MinorFluoroquinolone antibacterials×Estrogens. Natural and semisynthetic estrogens, plain
Updated · Methodology
Mechanism
The historical theory of reduced combined oral contraceptive efficacy via gut flora suppression is rejected by meta-analyses. Ciprofloxacin does not induce CYP3A4 and does not affect ethinylestradiol metabolism.
Symptoms
The combination usually causes no specific symptoms. Each drug's individual side effects remain.
Management
Additional contraception during short ciprofloxacin courses is not needed. The old "use a barrier method for the whole cycle" advice is outdated.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
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