Alcohol can interact with some medicines, including those you can buy over the counter. Some of these interactions can be harmful or stop your medicine from working properly, so it’s important to know when it isn’t safe to mix the 2.
How are medicines and alcohol metabolised?
Your liver breaks down much of the food, drinks, medicines and alcohol that enter your body. It does this through chemical reactions in the cells.
Drinking alcohol can interfere with this process. It can make some medicines less effective, and some can become toxic.
There’s also the risk that alcohol enhances the side effects of some medicines and make them worse.
Problems from alcohol interacting with medicines
Problems can happen with many different medicines. The most common ones are antibiotics, antidepressants, painkillers, sleeping tablets and certain antihistamines used in cough and cold remedies as well as some travel and allergy medicines.
If you take the wrong medicine with alcohol, you can get:
- nausea and vomiting
- drowsiness or sleepiness
- dizziness and fainting
- blood pressure changes
- uncharacteristic behaviour
- poor or loss of coordination
It can take time for your body to metabolise alcohol and medicines, so you can have these symptoms even if you don’t take the medicine at exactly the same time as consuming alcohol.
There is a risk of serious complications such as:
Combining alcohol and medicine can make it dangerous to operate machinery, drive or do physical activity.
Who is at greatest risk?
Women, older people and those with liver problems are at greatest risk. You are also at greater risk of you:
- drink a lot of alcohol
- are small
- aren’t healthy
- are taking a lot of different medicines
Safe use of medicines and alcohol
Always read the label of your medicine, including over-the-counter and herbal medicines. If it carries a warning, avoid alcohol.
Be very careful about drinking alcohol if you are taking benzodiazepines, methadone or other medicines that depress the central nervous system. Alcohol can be very dangerous — even fatal — if you are taking these medicines.
It’s also best to seek doctor’s or pharmacist’s advice if you are unsure, and before you take any new medicine, including complementary (sometimes called natural or herbal) medicines.
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Last reviewed: May 2020