d000249 d001047 d002444 d000231 d000232 d000237 d000238 d000239 d000240 d000355 d000850 d001046 d001764 d001851 d001923 d001966 d001967 d001968 d001969 d001970 d001971 d003040 Patients stabilized on an oral anti-coagulant are at a higher risk of developing bleeding complications if large IV doses of penicillin are also administered. This interaction may be due to a combined inhibition of ADP-induced platelet aggregation. This interaction is dose-dependent. Patients receiving large doses of an IV penicillin should have their coagulation status monitored more closely. The dose of one or both medications should be adjusted accordingly, or an alternate antibiotic selected. Davis RLWarfarin-nafcillin interaction. J Pediatr. 1991;118:300 Brown MAInteraction of penicillin-G and warfarin? Can J Hosp Pharm. 1979;32:18 Krstenansky PMClin Pharm. 1987;6:804 Shovick VADICP, Ann Pharmacother. 1991;25:598