Accidental overdose of medicine

What is an accidental overdose of medicine?

Taking too much of a medicine is known as an overdose. More Australians are dying from accidentally overdosing on medicines than ever before. Taking too much of a medicine can be very dangerous, and even life-threatening, but accidental overdoses can be prevented.

Most medicines have risks as well as benefits. Medicines are toxic (harmful) if you take too much. Some medicines can also be toxic if you take them at the same time as alcohol or some other medicines.

An accidental overdose can happen if:

• you take a medicine by mistake
• you use the wrong medicine by mistake
• you take too much of a medicine by mistake
• you take a medicine together with another medicine or alcohol which cause a harmful reaction if they are combined

Accidental overdoses can also happen during medical or surgical procedures.

How can accidental overdose happen?

The more medicines you take, the more you’re at risk of harm from them. In recent years, more than 1 in every 2 deaths from accidental overdose have involved a person taking 3 or more substances.

You are more at risk of accidental overdose if:

• you are taking a combination of different medicines
• you don’t follow the instructions of your doctor or pharmacist properly
• you mix medicine with alcohol.

There are mistakes that can mean overdose is more likely:

• Taking more than one medicine with the same active ingredient (for example, 2 cold and flu medicines might have different brand names but both contain paracetamol, which means you will take double the dose if you take both).
• Taking medicine that is stronger than you thought (for example, medicines with the same brand name may come in different strengths, meaning that a tablet in one package contains a higher dose of medicine than a tablet in a different package).
• Using the wrong measuring device for the medicine (for example, using a tablespoon rather than a teaspoon means you take more than you need).
• Forgetting how much medicine you’ve already taken.

Your child is more at risk of accidental overdose if:

• you incorrectly calculate your child’s dosage of medicine based on their weight
• you don’t store a medicine safely, meaning that your child can reach the medicine and accidentally swallow it

It’s always important to read the label, even if you have taken the medicine before.

What are the symptoms of an overdose of medicine?

The symptoms of a medicine overdose depend on the type of medicine. If someone has overdosed, 

Call or ask for an ambulance if someone:

• is not breathing, or their breathing is shallow
• appears to be unconscious, can’t be woken up, is snoring or gurgling
• appears to be confused
• has blue lips or fingertips
• has a seizure
• has floppy arms and legs, or cool, clammy skin
• has pinpoint-sized pupils

Which medicines are the most dangerous?

It’s important to be careful with all medicines, but some are more dangerous or involved in more overdoses than others.

Opioids

Opioids, such as the strong pain medicines oxycodone and fentanyl, are the most common cause of fatal accidental overdoses in Australia. The risk is higher if you are also drinking alcohol or taking other medicines at the same time, in particular benzodiazepines (such as diazepam and alprazolam), antidepressants or antipsychotics.

Paracetamol

Paracetamol is the most common cause of people being admitted to hospital for accidental overdose. Paracetamol is also one of the most common causes of accidental overdose in children. Taking too much paracetamol can lead to yellow eyes and skin (jaundice), loss of coordination, liver damage and even death. It’s important to get medical help as quickly as possible if you think you or your child have taken too much paracetamol, as the damage can happen even before you notice any symptoms.

Benzodiazepines

Benzodiazepines, such as diazepam and temazepam, are the second most common cause of accidental overdoses resulting in death, mostly when they are combined with other substances. The risk is higher if they are taken with alcohol, or if they are taken with many other medicines, including opioids and some over-the-counter medicines.

Diabetes medication

If you have diabetes, taking too much insulin or other diabetes medicines can cause your blood sugar level to drop too low. This can develop into a serious situation — ask your doctor or diabetes educator what to do if this happens to you. It’s also dangerous for people who don’t have diabetes to take these medicines.

What should I do if someone has overdosed?

If someone has taken a medicine and is unresponsive, don’t assume they are just asleep — an overdose is a medical emergency.