Is this the final word on antibiotics and contraception?

There is no reason for women to employ backup contraception when taking antibiotics unless they are taking rifamycin-like drugs, a systematic review of 29 studies confirms.

Results from the study show concomitant antibiotic use (including penicillins, cephalosporins, quinolones, tetracyclines, macrolides, trimethoprim sulfamethoxazole, metronidazole, dapsone, and isoniazid/streptomycin) was not associated with changes in pregnancy rates or ovulation.

There was also little evidence of unscheduled uterine bleeding or significant declines in serum progestin levels in women