ENDOCARDITIS IN INJECTION-DRUG USERS

Injection drug use is an important risk factor for endocarditis. The c linical manifestations of endocarditis associated with injection drug use differ from those in persons who do not use drugs. Endocarditis in drug users more often affects the right side of the heart and present s with fever and pulmonary emboli rather than left-sided emboli. Blood cultures and echocardiography are the mainstay of diagnosis; these te sts are particularly helpful in identification of endocarditis associa ted with injection drug use because of the high frequency of right-sid ed valvular involvement and the low incidence of culture-negative endo carditis in this population. Since staphylococcal species are the domi nant causative organism, penicillin and an aminoglycoside are the trea tments of choice. Injection drug users with left-sided endocarditis or with symptomatic human immunodeficiency virus infection have poor pro gnoses.