antibiotic tetracycline Tetracycline (500 mg every six hours orally) administered for at least six weeks has long been the standard treatment of human brucellosis. Doxycycline (a long acting tetracycline analogue) is now the preferred drug because it can be given once or twice daily, and is associated with fewer gastrointestinal side effects than tetracycline. Doxycycline is given in a dose of 100 mg every 12 hours orally and is administered for a period of six weeks. (http://www.who.int/csr/resources/publications/Brucellosis.pdf p36) YH,YL