Will Antibiotics Decrease the Effectiveness of My Birth Control Pill?


I am currently on the pill and had sex two days before taking antibiotics. Will antibiotics decrease the effectiveness of oral contraceptives? Should I use condoms just to be safe?


A study in the Journal of the American Academy of Dermatology found that the following antibiotics do not affect the use of hormonal contraceptives: ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline. The only antibiotic that has been shown to interfere with oral contraction is rifampicin (Rifadin). Taking hormonal contraceptives with rifampicin reduces the contraceptive’s effectiveness, which could result in unintended pregnancy or breakthrough bleeding.

If you have been prescribed rifampicin it is a good idea to use other methods of contraception, such as a condom. Another alternative is to talk to your health care provider about other forms of hormonal contraception that are unaffected by antibiotic use, such as progestogen-only injection or intrauterine device (IUD). You don’t typically need to use additional contraception if you’re taking antibiotics other than rifampicin.

Click here to learn more about antibiotics and birth control pill interactions.

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