Thought Leaders Dr. Janette Randall Chair of NPS MdicineWise

How many antibiotics can interact with alcohol?

As a GP, I get asked this question a lot. Contrary to popular belief, there are only a handful of antibiotics that can interact with alcohol to cause unpleasant effects.

The two main antibiotics you should definitely avoid drinking alcohol with are metronidazole (brand names include Flagyl) and tinidazole (brand names include Fasigyn). These antibiotics are used to treat various infections including:

dental and vaginal infections

infected leg ulcers and pressure sores

some stomach or gut infections

Other antibiotics that may cause adverse effects when taken with alcohol are co-trimoxazole (also called trimethoprim with sulfamethoxazole; brand names include Bactrim) and linezolid (Zyvox). Co-trimoxazole is used to prevent and treat whooping cough and other bacterial infections. Linezolid is a rarely used antibiotic but may be required to treat serious infections when other antibiotics are not suitable.

By what mechanism does alcohol cause these symptoms?

Metronidazole and tinidazole may interfere with the break down of alcohol in the body, and can cause unpleasant symptoms like nausea, vomiting, skin flushes, headaches, or a fast or irregular heartbeat. Drinking large amounts of alcohol with co-trimoxazole can cause a similar reaction, but this is rare.

Linezolid interacts with alcohol in a different way. Alcoholic drinks that are rich in a chemical called tyramine (including wine, beer, sherry or lager) can interact with linezolid to raise blood pressure. For this reason you should avoid these alcoholic drinks while taking linezolid. Other tyramine-rich foods should also be avoided with linezolid including mature cheese, soy sauce, and yeast and meat extracts.

So can you have a drink as soon as you’ve finished a course of metronidazole or tinidazole?

It’s actually best not to as these antibiotics may still interact with alcohol several hours after completing your course. You should avoid drinking alcohol for at least 24 hours after finishing a prescribed course of metronidazole, and at least 72 hours after finishing a prescribed course of tinidazole.

Where can people find more information on whether they can drink alcohol with their prescribed antibiotic?

People can ask their pharmacist, doctor or nurse about drinking alcohol with their antibiotic.

You can also speak to a health professional at NPS Medicines Line on 1300 633 424 to get information about your prescription, over-the-counter and complementary medicines (herbal, ‘natural’, vitamin and mineral supplements). The service is available from anywhere in Australia for the cost of a local phone call, Monday to Friday, 9am to 5pm AEST.

Can antibiotics react with other medicines that a person may be taking?

Yes they can. Antibiotics like most other medicines have the potential to interact with some other medicines, including complementary medicines. They may also interact with food and drinks other than alcohol, such as milk. It’s always a good idea to ask your health professional about what else may interact with your antibiotic if you’re unsure.

If you get vomiting or diarrhoea from taking antibiotics it may affect the absorption of other medicines so if you’re concerned, check with your doctor or pharmacist.

What other advice would you give to people taking antibiotics?

Although drinking alcohol in moderation with most antibiotics is not usually a problem, it’s best — and makes sense — to avoid drinking alcohol until you recover from your illness.

And while it’s important to find out about possible interactions between your antibiotic, other medicines and alcohol, it’s just as important to know how to take your course of antibiotics correctly.

Antibiotic resistance is a huge problem globally, and unless we use antibiotics properly it is quite possible that we will return to a pre-antibiotic era where these lifesaving medicines no longer work for even simple infections.

So if you are prescribed a course of antibiotics this party season, make sure you complete the full course and take them exactly as directed. Drinking alcohol may lead you to forget to take your antibiotics at the right time, and to skip doses. If everyone takes action and uses antibiotics properly, we can help reduce the spread of antibiotic-resistant bacteria.

Where can readers find more information?

You can read more about antibiotics, including information on drinking alcohol while taking antibiotics by visiting the NPS MedicineWise website.

About Dr Randall

Dr Janette Randall is the chair of NPS MedicineWise and a General Practitioner in Brisbane. She has worked in General Practice on a full and part time basis since 1994, and obtained her General Practice Fellowship in 1996. She has a special interest in mental health issues, and has done additional training in this area.

She has been significantly involved in the Divisions of General Practice Program since 1997, having held various roles with her local Division of General Practice in Qld. For six years she was a Board member of the State based representative body for Divisions in Qld, retiring in October 2006.

Janette was appointed to the NPS Board in May 2006 as a GP class Director and held the position of NPS Audit Committee Chair until October 2007. Janette has been Chair of the NPS Board since August 2007 and is the Board's representative on the MedicineInsight Advisory Group.