title: Use of trimethoprim-sulfamethoxazole for treatment of infections due to Nocardia.
abstract: Trimethoprim-sulfamethoxazole (TMP-SMZ) was used for treatment of 34 patients with pulmonary or cutaneous nocardiosis. Of nine patients with primary cutaneous disease, eight had rapid resolution of their infection after short-term therapy and none have relapsed after a follow-up of more than six months. The 25 patients with pulmonary nocardiosis had a good clinical response, but three of five (60%) who completed less than three months of therapy relapsed within four weeks. Of the 10 patients who completed four to six months of therapy, only one (10%) relapsed and this relapse was due to drug resistance. By the method of serial dilution in agar, 96% of 59 isolates of Nocardia had MICs of SMZ of less than 25 micrograms/ml. Fewer than 20% were susceptible to 2.5 micrograms of TMP/ml. Synergy between TMP and SMZ was usually present with ratios of TMP to SMZ of 1:5, 1:1, or 5:1, but was less common at a ratio of 1:20. Disk susceptibility testing was easy to perform and readily separated sensitive from resistant strains. TMP-SMZ is highly effective for the treatment of nocardiosis, but the question of whether it is more effective clinically than a sulfonamide alone remains unanswered.
mesh_terms: D000328:Adult; D000368:Aged; D002675:Child, Preschool; D004338:Drug Combinations / Q000627:therapeutic use; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009617:Nocardia Infections / Q000188:drug therapy* / Q000382:microbiology; D011014:Pneumonia / Q000188:drug therapy; D013420:Sulfamethoxazole / Q000494:pharmacology / Q000627:therapeutic use*; D014295:Trimethoprim / Q000494:pharmacology / Q000627:therapeutic use*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination
chemical_list: D004338:Drug Combinations; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D014295:Trimethoprim; D013420:Sulfamethoxazole