, or on the skin:
-confusion, weakness and exhaustion,
-headache,
-nausea, vomiting, belly pains and diarrhoea,
-cold sweating, wet mouth,
-tightness in the chest,
-twitching eyelids and tongue, later twitching over the rest of the body,
-irregular or shallow breathing,
-slow pulse,
-small pupils,
-fits,
-unconsciousness,
-lung oedema,
-incontinence.
*In the eyes:
-irritation, watering and blurred vision,
-same effects as if swallowed or breathed in.
What to do
If there are poisonous dusts, gases or fumes, move the patient into fresh air. Wear breathing equipment and protective clothing to protect yourself from being poisoned.
Give first aid. If the patient stops breathing open the airway, wash chemical off the patient's lips then give mouth-to-mouth or mouth-to-nose respiration. Give heart massage if the heart stops.
If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes, and keep the patient warm.
If the patient has a fit, treat as recommended in chapter five.
In the eyes
Dab the face very gently with a cloth or paper to soak up chemical. Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Be careful not to get any of the chemical on your own skin or clothes, or to breathe in vapours.
Wash the patient's skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water. If a large area is affected use a shower or a hand-held hose, but protect the patient's eyes.
Make the patient lie down and rest. The poisoning may get worse if the patient moves around.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting the patient to hospital
If the chemical was swallowed: if it happened less than 4 hours ago, and if the patient is fully awake, breathing normally, has not had muscle twitching or fits, and is not vomiting, give activated charcoal and water to drink.
If the patient has signs of lung oedema, treat as recommended in chapter nine.
After the patient has recovered
The body chemistry may take weeks or months to recover, even though the patient seems well again. A person who is re-exposed before the body has properly recovered from the first exposure may be very seriously poisoned by a dose that would not normally cause harm. People who have been poisoned with organophosphorus pesticides should not work with them again until they have been examined by a doctor who understands this problem.
Information for doctors outside hospital
As well as the effects listed above, there may be weakness of the muscles used in breathing, bronchospasm, and accumulation of fluid in the air passages and lungs.
Monitor pulse, breathing, blood pressure and fluid loss. Supportive care, including oxygen and ventilation, should be given as needed:
*Secretions should be cleared from the airway.
*Fluid and electrolyte balance should be corrected.
*Diazepam can be given by intravenous injection to relieve anxiety and control fits.
Dose: Adults: 10-20 mg repeated as needed.
Children: 0.25-0.4 mg/kg of body weight repeated to a maximum dose of 5 mg in children aged 1 month to 5 years, and to a maximum dose of 10 mg in children aged more than 5 years.
Antidotes should be given if there are signs of poisoning. Organophosphorus and carbamate insecticides act in slightly different ways, so pralidoxime, which is used to treat organophosphorus insecticide poisoning is not used to treat poisoning by carbamate insecticides.
For both organophosphorus and carbamate insecticides
Give atropine immediately by intravenous injection, until the patient's mouth becomes dry, the heart rate is more than 100 beats per minute, and the pupils are dilated.
Dose: Adults: give a first dose of 2-4 mg. If the patient's mouth is still wet repeat this dose every 10 minutes until the mouth is dry.
Children: give 0.05 mg/kg of body weight repeated every 10 minutes until the mouth is dry.
Keep watching the patient. Repeat the dose as needed to correct wheezing and excess salivation. Patients may die if they are not given enough atropine. Large amounts may be needed for several days.
For organophosphorus (but not carbamate) insecticides
In severe cases and in cases that do not respond to atropine, give pralidoxime mesilate (P-2-S) or chloride (PAM2) in addition to atropine, to reactivate the enzyme inhibited by the insecticide. It may be given at the same time as atropine.
Dose: 30 mg per kg of body weight by slow intravenous injection over 5-30 minutes every 4-6 hours. It can be given intramuscularly if an intravenous dose cannot be given. Obidoxime chloride can be used if pralidoxime is not available.
Paraquat
Use
Paraquat is used as a weedkiller. It is usually sold as a liquid, containing a 20% concentration of paraquat, which must be diluted before use. In some countries a granular solid product is also available for domestic garden use. This contains 2.5% paraquat and 2.5% diquat, and is mixed with water before use.
How it causes harm
Paraquat damages the lungs, liver and kidneys. The 20% solution is corrosive.
How poisonous it is
Paraquat is very poisonous if swallowed. One mouthful of the 20% liquid may result in death from lung damage within 1-4 weeks. Larger amounts may cause death within 12 hours.
Skin contact is unlikely to cause poisoning, unless contaminated clothes are worn for several hours, or a large amount of concentrated paraquat is in contact with damaged skin, or the patient is a child. Breathing in paraquat spray may irritate the nose and throat but is unlikely to cause poisoning.
Special dangers
Many poisonings have happened by accident when paraquat has been stored in bottles that previously held beer, wine or soft drinks. This is a dangerous way to store any poison, as other people may drink from the bottles by mistake, but it may be quite common in places where liquid paraquat is supplied only in large containers. People with small farms or gardens, who only want to buy small amounts, may take a small amount from the large container and put it into other containers. Pesticide sprayers can be severely poisoned if they swallow paraquat while trying to clear blocked spray pipes. Wearing clothes contaminated with liquid paraquat for several hours may result in absorption of a poisonous amount.
Signs and symptoms
*If swallowed:
-vomiting and belly pain,
-diarrhoea, often bloody.
After ingestion of large amounts, severe effects occur within a few hours:
-drowsiness, weakness, giddiness and headache,
-fever,
-unconsciousness,
-cough and irregular breathing,
-lung oedema within a few hours.
The patient may die within 12 hours.
After ingestion of smaller amounts, severe effects develop after 24-48 hours:
-sore mouth and throat after 24-48 hours,
-in some cases there are white ulcers in the mouth and throat, the lining of the mouth and throat peels off, there is pain on swallowing, and the mouth is wet because the patient cannot swallow saliva,
-shortness of breath as lung disease develops,
-in some cases the patient passes very little urine, showing that the kidneys are damaged,
-in some cases, jaundice and signs of liver damage develop.
Death may occur after 2-4 weeks from lung disease.
*On the skin
Contact with the 20% paraquat solution may cause inflammation and blisters; nails may crack and fall off.
Large amounts in contact with damaged skin for many hours may result in:
-shortness of breath as a result of lung disease,
-in some cases the patient passes very little urine, showing that the kidneys are damaged,
-in some cases, jaundice and signs of liver damage develop.
The patient may die from lung disease.
*In the eyes:
-severe inflammation from the 20% paraquat solution, but the eyes recover completely if properly treated.
*If breathed in
Spray or dust may make the nose bleed.
What to do
Give first aid. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes and keep the patient warm.
If swallowed
Do not give anything by mouth if the patient has bad ulcers inside the mouth, because the patient will probably not be able to swallow.
For severe pain in the mouth, give mouthwashes or use local anaesthetic sprays. If the patient can swallow give ice-cold water or ice cream.
If the chemical was swallowed less than 4 hours ago, and if the patient is fully awake, is not vomiting and can swallow, give activated charcoal and water to drink. Give sodium sulfate or magnesium sulfate with the charcoal.
In the eyes
Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows, or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Be careful not to get any of the chemical on your own skin or clothes. Wash the patient's skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water.
Take the patient to hospital as quickly as possible.
What to do if there is a delay getting the patient to hospital
If the chemical was swallowed, and if the patient is fully awake, breathing normally, and can swallow, give two cupfuls of water to drink every hour.
If the patient has signs of lung oedema, treat as recommended in chapter nine.
Information for doctors outside hospital
Supportive care should be given as needed:
- intravenous fluids,
- morphine for pain.
Oxygen may make lung damage worse, so do not give it unless the patient is distressed. Patients who are unlikely to recover can be given oxygen if it makes them more comfortable.
There is no successful treatment for moderate or severe paraquat poisoning.
Phenol and related substances
Chemicals covered in this section
This section covers phenol (also called carbolic acid), creosote (also called wood tar or coal tar), and cresol.
Uses
Phenol and cresol are used as disinfectants and antiseptics. Creosote is used as a wood preservative.
How they cause harm
These chemicals are corrosive but do not cause such bad burns as strong acids or alkalis. They affect the heart, the brain, breathing, the liver and the kidneys.
How poisonous they are
They are poisonous if swallowed or breathed in or absorbed through the skin. Exposure to large amounts may cause death.
Signs and symptoms
*If swallowed:
-burns round mouth and inside mouth and throat,
-vomiting and diarrhoea,
-fast breathing at first,
-weak fast pulse,
-low blood pressure,
-unconsciousness,
-fits,
-signs of kidney failure: the patient passes very little urine and the urine is dark,
-signs of liver damage,
-lung oedema.
The effects on heart and breathing may cause death.
*If breathed in:
-same effects as if swallowed, but without burning in the mouth and throat, vomiting or diarrhoea.
*In the eyes:
-severe pain, redness and watering,
-blindness.
*On the skin:
-chemical burns, which are usually painless,
-skin looks white and wrinkled (with cresol, skin looks red),
-same effects as if swallowed, but without burning in the mouth and throat, vomiting or diarrhoea.
What to do
Give first aid. If the patient stops breathing open the airway, wash chemical off the patient's lips then give mouth-to-mouth or mouth-to-nose respiration. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes, and keep the patient warm.
If the patient has a fit, treat as recommended in chapter five.
In the eyes
Dab the face very gently with a cloth or paper to soak up chemical. Wash the eyes for at least 15-20 minutes with water.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Be careful not to get any of the chemical on your own skin or clothes. Wash the patient's skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water. If a large area is affected use a shower or a hand-held hose but protect the patient's eyes.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed less than 4 hours ago, and if the patient is fully awake and is not having fits, give activated charcoal and water to drink. Do not make the patient vomit.
If the patient has signs of lung oedema treat as recommended in chapter nine. If the patient has signs of kidney failure, treat as recommended in chapter nine.
Information for doctors outside hospital
As well as the effects listed above, these chemicals may cause corrosive injury to the gut, metabolic acidosis, heart rhythm disturbances, and methaemoglobinaemia.
Monitor breathing, pulse and blood pressure. Supportive care, including oxygen and ventilation, should be given as needed:
*Low blood pressure should be treated with intravenous fluids.
*For repeated fits diazepam should be given by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
There is no antidote.
Pyrethrins and pyrethroid insecticides
Chemicals covered in this section
Pyrethrins are natural insecticides extracted from chrysanthemum plants; pyrethroids are manufactured insecticides with similar chemical structures.
Pyrethrum and piperonyl butoxide are pyrethrins. The following chemicals are pyrethroids: bioresmethrin, cypermethrin, deltamethrin, fenvalerate, permethrin and resmethrin.
Uses
These chemicals are used in household insecticide sprays and some mosquito coils and mats. They are also used to control insect pests in places where food such as grain and flour is stored, and in agriculture, on vegetables, fruit trees and shrubs. They are sold as liquids, sprays, dusts and powders.
How they cause harm
They are irritant to the lungs and may affect the brain.
How poisonous they are
Pyrethrin and pyrethroid insecticides are not very poisonous to humans if swallowed, spilt on the skin or breathed in. They sometimes cause allergic reactions. Severe poisoning happens rarely, if a large amount of concentrated product is swallowed.
Signs and symptoms
*If swallowed:
-nausea and vomiting,
-rarely, fits may occur after a very large dose.
*On the skin:
-irritation,
-skin rash and blistering.
*If breathed in:
-runny nose and sore throat,
-some people may get wheezing, sneezing, and shortness of breath.
*In the eyes:
-some may cause severe irritation.
*Allergic reactions:
-shock: pale skin, sweating, fast weak pulse,
-wheezing and shortness of breath.
What to do
If the patient has an allergic reaction
Give first aid. If breathing stops, open the airway and give mouth-to-mouth respiration. Give heart massage if the heart stops.
Put the patient flat on his or her back, with the head turned to one side, and the legs raised higher than the head (by resting the feet on a box, for example). This will help the blood to reach the brain and lessen the danger of vomit blocking the airway.
A patient with an allergic reaction should go to hospital as soon as possible.
If the patient has a fit, treat as recommended in chapter five.
In the eyes
Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows, or in the folds of skin round the eyes. If there is severe irritation take the patient to hospital.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Be careful not to get any of the chemical on your own skin or clothes. Wash the patient's skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water.
Information for doctors outside hospital
If the patient has a severe allergic (anaphylactic) reaction
Give oxygen by face-mask in as high a concentration as possible. Insert an airway if the patient is unconscious.
Give epinephrine (adrenaline), 1 in 1000 (1 mg/ml) as soon as possible by intramuscular injection, unless there is a strong central pulse and the general condition is good. Any delay may be fatal.
Dose:
Age Volume of epinephrine, 1 in 1000
<1 year 0.05 ml
1 year 0.1 ml
2 years 0.2 ml
3-4 years 0.3 ml
5 years 0.4 ml
6-12 years 0.5 ml
Adults 0.5-1 ml
These doses may be repeated every 10 minutes until blood pressure and pulse improve. Doses should be reduced for underweight children.
It is useful to give antihistamines such as chlorphenamine or promethazine, by slow intravenous injection, after the epinephrine, to treat skin rash, itching or swelling and prevent relapse.
If the patient does not get better, supportive care should be given as needed:
-oxygen and ventilation,
-intravenous fluids,
-inhaled salbutamol or intravenous theophylline may be useful for asthma or wheezing.
Rat poisons
Many different chemicals can be used to kill rats, mice and other small rodents:
-aluminium phosphide,
-arsenic,
-strychnine,
-thallium,
-warfarin and other chemicals that have the same effect (brodifacoum, bromadiolone, chlorophacinone, coumafuryl, difenacoum).
Sodium chlorate
Uses
Sodium chlorate is used as a weedkiller, in match heads and in fireworks. It has sometimes been used in mouthwashes, but this is not recommended.
How it causes harm
It stops blood carrying oxygen and damages the liver and kidneys. It also irritates the skin and eyes.
How poisonous it is
It is poisonous if swallowed. People have died after swallowing 2-3 teaspoonfuls.
Special dangers
It looks like white crystals and may be mistaken for sugar or salt if it is put in a food container, or kept in a place where food is normally kept.
Signs and symptoms
*If swallowed:
-nausea, vomiting, diarrhoea and belly pain,
-shallow breathing,
-unconsciousness,
-fits,
-the skin and the inside of the lower eyelids turn a blue colour,
-the patient stops passing urine and has signs of kidney damage
-death may occur within a few hours.
*On the skin:
-irritation,
-redness,
-ulcers and burns.
*In the eyes:
-irritation,
-redness of the eyelids,
-ulcers and burns.
What to do
Give first aid. If the patient stops breathing open the airway, wash chemical off the patient's lips, then give mouth-to-mouth or mouth-to-nose respiration. If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes, and keep the patient warm.
If the patient has a fit, treat as recommended in chapter five.
In the eyes
Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Wash the skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water.
Patients who have swallowed the chemical, or who have burns in the eyes or on the skin, should go to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed less than 4 hours ago and if the patient is fully awake and breathing normally, has not had muscle twitching or fits, and is not already vomiting, make the patient vomit.
If the patient has signs of kidney damage, treat as recommended in chapter nine.
Information for doctors outside hospital
As well as the effects listed above, there may be blood disorders including methaemoglobinaemia and intravascular haemolysis, high serum potassium concentration, and protein and haemoglobin in the urine.
Monitor pulse, breathing and blood pressure. Supportive care, including oxygen and ventilation, should be given as needed:
*Fluid and electrolyte balance should be corrected.
*For repeated fits diazepam should be given by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
There are two chemicals that have been used as antidotes. It may be useful to give one of these.
1. Sodium thiosulfate. This is said to work by changing chlorate into chloride, which is less poisonous, but there is some doubt about how useful it is.
Dose: 2-5 g of sodium thiosulfate in 200 ml of 5% sodium bicarbonate given as a drink.
2. Ascorbic acid. This is said to change methaemoglobin back to haemoglobin, but it works very slowly.
Dose: 1 g every 4 hours given as a drink, or by slow intravenous injection.
In severe poisoning the most useful treatment is exchange transfusion together with haemodialysis.
Strychnine
Strychnine is made from the seeds of the tree called Strychnos nux-vomica.
Uses
Strychnine is used to kill rats, mice, and other animals. It used to be used in medicines such as tonics and laxatives but this is not recommended. In India, kuchlla, a product for killing dogs, contains strychnine.
How it causes harm
If affects the nerves that control the muscles.
How poisonous it is
Strychnine is extremely poisonous if swallowed and works very quickly. Quite small amounts can cause death, but some patients recover if treated in hospital. It does not pass through the skin.
Special dangers
Most cases of poisoning happen when people try to kill themselves. Accidental poisoning is unusual.
Signs and symptoms
*If swallowed
After about 15 minutes:
-numbness and stiffness of face and neck,
-fear,
-muscle twitching,
-painful fits and muscle spasms lasting 1-2 minutes, occurring every 5-10 minutes; the arms and legs are stretched out and the body is arched so that it is supported only by the head and feet,
-the eyes bulge,
-the patient is usually fully awake,
-breathing is difficult and may stop when the patient is having a fit; the skin is blue,
-high temperature,
-signs of kidney damage.
What to do
Give first aid. If the patient stops breathing open the airway, wash chemical off the patient's lips then give mouth-to-mouth or mouth-to-nose respiration.
If the patient is unconscious or drowsy, lay him or her on one side in the recovery position. Check breathing every 10 minutes and keep the patient warm.
Keep the patient as quiet and still as possible, because movement may set off fits.
If the patient has a fit, treat as recommended in chapter five.
Take the patient to hospital as quickly as possible.
What to do if there is a delay in getting to hospital
Keep the patient in a quiet, dark room.
Do not make the patient vomit because vomiting may set off fits.
If the patient has no signs or symptoms, give activated charcoal and water to drink.
Information for doctors outside hospital
Repeated fits may cause high temperature, rhabdomyolysis (muscle breakdown) and kidney failure.
Supportive care should be given as needed:
*Oxygen and ventilation may be needed during fits.
*For repeated fits diazepam should be given by intravenous injection; if this fails the patient may need to be paralysed and ventilated.
Dose of diazepam:
Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
Thallium
Uses
Thallium salts are used to kill rats, mice and other rodents, and ants, but in many countries they are banned from being sold as a pesticide. They have been used as a cream for removing body hair but this is not recommended. They are widely used in industry.
How it causes harm
Thallium affects the gut, nerves, skin and hair.
How poisonous it is
Thallium salts are very poisonous if they are swallowed or brought into contact with the skin. Exposure to small amounts over many weeks, by swallowing, skin contact or breathing in metal fumes, can cause chronic poisoning.
Special dangers
Thallium rat bait made with grain, biscuit crumbs or honey may be mistaken for food. Industrial workers may get chronic poisoning from breathing in fumes or dust, or from handling chemicals without wearing gloves.
Signs and symptoms
Acute poisoning
*If swallowed
Effects appear slowly over 2-3 days:
-belly pain, nausea, vomiting and constipation,
-pain or numbness in the fingers and toes,
-tiredness,
-fits.
After about 7 days:
-pain or numbness in the soles of the feet so that the patient cannot stand or move,
-dizziness,
-drooping eyelids,
-fever,
-jumbled speech and confused behaviour,
-trembling, strange movements of the arms and legs,
-signs of kidney damage.
After 10-14 days:
-hair starts falling out.
Death may occur up to five weeks after swallowing thallium.
Chronic poisoning (from swallowing, skin exposure or breathing in fumes):
-hair falls out leaving bald patches,
-wet mouth,
-blue line on the gums,
-nausea, vomiting, belly pain and constipation,
-pain or numbness in the arms and legs.
What to do
Give first aid. If the patient has a fit, treat as recommended in chapter five.
In the eyes
Wash the eyes for at least 15-20 minutes with water. Check that there are no solid bits of chemical on the lashes or eyebrows, or in the folds of skin round the eyes.
On the skin
Immediately remove contaminated clothes, shoes, socks and jewellery. Wash the skin, nails and hair thoroughly with soap and cold or lukewarm water for at least 15 minutes, if possible using running water.
Take the patient to hospital.
What to do if there is a delay in getting to hospital
If the chemical was swallowed less than 4 hours ago, and if the patient is fully awake and breathing normally, and has not had muscle twitching or fits:
*Make the patient vomit unless the patient has already vomited a lot.
*Give activated charcoal and water to drink. If you have made the patient vomit, wait until vomiting has stopped.
Information for doctors outside hospital
Monitor breathing, blood pressure, pulse, and liver and kidney function. Supportive care, including oxygen and ventilation, should be given as needed. For repeated fits diazepam should be given by intravenous injection.
Dose: Adults: 10-20 mg at a rate of 0.5 ml (2.5 mg) per 30 seconds, repeated if necessary after 30-60 minutes; this may be followed by intravenous infusion to a maximum of 3 mg/kg of body weight over 24 hours.
Children: 200-300 µg/kg of body weight.
The antidote is potassium ferricyanoferrate (Prussian blue). If potassium ferricyanoferrate is not available, ferric ferrocyanide can be used instead. Contact a poisons centre to find out if the antidote is available.
Dose: 250 mg/kg of body weight per day divided into four doses, by mouth or through a stomach tube, until the concentration of thallium in the urine is less than 0.5 µg over a 24-hour-period. The antidote may cause constipation so give a mild purgative (e.g. 50 ml of 15% sorbitol) with each dose.
Haemodialysis should be carried out if there is kidney failure.
Warfarin and other pesticides that stop blood clotting
Chemicals covered in this section
This section covers coumafuryl, warfarin and the "superwarfarins" (brodifacoum, bromadiolone, chlorophacinone and difenacoum).
Uses
These chemicals are used to kill rats and mice. The chemicals are usually mixed with corn, or made into pellets to make a bait that is often coloured blue or green so that people can see it is not food. Warfarin is also used as a medicine to stop blood clotting.
For information on other chemicals sometimes used to kill rats and mice see Part Two (Rat poisons).
How they cause harm
These chemicals stop the blood clotting. This can lead to bleeding inside the body.
How poisonous they are
Warfarin, coumafuryl: swallowing a small amount is unlikely to have an effect. Repeated doses taken over several days or weeks may cause serious poisoning or even death. Doctors who prescribe long-term treatment with warfarin medicine should check the patient's blood clotting.
Brodifacoum, bromadiolone, chlorophacinone and difenacoum: swallowing one dose may cause signs of poisoning, and the effects of poisoning may be severe and last for some time.
Special dangers
Rat poisons are often put on the ground in open dishes where they are easily found by children.
Signs and symptoms
*If swallowed
After 12-48 hours, any of these may occur:
-bleeding from cuts takes longer to clot than usual,
-bruising and skin rashes,
-blood in urine,
-patient coughs up blood,
-blood in the stools showing that there is bleeding inside the gut,
-back or belly pain.
For warfarin and coumafuryl: the effects last 3-4 days.
For brodifacoum, difenacoum, bromadiolone and chlorophacinone: the effects may last for weeks or months.
What to do
If the patient has swallowed just a few mouthfuls of rat bait containing warfarin or coumafuryl, there is no need to do anything. If you think the patient may have taken more than this, or if you do not know what the rat poison contains, take the patient to hospital as soon as possible.
What to do if there is a delay in getting to hospital
If the chemical was swallowed less than 4 hours ago and the patient is fully awake and breathing normally:
*Make the patient vomit. If the patient has been taking warfarin as a medicine, do not make the patient vomit, because this may cause bleeding in the gut.
*Give activated charcoal with water to drink. If you have made the patient vomit, wait until vomiting has stopped.
Information for doctors outside hospital
To stop active bleeding quickly, transfusions of either whole blood or fresh frozen plasma should be given. Blood clotting time or prothrombin time and full blood count should be monitored if possible.
Brodifacoum, difenacoum, bromadiolone and chlorophacinone: even if there are no signs or symptoms, or if poisoning is mild, prothrombin time ratios should be measured after 24, 48 and 72 hours.
The antidote is phytomenadione (vitamin K1). This brings the prothrombin time back to normal again and stops bleeding. It should restore the prothrombin time to normal within 12-36 hours, but regular daily doses may be needed for several weeks depending on which chemical was taken in overdose.
Dose: For severe poisoning: a slow intravenous infusion of phytomenadione in 9 g/l (0.9%) sodium chloride solution or glucose. Adults: 100-200 mg per day may be needed for several days or weeks. Doses can be given every 6-8 hours. Prothrombin times should be tested frequently until they are normal; this may take weeks or months in severe cases.
If blood clotting time or prothrombin time is longer than normal, but effects are not severe, give phytomenadione by intramuscular injection.
Dose: adults: 5-10 mg; children: 1-5 mg.
Management of Poisoning: A handbook for health care workers:
1,2,3,4,5,6,7
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