Anticoagulant rodenticide (rat poison) poisoning: signs and what to do

Rodenticide means rodent killer. MedlinePlus describes anticoagulant rodenticides as poisons used to kill rats, and says the ingredients include brodifacoum, bromadiolone, difenacoum, difethialone, chlorophacinone, diphacinone and warfarin, among others, noting that its list may not be all-inclusive.

The harm comes from what they do to blood clotting. An anticoagulant is a blood thinner, as MedlinePlus puts it, and the symptoms it lists are all forms of bleeding or its effects. MedlinePlus lists vitamin K among the treatments given to reverse the effect of the poison.

The NHS says poisoning can happen if you swallow, touch or breathe in substances that can be harmful. It lists pesticides among common substances that can cause poisoning, alongside medicines, household cleaning products, alcohol and drugs, certain plants and mushrooms, workplace chemicals and carbon monoxide.

MedlinePlus lists the symptoms of anticoagulant rodenticide poisoning. Because the effect builds as clotting factors are used up, symptoms may not appear straight away. The NHS says symptoms of poisoning in general may take a few hours or days to start.

• Bleeding gums or nosebleeds.

• Blood in the urine or in the stools.

• Bruising and bleeding under the skin.

• Vomiting blood.

• Pale skin, low blood pressure and signs of shock.

• Confusion, lethargy or altered mental state, which may reflect bleeding in the brain.

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, if someone has lost consciousness or stopped breathing, has severe difficulty breathing, or has a seizure. It says to call NHS 111 if you are not sure whether something is harmful. It advises that you do not drive to A&E: ask someone to drive you or call 999 for an ambulance.

While waiting for help, the NHS advises you to start CPR if someone is unresponsive and not breathing, put an unconscious person who is still breathing in the recovery position and keep checking their breathing, and if they are awake keep talking to them. It also says to try to find what caused the poisoning by looking around for packaging, and to take some of the substance or its packaging to show doctors.

The NHS says not to try to make someone sick and not to give the person anything to eat or drink. MedlinePlus likewise says not to make a person throw up unless told to do so by poison control or a health care professional.

Information that helps the team is the person's age, weight and condition, the name of the product with its ingredients and strength if known, the time it was swallowed and how much was swallowed. This is MedlinePlus's list, and it is useful whichever service you contact.

MedlinePlus describes the emergency department approach. The provider measures and monitors vital signs including temperature, pulse, breathing rate and blood pressure, and blood and urine tests are done. Treatment depends on what is found, and the options it lists are summarised below.

The NHS says that if you do not have symptoms of poisoning, you may not need any treatment but may still need to be monitored for several hours in case you become unwell. Because anticoagulant poisoning can be delayed, that is not a reason to wait at home. If there is a chance that a child or adult has swallowed rat poison, get medical advice immediately through 999, A&E or NHS 111, and take the product packaging with you.

The NHS stresses that treatment depends on what has caused the poisoning and that you will need to be treated in hospital for poisoning because it can cause you to be seriously unwell and can be life threatening. It lists medicines called antidotes, a charcoal drink that can help stop some types of poisoning, treatments for symptoms such as fluids given into a vein, and removing the cause of the poisoning from the body.

MedlinePlus says death may occur as late as 2 weeks after the poisoning as a result of bleeding, but that getting the right treatment most often prevents serious complications. If blood loss has damaged the heart or other vital organs, recovery may take longer and the person may not fully recover.

That information is for background only. MedlinePlus is a US source and says that the article is for information and should not be used to treat or manage an actual poison exposure. In the UK, the correct response is to seek emergency or NHS 111 advice immediately.

The NHS gives general advice to prevent poisoning at home that applies to rodent baits as much as to cleaning products: store medicines and chemicals out of reach of children, ideally in a locked cupboard; read the instructions that come with products carefully; put safety catches on low cupboards that contain harmful substances; and keep chemicals in their original containers to avoid them being mistaken for drinks. It also advises wearing gloves, goggles or a mask to protect yourself when handling or using harmful chemicals, and keeping the packaging so that you can show doctors what was involved if something goes wrong.