Drug Interactions between Bactrim and cefpodoxime

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of cefpodoxime proxetil tablets. Following a 200 mg dose taken with food, the extent of absorption (mean AUC) was 21% to 33% higher and the mean peak plasma concentration (Cmax) 19% higher than under fasting conditions. Time to peak concentration (Tmax) was not significantly different between fed and fasted states. On the contrary, when a 200 mg dose of the suspension was taken with food, the mean AUC and Cmax were not significantly different than those under fasting conditions, although the rate of absorption was slower with food (48% increase in Tmax ).

MANAGEMENT: To ensure maximal oral absorption, cefpodoxime proxetil tablets should be administered with or immediately after a meal.

MONITOR: Two cases have been reported in which patients on sulfamethoxazole-trimethoprim therapy, after consuming beer, reported flushing, heart palpitations, dyspnea, headache, and nausea (disulfiram - alcohol type reactions). First-generation sulfonylureas have been reported to cause facial flushing when administered with alcohol by inhibiting acetaldehyde dehydrogenase and subsequently causing acetaldehyde accumulation. Since sulfamethoxazole is chemically related to first-generation sulfonylureas, a disulfiram-like reaction with products containing sulfamethoxazole is theoretically possible. However, pharmacokinetic/pharmacodynamic data are lacking and in addition, the two reported cases cannot be clearly attributed to the concomitant use of sulfamethoxazole-trimethoprim and alcohol.

MANAGEMENT: Patients should be alerted to the potential for this interaction and although the risk for this interaction is minimal, caution is recommended while taking sulfamethoxazole-trimethoprim concomitantly with alcohol.