Poisoning

Poisoning means harm from a substance that has got into the body — swallowed, breathed in, or absorbed through the skin. Medicines and household chemicals cause most cases; less often it is carbon monoxide, mushrooms, solvents, or products used against insects and rodents. The hard part is that during the first few hours the severity is almost invisible from outside: someone can look perfectly well while the poison is already at work.

When to call an ambulance straight away

Call 112, the single European emergency number, if the person has any of these signs:

• does not respond to voice or touch, and does not come round;
• is not breathing, or breathing is slow, gasping, with pauses;
• is choking, cannot finish a sentence, lips or face turning blue;
• has had a fit (seizure);
• burning pain in the mouth, throat or behind the breastbone, drooling, burns or blisters on the lips — this is how a swallowed corrosive behaves;
• confusion that keeps getting worse: does not know where they are, does not recognise family, is rambling;
• a very slow or very fast pulse, cold clammy skin, sudden weakness on trying to stand.

An ambulance is also needed with no symptoms at all in three situations: a small child has swallowed a medicine or a chemical; a child may have swallowed a button battery or several magnets (a battery burns through the gullet within hours, and magnets pulling towards each other through the bowel wall tear it); someone has taken a medicine deliberately to harm themselves — here it does not matter how many tablets they say they took.

Do not drive a seriously unwell person yourself: they may vomit or lose consciousness on the way, with nobody free to help.

What to do while help is on the way

Your own safety comes first. If gas, solvent fumes or smoke are involved, going in unprotected simply adds a second casualty. Open the windows, get the person into fresh air, and come out yourself. Then act according to their state:

• unresponsive and not breathing — start cardiopulmonary resuscitation and keep going until the crew arrives;
• unconscious but breathing — roll them into the recovery position so vomit cannot enter the airway, and keep watching the breathing;
• conscious — keep talking, do not leave them alone, do not let them fall asleep unattended.

If the substance has landed on the skin, take off the soaked clothing without pulling it over the head and rinse the area under cool running water for at least fifteen minutes. If it has got into an eye, rinse for the same length of time with a gentle stream from the inner corner outwards; take out a contact lens first if it comes away easily.

Gather anything that helps identify the substance: packets, blister strips, bottles, leftover liquid. Take it to hospital — the name and the amount are what let the doctor choose an antidote. Note the time the substance went in and the time the first symptoms began. If there is vomiting, keep a small sample in a sealed container.

What not to do

The home remedies handed down through families usually make poisoning worse rather than better.

• Do not make the person sick. A corrosive burns the gullet a second time on the way back up, petrol and solvents run into the lungs, and a half-conscious person chokes on the vomit. Ipecac syrup, once used for this, has been dropped from practice.
• Do not try to neutralise the poison. Bicarbonate on an acid or vinegar on an alkali sets off a violent reaction, with heat and gas, inside an already burnt stomach.
• Do not give milk or oil. Fat speeds up absorption of some poisons, and a full stomach makes it impossible to inspect the burn from inside.
• Do not give food or drink without medical instruction — with impaired consciousness this is the direct route for fluid to reach the lungs.
• Do not hand out activated charcoal just in case. It does nothing against alcohols, acids, alkalis, iron or petroleum products, while it does make endoscopy harder and raises the risk of aspiration.
• Do not wait and see. Time is the one resource in poisoning that cannot be recovered.

Why feeling fine proves nothing

The most dangerous poisons are the delayed ones. For the first few hours the person is bright, refuses to go to hospital, and the treatment window quietly closes.

• Paracetamol. On the first day there may be mild nausea, sometimes nothing at all. The liver starts to fail on the second or third day, and by then there is little left to treat with. The antidote is acetylcysteine, and the earlier it starts the more complete the protection; the decision rests on the blood level and the time of the overdose, not on how well the person looks.
• Methanol and antifreeze. For several hours the picture resembles ordinary drunkenness. Then severe acidosis develops; methanol takes vision, sometimes permanently, and ethylene glycol takes the kidneys. Treatment exists, but only works in time.
• Death cap and its relatives. Nothing happens for the first hours after the meal. Half a day later come heavy vomiting and diarrhoea, then a deceptive improvement, then liver failure. Symptoms that start late after eating mushrooms are far more worrying than symptoms that start at once.
• Modified-release tablets. The coating dissolves gradually, and the peak effect arrives about the time the person has decided to go home.
• Carbon monoxide. The clue is that outdoors things improve and at home the headache and nausea return, and that the same complaints hit the whole household, and the cat, at once. An ordinary fingertip pulse oximeter reads normal in this poisoning and reassures for no reason.

Hence the rule: feeling well, and even a normal first set of blood tests, does not rule the diagnosis out. Whether observation is needed, and for how long, is decided by the substance and the clock, not by how the person looks.

What people are poisoned by most often

• Medicines. Painkillers containing paracetamol, anti-inflammatories, sleeping tablets and sedatives, antidepressants, opioid painkillers, heart and blood pressure drugs, diabetes medicines. A common and avoidable cause is the double dose: the same active ingredient turns up in two products with different names, say a fever tablet and a cold remedy sachet.
• Household chemicals. Drain and oven cleaners, which are concentrated alkalis; descalers and rust removers, which are acids; bleach; laundry capsules, soft and brightly coloured, which children put in their mouths.
• Alcohol and its substitutes, and recreational drugs, especially of unknown composition.
• Carbon monoxide. A faulty water heater, a blocked flue, a stove damped down too early, a generator or barbecue brought indoors.
• Mushrooms and plants. Deadly mushrooms have edible lookalikes, and identification apps get it wrong.
• Insect and rodent products — organophosphates and baits that thin the blood.
• Fumes and gases. Solvents and glues in a closed room; chlorine, released when bleach is mixed with an acidic cleaner.

What looks like poisoning but is not

Confusion, vomiting and sudden weakness do not only come from poison. Until the cause is clear, keep in mind several conditions where hours matter:

• stroke — the face drops on one side, an arm or leg goes weak on that side, speech becomes slurred;
• low blood sugar in someone with diabetes — sweating, trembling, aggression or drowsiness, all settling quickly after something sweet;
• meningitis and sepsis — high temperature, severe headache, dislike of light, a rash that does not fade under pressure;
• head injury — a fall or blow others may not know about, with drowsiness building over hours;
• an epileptic seizure and the dazed state that follows it;
• diabetic ketoacidosis — thirst, passing a lot of urine, deep noisy breathing, a smell of acetone;
• gut infection — if vomiting and diarrhoea began a day after the meal and the whole party is ill, this is microbes rather than chemicals.

You are not expected to tell these apart. Doubt on its own is reason enough to call an ambulance: a clinician on the scene will sort it out faster.

What happens in hospital

The person is dealt with before the poison: the airway is secured, oxygen is given, a drip is put up, an ECG is recorded, blood sugar in mmol/L is checked. Then the laboratory takes over — blood levels of the substance where they can be measured, acid-base balance, salts, liver and kidney function. Treatment depends on the substance and may include:

• activated charcoal by mouth or tube, if little time has passed and the poison binds to it;
• antidotes: acetylcysteine for paracetamol, naloxone for opioids, atropine for organophosphates, vitamin K for anticoagulant rat poison, oxygen under pressure for carbon monoxide;
• supportive treatment — fluids into a vein for dehydration, anticonvulsants, warming or cooling, drugs to hold up the blood pressure;
• cleaning the blood by machine in selected cases such as methanol, lithium or large doses of salicylate.

With no symptoms, no treatment may be needed, but the person is still kept under observation for a period set by the substance. After a deliberate overdose a mental health assessment is always offered — it is part of the treatment, not a formality.

How to make the home safe

• Keep medicines in a locked cupboard, not in a bedside drawer or a handbag where a child goes looking for sweets.
• Keep chemicals in their original containers only. Anything decanted into a juice bottle will eventually be drunk.
• Fit safety catches on low cupboards holding cleaning products, and put laundry capsules up high.
• Check where the button batteries are: remote controls, scales, musical picture books, light-up toys. The battery compartment should close with a screw.
• Fit a carbon monoxide alarm wherever there is a water heater, boiler, stove or fireplace, and have the flue checked once a year.
• Never mix cleaning products, and do not use them in a closed bathroom without ventilation.
• Read the ingredients, not just the name on the box: that is how you avoid taking the same active ingredient twice.
• Return out-of-date medicines to a pharmacy rather than letting them pile up.

Online consultation

An online appointment fits where there are no emergency signs but there is a question that needs a doctor: going through the medicine cabinet to see whether active ingredients are being duplicated; judging the risk after a child licked a cleaning product and is behaving normally; working out when to return to a normal diet after a mild gut infection; discussing which painkiller is safe when the liver is already damaged; planning how to store medicines when there are small children in the house, or someone with memory problems.

The doctor will go through the composition of what was taken, say which signs to watch for and over what period, and advise whether a face-to-face examination is needed. But if any of the signs in the first section are present, do not spend time writing — call an ambulance.

This material is for information only and does not replace medical advice.