Organophosphate pesticide poisoning: symptoms, emergency action and treatment

Organophosphates are chemicals used mainly as insecticides. MedlinePlus lists organophosphates and carbamates among the stronger insecticides that a farm or commercial greenhouse might use or someone might store in a garage, and notes that the symptoms of organophosphate and carbamate poisoning are the same. The UKHSA review adds that organophosphates are widely used in agriculture and public health programmes, and have also been used as chemical warfare agents.

The NHS lists pesticides and chemicals found in some workplaces among the common causes of poisoning, which it describes as happening when you swallow, touch or breathe in a harmful substance.

MedlinePlus lists the symptoms of organophosphate or carbamate poisoning across the body. Symptoms can begin soon after exposure. The NHS also notes that symptoms of poisoning generally may take a few hours or days to start.

• Heart and breathing: slow heart rate, difficulty breathing and wheezing.

• Nervous system: anxiety, dizziness, headache, weakness, seizures and coma.

• Eyes and face: drooling, increased tears and small pupils.

• Stomach: abdominal cramps, diarrhoea, loss of appetite, nausea and vomiting.

• Bladder: increased urination.

• Skin: blue-coloured lips and fingernails.

The NHS says to call 999 or go to A&E if you think you, a child or someone else may have swallowed, touched or breathed in something harmful, or if someone has lost consciousness, has stopped breathing, has severe difficulty breathing or has a seizure. It advises not to drive yourself to A&E. If you are unsure whether something is harmful, NHS 111 can advise.

While waiting for help, the NHS advises starting CPR if someone is unresponsive and not breathing, using the recovery position if they are unconscious but still breathing, and keeping checking their breathing. Try to find out what caused the poisoning and take the substance or its packaging to show doctors, if possible. Do not try to make someone sick and do not give them anything to eat or drink.

MedlinePlus, a US source, adds that if the chemical is on the skin or in the eyes, you should flush with lots of water for at least 15 minutes, and if the person has breathed it in, move them to fresh air right away. It also advises taking the container to hospital.

The NHS says people with poisoning need hospital treatment, and that treatment depends on what has caused it. It may include antidotes, a charcoal drink for some poisons, treatment for symptoms such as fluids into a vein, and removing the poison from the body. If a person has no symptoms they may not need treatment but may need to be monitored for several hours in case they become unwell.

MedlinePlus describes what to expect in the emergency room for insecticide poisoning: monitoring of vital signs, blood and urine tests, and treatment that may include breathing support with a ventilator, fluids through a vein, and medicine to treat the effects of the poison such as atropine, along with support for blood pressure or heart rate. MedlinePlus says how well someone does depends on how severe the poisoning is and how quickly treatment is received, and that it is a good sign if the person continues to improve in the first 4 to 6 hours after treatment.

The UKHSA review says the clinical features of poisoning are characterised by a triphasic response: an initial acute cholinergic phase, an intermediate syndrome (both associated with high mortality) and a disabling but non-lethal delayed polyneuropathy. It notes the delayed polyneuropathy may occur even without the cholinergic or intermediate phases.

The review also says that the precise health effects following occupational exposures are yet to be completely defined and that better quantification of occupational exposure and appropriate preventive measures are still needed. If you have had a significant exposure and have ongoing symptoms, tell your doctor about the exposure.

The NHS suggests keeping medicines and chemicals out of reach of children, ideally in a locked cupboard, keeping liquid products in their original containers so they are not mistaken for drinks, and wearing equipment such as gloves, goggles or a mask when handling or using harmful chemicals. People who use pesticides at work should follow the product label and their employer's safety instructions.

The UKHSA review concludes that improved assessment of occupational exposure and preventive measures are needed, which is a reminder that protective equipment and correct handling matter even when no obvious accident has happened.

Emergency treatment for poisoning is provided through 999, NHS 111 and hospital emergency departments, with specialist advice available to clinicians. Private care is not a substitute for emergency treatment, which should always be sought immediately.

There is no dedicated NHS patient page for organophosphate poisoning. This guide relies on the NHS poisoning pages for emergency advice, a UK Health Security Agency review article (published in 2004) for the clinical course, and a US MedlinePlus page on insecticide poisoning for symptoms and hospital care. The US source is used because no UK public patient source covering these points was found.