Drug overdose Ratonga-rawa pūroi

A drug overdose happens when someone takes a poisonous amount of a drug or medicine. The effect of the overdose will depend on what type of drug has been taken. Drug overdoses can be life-threatening.

A drug overdose is a medical emergency

If you think someone has overdosed on a drug or drugs, call 111 and ask for an ambulance.


Types of drug overdose

A drug overdose may be deliberate or accidental. The drug can be:

  • a prescribed medicine
  • an over-the-counter medicine
  • a recreational drug.

You can overdose on drugs that can be:

  • swallowed
  • breathed in
  • injected.

The drugs that most commonly cause accidental overdose in Aotearoa New Zealand include:

  • opioids including morphine, methadone, heroin, codeine and fentanyl
  • alcohol
  • benzodiazepines
  • paracetamol (the most common drug poisoning in young tamariki).

Safe use of paracetamol — KidsHealth

Alcohol poisoning


Symptoms of a drug overdose

The signs and symptoms of a drug overdose will depend on what and how much they have taken. Overdosing on some drugs will quickly cause symptoms, and others develop over time. 

Symptoms may include:  

  • confusion — they may claim to hear voices or see things
  • sleepiness, which can lead to them losing consciousness
  • unusually small or large pupils
  • stomach pain
  • feeling sick and throwing up
  • difficulty breathing
  • overheating and sweating
  • excitable behaviour
  • shaking hands.

Helping someone who has taken a drug overdose

  • Call 111 and ask for an ambulance.
  • Stay calm and reassure the person.
  • If they are conscious, get them into a comfortable position.
  • If they are not conscious but breathing, follow the steps on this page.
    Unconscious but breathing
  • If they are not breathing, start CPR.
    CPR (resuscitation)
  • If possible, try to find out what they have taken and how much. If there are any containers or syringes, keep them to give to ambulance staff.
  • Stay with them and wait for the ambulance.

Helping someone after a recent overdose

If someone tells you they took an overdose in the last couple of days, make sure they go to their healthcare provider for an urgent assessment, even if they say they are fine. This is very important as overdosing on some drugs may not cause obvious symptoms, but it can still cause serious damage to their body. The healthcare provider will also look into why they took the overdose, and help them if it was deliberate.