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Interactions - Antibiotics

Antibiotics can sometimes interact with other medicines or substances. This means it can have an effect that is different to what you expected.

If you want to check that your medicines are safe to take with your antibiotics, ask your GP or local pharmacist.

Some antibiotics need to be taken with food, while others need to be taken on an empty stomach. Always read the patient information leaflet that comes with your medicine.


It's a good idea to avoid drinking alcohol when taking medicine or feeling unwell.

But it's unlikely that drinking alcohol in moderation will cause problems if you're taking the most common antibiotics.

However, some antibiotics can have side effects such as feeling sick or dizzy, which might be made worse by drinking alcohol.

Ask your GP or pharmacist if you're unsure whether you can drink alcohol while taking antibiotics.

Metronidazole and tinidazole

It's best to completely avoid alcohol while taking:

  • metronidazole – an antibiotic sometimes used for dental or vaginal infections, skin infections, infected leg ulcers and 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

Continue to avoid alcohol for 48 hours after you stop taking metronidazole and 72 hours after you stop taking tinidazole.

Drinking alcohol with metronidazole or tinidazole can cause very unpleasant side effects, such as:

  • feeling and being sick
  • stomach pain
  • hot flushes
  • a fast or irregular heartbeat
  • headaches
  • feeling dizzy
  • feeling drowsy

Other antibiotics

It may be best to avoid drinking alcohol if you're taking:

  • linezolid – this medicine can be affected by undistilled (fermented) alcoholic drinks, such as wine, beer, sherry and lager
  • doxycycline – alcohol can affect this medicine, and it may also be less effective in people with a history of drinking heavily

The contraceptive pill

Some antibiotics, such as rifampicin and rifabutin, can reduce the effectiveness of the combined contraceptive pill.

If you're prescribed rifampicin or rifabutin, you may need to use additional contraception, such as condoms, while taking antibiotics. Speak to your GP, nurse or pharmacist for advice.

Mixing medicines

Some antibiotics do not mix well with certain medicines and herbal supplements.

You may be prescribed a different antibiotic or told to stop taking some medicines or herbal supplements.

Always read the patient information leaflet that comes with your medicine and tell your doctor if you're taking any medicines or herbal remedies.

Page last reviewed: 11 November 2022
Next review due: 11 November 2025