A single large dose of trimethoprim-sulfamethoxazole fails to cure gonococcal urethritis in men.
In a single-blind study, 50 men who had acute gonococcal urethritis were treated with a single oral dose of either 720 mg trimethoprim (TMP) plus 3,600 mg sulfamethoxazole (SMZ) or 3.5 g ampicillin plus 1 g probenecid. Isolates of Neisseria gonorrhoeae were tested for in-vitro susceptibility to the chemotherapeutic agents administered by agar-dilution and disk-diffusion methods, and results were correlated with cure or failure to cure as determined bacteriologically. Among patients returning for follow up, the cure rate after TMP/SMZ was 69%. Cure was predictable when the isolates of N. gonorrhoeae were inhibited by < or = 0.63/11.87 micrograms/ml of TMP/SMZ (fixed ratio, 1:19) or when the zones of inhibition were > or = 23 mm; failure was predictable when > or = 1.25/23.75 micrograms/ml of TMP/SMZ was necessary for inhibition and when zones of inhibition were < or = 21 mm (P < 0.02). The cure rate after therapy with ampicillin was 100%, a rate significantly higher than that found after TMP/SMZ (P < 0.02); all isolates were inhibited by < or = 0.16 microgram/ml of ampicillin. Adverse reactions were not seen after either TMP/SMZ or ampicillin.
D000328:Adult; D000667:Ampicillin / Q000008:administration & dosage / Q000494:pharmacology; D000892:Anti-Infective Agents, Urinary / Q000008:administration & dosage* / Q000494:pharmacology; D004359:Drug Therapy, Combination; D006069:Gonorrhea / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000187:drug effects; D011339:Probenecid / Q000008:administration & dosage; D012076:Renal Agents / Q000008:administration & dosage; D016037:Single-Blind Method; D016896:Treatment Outcome; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage* / Q000494:pharmacology; D014526:Urethritis / Q000188:drug therapy*