Why is drinking alcohol a concern when I’m taking medicines?

Alcohol can interact with many medicines. This can change how both the alcohol and medicine affect you. This can happen even if you only drink one or 2 standard drinks a day.

How can alcohol affect my medicines?

There are 2 ways that alcohol can affect your medicines:

1. The alcohol interferes with how your body deals with the medicine. Your body might speed up or slow down the breakdown of the medicine.
2. The alcohol increases the effects of your medicine, particularly to your central nervous system (e.g., sedation).

Both problems can have serious consequences and can seriously affect your ability to:

• drive
• operate heavy machinery
• work safely

Your body takes many hours to process and remove the alcohol that you drink. Reactions between the alcohol and your medicines can happen at any time when you have alcohol in your body.

Which medicines cause problems with alcohol?

Many over-the-counter medicines and herbal medicines should not be taken with alcohol.

The most common medicines that react with alcohol are:

• opioids
• antidepressants
• antipsychotic medicines
• benzodiazepines
• sleeping tablets
• antihistamines
• cold and flu medicines
• some antibiotics (metronidazole, azithromycin and nitrofurantoin)

You should also be careful with pain relief medicines sleeping tablets and some travel medicines.

If you take any of these medicines with alcohol, you may get:

• nausea and vomiting
• headaches
• drowsiness or sleepiness
• dizziness and fainting
• blood pressure changes
• uncharacteristic behaviour
• poor or loss of coordination
• accidents

The effects of drinking alcohol and taking medicine depend on:

• the type and amount of medicine you are taking
• the amount of alcohol you drink
• your genetics, sex and health

Generally, females, older people and people with liver problems are more likely to have an alcohol-medicine interaction.

The sedative effects of alcohol and some medicines are additive. Medicines that can cause sedative effects include:

• all opioids
• some antidepressants
• all antipsychotics
• all sleeping tablets
• all anti-anxiety medicines
• antihistamines
• cold and flu medicines
• erectile dysfunction medicines
• antibiotics (metronidazole, azithromycin and nitrofurantoin)

These medicines depress your central nervous system. Drinking alcohol and taking these medicines puts you at risk of: weakened breathing, heavy sedation, coma and death. Alcohol can be very dangerous — even fatal — if you are taking these medicines.

It’s important to know how your medicine interacts with alcohol.

Sleeping tablets, some anti-anxiety and antidepressant medicines

Alcohol can increase the effects of medicines that relax or sedate your body. These can include: sleeping tablets and some anti-anxiety and antidepressant medicines.

Increased drowsiness and dizziness may make it harder for you to: think clearly, make you more likely to fall and affect your ability to do complicated things like drive a car.

Cough, cold, allergy and travel sickness medicines

Some medicines contain ingredients that can relax or sedate you. These can include:

• cough
• cold
• allergy
• travel sickness medicines

The ingredients may interact with alcohol to cause increased drowsiness and dizziness.

Pain relief medicines

Some pain relievers (including aspirin, celecoxib, ibuprofen and naproxen) can react with alcohol to cause:

• stomach upsets
• stomach bleeding
• ulcers

Regularly having more than 3 alcoholic drinks a day may increase your chance of problems with these medicines.

It’s always best to talk about the side effects of any new medicines with your doctor or pharmacist.

What are the complications of drinking alcohol and taking medicines?

Drinking alcohol and taking some medicines can cause serious complications such as:

• liver damage
• heart problems
• internal bleeding
• weakened breathing
• depression

Mixing alcohol and medicine can also make it dangerous to:

• drive
• operate machinery
• do physical activity

The risk of interactions between your medicines and alcohol increases as you get older. This is because older people:

• often take more medicines
• can’t metabolise medicines as well as younger people

Age also changes how your body works. It increases the chance of you having an interaction between alcohol and your medicine at a lower dose.

Can I drink and take my medicines safely?

Always read your medicine label. This is important for:

• prescription medicines
• over-the-counter medicines
• complementary (herbal) medicines

If it carries a warning, do not drink alcohol.

It’s best to get your doctor’s or pharmacist’s advice before you take any new medicine.

You can find out more about how alcohol will react with your medicine by reading the Consumer Medicine Information (CMI). You can get your medicine’s CMI by:

• asking your pharmacist or doctor to print it for you
• calling 1300 MEDICINE on 1300 633 424 (9am to 5pm, Monday to Friday, Eastern Standard Time)
• searching in healthdirect's medicines section
• searching NPS MedicineWise Medicines finder
• getting in touch with the maker of your medicine — the company details are on their Australian website

If you are concerned or unsure about the effects of alcohol with any medicine, talk to your: doctor, pharmacist or other health practitioner.