Antibiotics have been available to the general public since about 1950, and since about 1950 doctors have been telling patients to avoid alcohol when taking them.
There was a kind of sensibility in the recommendation to avoid alcohol when taking penicillin in the 1950's, when one of the main uses of penicillin was to treat gonorrhea. In that era, people tended to have flings when they got drunk, and doctors thought that if their patients didn't get drunk, then they wouldn't keep contracting sexually transmitted diseases.
It turns out, a study found in 2008, that people really do pick up more STDs when they drink, particularly if they indulge in binge drinking. However, there generally isn't a pharmacological reason to avoid drinking alcohol when taking most antibiotics. There are just a few exceptions.
The package inserts for most antibiotics include a warning for patients to avoid using alcohol. However, different antibiotics react with alcohol in different ways. For example, some antibiotics induce flushing (redness in the face) after drinking alcoholic beverages, but most antibiotics do not. The antibiotic erythromycin increases alcohol absorption in the intestine by increasing the rate at which the stomach empties into the small intestine. Persons taking the antituberculosis drug isoniazid need to abstain from alcohol, because this drug can cause liver damage, which may be exacerbated by daily consumption of alcohol. Other than these effects, however, moderate alcohol consumption, one or at most drinks a day for women and two or at most three drinks a day for me, probably does not interfere with antibiotic effectiveness.
Alcoholics are more susceptible certain kinds of infections. They may need more antibiotics and a longer course of treatment. These effects are not likely to be a problem for people who drink moderately or who do not drink at all.
What are the interactions of specific antibiotics and alcohol?
Anti-infective drugs including metronidazole (Flagyl, Metronide or Metrogyl), tinidazole (Fasigyn or Simplotan) and sulfamethoxazole/trimethoprim (Bactrim, Co-trimoxazole) don't mix well with alcohol. You won't have any real problem avoiding alcohol when you are on these medications, because the reason they don't mix with alcohol is they block the pathway through which the liver metabolizes acetaldehydes. These are the chemicals that give you a hangover. If you drink when you are taking Bactrim, Cotrimoxazole, Fasigyn, Flagyl, Metrogyl, Metronide, or Simplotan, you'll get a much worse hangover than usual. Willpower to avoid drinking is easy to find once you have had that experience.
Alcohol dilates your blood vessels. This cools you down, and interferes with your body's attempts to use fever to slow the spread of an infection. Dilating your blood vessels forces more blood through your kidneys. If you have the flu or certain other kinds of viral infections, the deep, aching muscle pain produced by the infection is more likely to lead to serious and lasting muscle damage when combined with binge drinking.
Some antibiotics, notably isoniazid and flucloxacillin (Flopen, Staphylex), cause mild cases of hepatitis in a subset of people who use them. A boozy night out on the town could make this hepatitis worse. You could feel like you are coming down with something else, when what you really need to do is to avoid drinking.
If you happen to be on one of the previously mentioned "problem antibiotics," then it's a good idea just to avoid alcohol altogether until you have taken all of the antibiotics your doctor prescribed. Otherwise, a single drink of beer, wine, or vodka isn't likely to do you much harm.
Still have something to ask?
Get help from other members!