Laboratory and clinical studies on sulfamethoxazole (SMX) -trimethoprim (TMP) combination have been performed. Laboratory studies are based on the determination of minimal inhibitory concentrations (MICs) of SMX and TMP, alone and in combination ratio of 20 : 1 (SMX : TMP) in 33 clinically isolated strains of Staphylococcus aureus. MICs of the combination of SMX and TMP ranged from 0.4-12.5 mcg/ ml, which were lower by 2-3 folds than those of SMX alone and higher by 1-2 folds than those of TMP alone.
A clinical trial of SMX-TMP combination product included 12 patients with bacterial infections in the field of internal medicine. The effective response was obtained in 83.3% of the clinical material. This preparation appeared to have antipyretic activity as evidenced by defervescence in 5 of 6 patients with high-fever of unknown origin. Obvious clinical improvement followed a little later than the beginning of defervescence. No untoward clinical reactions to the medication were recorded, and examinations of blood counts, liver and renal function did not reveal anormalities ascribable to the drug administration. Because of its unique mechanism of action, this preparation appears to be a useful addition to the armamentrium of chemotherapeutic agent. The prompt antipyretic effect appears to warrant further studies.
