Therapeutic potential of cyclopheron was evaluated as exemplified by the treatment of patients with chronic brucellosis. Positive clinical dynamics during combined treatment including cyclopheron is apparent as reduced duration of intoxication and inflammation, improved quality of life, decreased frequency of exacerbation of the infectious process and development of intercurrent diseases. These effects are shown to be due to immunomodulating activity of cyclopheron and suppression of lipid peroxidation. Also, the drug increases activity of antioxidants, decreases the levels of proinflammatory (and to a lesser degree of anti-inflammatory) cytokines.