antibiotic trimethoprim/sulfamethoxazole YH, YL TMP/SMZ TMP/SMZ in a fixed ratio of 1:5 (80 mg TMP/400 mg SMZ) is more active in vitro against Brucella species than either drug alone. Although initial studies with TMP/ SMZ reported good results, prospective, controlled, comparative trials demonstrated that the drug was associated with an unacceptably high rate of relapse. Consequently, TMP/SMZ should always be used in combination with another agent, such as doxycycline, rifampicin or streptomycin. (http://www.who.int/csr/resources/publications/Brucellosis.pdf p38) co-trimoxazole