Not drinking on antibiotics is one of those common-sense health rules that's a fact just because, like waiting 30 minutes after eating to swim, or peeing on a jellyfish sting to make it better.
It's also a great excuse to use if you don't feel like going out one night; most people will accept it as legit.
But is it actually true? After all, people certainly do it, and while there are some anecdotal stories about feeling the alcohol kick in harder, it's not like people are going to the hospital in droves after mixing the two.
The advice dates back to the (horny) 1950s
When antibiotics were invented, they were literally super-drugs. Suddenly, previously devastating illnesses, from common hospital infections to syphilis, could be cured in a matter of days or weeks. Needless to say, this drastically changed prescription drugs and how patients interacted with them.
Speaking of syphilis, it and other STDs caused by bacteria could finally be rapidly cured by antibiotics! Hooray! Everyone go out and celebrate by having more sex!
Well, not so fast -- when the relatively new antibiotic penicillin was administered to treat people with raging STDs in the 1950s and 1960s, patients were told to refrain from drinking so they'd keep it in their pants and not spread the infection before it cleared up. There was no chemical interaction that would render the drugs ineffective, or the alcohol exceedingly effective.
So it's all about sex?
Kind of! Basically, if a guy went out to knock back a few in honor of his seemingly cured clap, he might still be contagious and more likely to make some poor decisions. This stuffy attitude toward drinking on antibiotics began to apply toward all instances of their use, and still holds up half a century later.
But surely there must be some medical complications associated with mixing antibiotics and booze, otherwise the myth wouldn't stick around for so long, right? Or is it one of those "just to be safe" recommendations?
Alcohol doesn't make antibiotics themselves any less effective
A lot of people think drinking on antibiotics will render them useless in fighting off whatever bacteria they're trying to combat; 81% of patients surveyed in a London clinic thought that was the case. Turns out, antibiotics will still do their thing even if alcohol is introduced to the body -- it just might exacerbate any sick symptoms you may have.
"While antibiotics may not interfere with the absorption or action of most antibiotics, you're nuts to do this," says Dr. John Swartzberg, chair of Berkeley Wellness' editorial board. "If you're sick enough to be on antibiotics, you're too sick to consume alcohol."
Dr. Swartzberg says alcohol impairs your immune response, which you need in good working order to fight off an infection. Drinking also interferes with your ability to have a good night's sleep, your energy levels, and your ability to stay hydrated; all important factors needed for your body to get better. "Antibiotics help us deal with infections; our immune system cures us," he says. So even if the antibiotics themselves are still working, your body may not be able to fight off an infection at 100%.
Alcohol may make side effects more severe
Although antibiotics' effectiveness should still be intact, some side effects might be magnified when mixed with alcohol. Like most other drug intolerances, side effects of antibiotics can include nausea, dizziness, lightheadedness, and diarrhea. And as anyone who has enjoyed a few adult beverages in a row knows, those side effects are also associated with alcohol consumption, so combining the two can make everything worse.
If you experience a rash or itching, those are allergic reactions your body is having to the antibiotics not related to an alcohol interaction. Although those symptoms usually clear up on their own, you may want to see a doctor just in case. More severe allergic reactions include difficulty breathing and shock, which require emergency care.
Certain antibiotics require total abstinence from alcohol
You're going to have to call it quits on the booze for a while if you're prescribed any of these: metronidazole (Flagyl), tinidazole (Tindamax), and trimethoprim-sulfamethoxazole (Bactrim, Septra). Metronidazole and tinidazole are almost guaranteed to have a bad reaction with alcohol, including nausea, vomiting, and rapid heart rate. The evidence for mixing trimethoprim-sulfamethoxazole and alcohol isn't as definitive, Dr. Swartzberg says, but it's probably best to avoid combining the two just in case.
Overall: it's not advised, but you can do it (within reason)
If you're taking an antibiotic regularly, like for acne or rosacea, then Dr. Swartzberg says drinking (moderately) on it is fine, as long as it's not one of the problematic ones listed above; just make sure you discuss with your doctor first. When someone has an infection, however, it's best to stay sober until your dosage is up -- it's usually only for a few days anyway -- to speed up the recovery process.
One major issue is people who are too worried about possible drug interactions, so they'll skip a dose (or several) of antibiotics in favor of drinking a beer. Taking antibiotics improperly like this may lead to antibiotic resistance, which is becoming a pretty alarming issue. But if you really can't say no to happy hour, then a drink or two shouldn't make you incredibly sick or give you gnarly side effects (if you experience signs of a drug allergy, such as a rash or vomiting, then call your doctor).
The biggest problem now might be coming up with another excuse to tell your friends why you're not drinking.