Serum concentration of co-trimoxazole during a high-dosage regimen.

Objectives: Sulfamethoxazole and trimethoprim have been used for decades, yet high dosages are rarely reported. We aimed to measure blood concentrations of both molecules in this situation.

Methods: Between 2002 and 2010, 22 patients received two tablets of co-trimoxazole three times a day, equivalent to a daily dosage of 2400 mg of sulfamethoxazole and 480 mg of trimethoprim.