Interaction between ciprofloxacin and rifampin.

OBJECTIVE: To discuss the necessity of dose adjustment for ciprofloxacin or rifampin during their concurrent use. DATA SOURCES: A MEDLINE search (1966-December 1998) was completed using key terms rifampin and fluoroquinolone. English-language journals were considered. DATA SYNTHESIS: Studies in elderly patients after 14 days of therapy with oral ciprofloxacin and rifampin did not demonstrate significant differences in the pharmacokinetics of ciprofloxacin as compared with those in patients receiving ciprofloxacin alone. Similar results were found in intravenous drug abusers. In comparison to the pharmacokinetics of both ciprofloxacin and rifampin when given alone, the serum bactericidal activity of rifampin, when given with ciprofloxacin in healthy elderly volunteers, was reduced but still evident. Ciprofloxacin pharmacodynamics were not significantly altered. Serum bacterial titers of ciprofloxacin and pefloxacin increased twofold when given with rifampin, although their clinical significance is unknown. RECOMMENDATION: No strong evidence of a significant interaction exists to support dose adjustment for ciprofloxacin or rifampin during their concurrent use.