When I was in medical school we were told this story about alcohol and antibiotics:

A certain Brigadier Sir Ian Fraser, introduced the use of penicillin for injured soldiers in North Africa during World War II. At the time penicillin was in such short supply that after a patient had taken it, the drug was retrieved from his urine and recycled. Recuperating soldiers were allowed to drink beer but, unfortunately, this increased the volume of their urine making it harder to obtain the penicillin and, according to the Brigadier, led commanding officers to ban beer.

It’s a good story and may be a myth, however, it has given rise to many misconceptions regarding alcohol and antibiotics.

A survey done in a London genitourinary clinic of more than 300 patients found that 81% of people believe that alcohol will stop antibiotics working, while 71% believe that they will cause adverse reactions.

Except for a very small number of antibiotics neither of these beliefs is true. The fear for doctors is that these erroneous beliefs might make patients skip their medication over a glass of wine. Anything that encourages people to miss doses of antibiotics adds to the serious problem of antibiotic resistance. Encouraging those on the antibiotics who cannot resist a glass or two to complete their courses of treatment could help counter the spread of antibiotic resistance.

So having one glass of wine with your meal is probably not going to make a difference , except as described below with certain antibiotics. But doctors also fear that people will not stop at one drink and therefore put themselves at risk for making themselves feel worse when they are already feeling poorly.

In general then, most antibiotics can be taken safely with small amounts of alcohol as the majority of the most commonly prescribed antibiotics are not affected by alcohol, however, there a few aspects of alcohol, illness and antibiotics to consider before you fill that glass!

1. There are very few antibiotics that interact significantly with alcohol to produce adverse reactions

Alcohol should be completely avoided with these antibiotics:

• Metronidazole & tinidazole Alcohol taken with these antibiotics can cause a serious reaction including the following symptoms, breathlessness, headaches, chest pain, skin flushing, increased or irregular heartbeat, lightheadedness and nausea and vomiting. It is likely safe to resume alcohol 48 hours after the last dose.
• Co-trimoxazole Drinking alcohol while taking co-trimoxazole can occasionally cause a similar reaction to that of metronidazole or tinidazole, although this is very rare. Drinking alcohol in moderation does not normally cause a problem.
• 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

2. Alcohol intensifying the side effects of antibiotics

Many antibiotics can cause nausea, vomiting, diarrhoea, headaches and dizziness. Some can cause sedation, drowsiness and confusion. Some people experience these same side effects, interestingly, if they drink enough alcohol. The combination of alcohol and antibiotics may produce intensified side effects of the antibiotic at lower levels of alcohol intake.

2. Alcohol intensifying the symptoms of the disease

Imbibing alcohol to intoxicating levels, is not going to help your recovery when you’re ill. It can make you tired and dehydrated, but not because of any interaction with the antibiotic. The alcohol may also hinder the body’s natural ability to heal itself.

4. Small likelihood that alcohol might reduce the effectiveness of the antibiotic erythromycin. There is some evidence of a minor interaction with alcohol, which may slightly reduce or delay the effect of erythromycin.

5. Antibiotic intensifying the effect of alcohol

Additionally, some antibiotics, like erythromycin causes the stomach to empty more quickly, leading to faster alcohol absorption in the intestine and an increased effect of the alcohol.