Interactions between ampicillin and Aralen hydrochloride (chloroquine)
ampicillin and chloroquine (Moderate Drug-Drug)
ADJUST DOSING INTERVAL: The concomitant administration of chloroquine may delay as well as decrease the gastrointestinal absorption of ampicillin. The exact mechanism of interaction is unknown but may involve slowing of gastric emptying and enhancement of gut motility induced by chloroquine. In seven healthy volunteers, coadministration of a single 1 gram oral dose each of chloroquine and ampicillin resulted in an approximately 30% decrease in both the rate and extent of ampicillin absorption compared to administration of ampicillin alone. In contrast, the bioavailability of ampicillin from the prodrug, bacampicillin, is reportedly not affected by chloroquine.
MANAGEMENT: To avoid potentially subtherapeutic plasma concentrations of ampicillin during coadministration with chloroquine, the drugs should probably be administered at least 2 hours apart.
