Should You Take Antibiotics with Birth Control Pills?

The birth control pill is one of the most effective forms of contraception available to women, but there are certain factors that can make oral contraceptives less effective. Of course, forgetting to take your pill on a each day is one important factor, but what about medications? You hear so much about drug interactions and the effects that one medication can have on another. One of the most commonly used medications is antibiotics. Is it safe to take the birth control pill with antibiotics?

Are all antibiotics equal?

It was originally thought that taking the birth control pill with any antibiotic was risky in terms of contraceptive effectiveness. Women were advised to use an alternative form of birth control while taking any prescription antibiotic. The most recent studies suggest that only two antibiotics are definitively known to reduce the effectiveness of the birth control pill. These are the antibiotics Rifampin, used to treat tuberculosis and Griseofulvin, used to treat some fungal infections. These particular antibiotics appear to increase levels of estrogen in the bloodstream which can decrease the effectiveness of the birth control pill.

What about taking birth control pills with common antibiotics such as Penicillin?

Although there have been no large studies demonstrating that taking the birth control pill with antibiotics such as Penicillin and Sulfa, among others, decreases the effectiveness of the birth control pill, it’s still theoretically possible, although most experts don’t believe it’s a threat to most women. Because estrogen is metabolized by bacteria in the gut and antibiotics alter the number and types of bacteria, it’s possible that some reduction in effectiveness could occur in a small subset of women.

What’s the bottom line?

Because of the uncertainty associated with taking the birth control pill with antibiotics, most doctors recommend using another form of birth control pill during the time you’re on antibiotics as well as for at least a week after you come off of them. The problem arises if you’re taking a low dose of antibiotics longer term, such as for urinary tract prevention or acne. In these cases, the bacteria in the gut generally adapt after a period of time and the birth control pill will resume its effectiveness if it’s affected at all by the antibiotic. In these cases, you should use another form of contraceptive for three weeks until this adaptation takes place.

As always, talk to your doctor about what’s best for your particular situation.