aminoglycoside streptomycin Streptomycin (1 g/day intramuscularly) administered for two to three weeks has long been the aminoglycoside of choice when used in combination with tetracycline or doxycycline. Although synergy between the two drugs is difficult to prove using routine in vitro assays, bacterial killing studies have shown that Brucella species undergo a more rapid rate of killing by the combination than by either drug alone. (http://www.who.int/csr/resources/publications/Brucellosis.pdf p37)