It's sensible to avoid drinking alcohol when taking medication or feeling unwell. But it's unlikely that drinking alcohol in moderation will cause problems if you're taking most common antibiotics.

To reduce the health risks associated with drinking alcohol, men and women are advised not to regularly drink more than 14 units a week.

When to avoid drinking alcohol completely

Completely avoid drinking alcohol when taking:

• metronidazole – an antibiotic sometimes used to clear dental or vaginal infections, or to clear infected leg ulcers or pressure sores
• tinidazole – an antibiotic sometimes used to treat many of the same infections as metronidazole, as well as to help clear bacteria called Helicobacter pylori (H. pylori) from the gut

Alcohol can cause a serious reaction when combined with these medications. Symptoms of this reaction can include:

• feeling or being sick
• tummy pain
• hot flushes
• a fast or irregular heartbeat
• headaches
• dizziness
• drowziness

Because of this risk, you should avoid alcohol while you're taking these medications. You should continue to avoid alcohol for 48 hours after you stop taking metronidazole and 72 hours after you stop taking tinidazole.

Things like mouthwash and other medicines sometimes contain alcohol, so you should also avoid using these while you're taking metronidazole or tinidazole.

Other antibiotics that can interact with alcohol

There are some antibiotics that can sometimes interact with alcohol, so you should be wary of drinking alcohol if you're taking:

• linezolid – linezolid can interact with undistilled (fermented) alcoholic drinks, such as wine, beer, sherry and lager
• doxycycline – this is known to interact with alcohol, and the effectiveness of doxycycline may be reduced in people with a history of chronic alcohol consumption; it should not be taken by people with liver problems

Side effects

Some antibiotics have a variety of side effects, such as causing sickness and dizziness, which might be made worse by drinking alcohol.

It's best to avoid drinking alcohol while feeling unwell anyway, as the alcohol itself can make you feel worse.

Both metronidazole and tinidazole can cause drowsiness. Check with your pharmacist whether your antibiotic could make you drowsy.

You should not drive or operate machinery if you're taking an antibiotic that makes you drowsy.

Advice about your medication

Check with your GP or pharmacist when you're given your prescription if you're unsure about whether or not you can drink alcohol while you're taking antibiotics. You can also phone NHS 111 for advice.

Further information:

• Can I take paracetamol if I'm on antibiotics?
• When can I drink alcohol after finishing metronidazole?
• What if I miss a dose of antibiotics?
• Will antibiotics stop my contraceptive pill working?
• eMC database of medicine patient information leaflets