How can alcohol affect my medicines?

Alcohol can interact with many medicines. This can change how both the alcohol and the medicine affect you.

Alcohol and many medicines are processed by your liver. Combining them can alter this process.

Alcohol also depresses your central nervous system (CNS). This means that it slows down your brain activity and the messages your brain sends to your body. When combined with medicines that also depress your CNS, the effect is stronger and can be very dangerous.

Alcohol affects different medicines in different ways. Effects could include:

• worsening side effects of the medicine
• causing a severe toxic reaction
• making the medicine less effective
• serious illness or death

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 medicines can cause problems with alcohol. This includes prescription medicines as well as over-the-counter and complementary (herbal) medicines.

Medicines that slow your brain activity and are unsafe to take with alcohol include:

• benzodiazepines — including anti-anxiety medicines and sleeping tablets
• opioids such as codeine
• many antidepressants
• some antihistamines such as promethazine and doxylamine — these are often used in over-the-counter medicines for allergies, cold and flu symptoms and motion sickness

Other medicines that interact with alcohol include:

• antipsychotic medicines
• some antibiotics — such as metronidazole, tinidazole, doxycycline, erythromycin, isoniazid and linezolid

Some medicines can be safely taken with an occasional drink but can cause problems if you drink on a regular basis or if you have a large amount of alcohol. These include:

• some blood pressure medicines
• blood-thinning medicines
• some diabetes medicines
• non-steroidal anti-inflammatory medicines (NSAIDs)

Always check with your doctor before you combine medicines and alcohol.

What are the effects of combining alcohol with medicines?

The effects of drinking alcohol while you are taking medicine depend on:

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

LOOKING FOR A MEDICINE? — To search by brand name or active ingredient, use the Medicines information search feature.

Benzodiazepines and opioids

Drinking alcohol when taking benzodiazepines or opioids can lead to:

• drowsiness
• dizziness
• difficulties with movement and coordination
• a high risk of accidents and falls
• slowed breathing and heart rate
• overdose and death

Mixing alcohol with these medicines can make it dangerous to:

• drive
• operate machinery
• do physical activity

Antidepressants

Many antidepressants can cause drowsiness, dizziness and memory problems if combined with alcohol. It could be dangerous for you to drive or operate machinery.

If you take an antidepressant, ask your doctor about your specific medicine.

Antihistamines

There are different types of antihistamines. Some of them can make you drowsy. Combining them with alcohol can lead to:

• becoming more drowsy
• dizziness
• difficulty with movement and coordination

Antipsychotics

Mixing alcohol with antipsychotic medicines can cause:

• worse side effects of your medicine
• drowsiness
• dizziness
• problems with concentration and thinking
• seizures
• dangerous changes in your heart rate, breathing, blood pressure and body temperature
• a higher risk of suicide

Antibiotics

Mixing alcohol with metronidazole, tinidazole or isoniazid can lead to unpleasant effects, such as:

• drowsiness and dizziness
• abdominal pain
• nausea
• sweating and hot flushes
• headache
• palpitations

You may need to wait 2 to 3 days after finishing a course of antibiotics before you drink again.

Some other antibiotics can be affected by alcohol too. If you are taking antibiotics and you plan to drink, always check with your doctor whether it's safe.

Non-steroidal anti-inflammatory medicines (NSAIDs)

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

• abdominal pain
• bleeding in your stomach
• stomach ulcers

The risk depends on many individual factors. Ask your doctor whether it's safe for you to have a drink when you take these medicines.

Medicines for diabetes

If you take insulin, metformin or some other medicines for diabetes and you drink alcohol, you could develop low blood sugar. Alcohol can also make it difficult to notice the symptoms of low blood sugar.

If you have diabetes, ask your doctor if it's safe for you to drink. Never drink alcohol without food.

Who is at risk?

Anyone could suffer the effects of an interaction between alcohol and medicine, but females and older people are at higher risk.

As you get older, your body takes longer to process alcohol. You become more sensitive to the effects of alcohol and medicines. Older people are also more likely to take medicines daily. It's important to be careful and talk to your doctor about your risk.

Can I drink and take my medicines safely?

Never drink alcohol when taking medicine unless you have checked that it is safe.

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.

If you're not sure, talk to your doctor or pharmacist.

Resources and support

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 from 9am to 5pm (AET), Monday to Friday
• searching in healthdirect's medicines information section
• searching the NPS MedicineWise Medicine Finder

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

If you are pregnant or breastfeeding and would like to find out more about your medicines call Medicines Line on 1300 633 424.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Do you prefer to read in languages other than English?

Find information about alcohol in many other languages, provided by the Alcohol and Drug Foundation.

Looking for information for Aboriginal and/or Torres Strait Islander people?

The Alcohol and Drug Foundation has factsheets about alcohol and benzodiazepines.