Abuse of antibiotics by abusers of parenteral heroin or cocaine

We studied antibiotic intake in 197 abusers of alcohol, sedatives, or parenteral heroin or cocaine. Thirteen patients, all abusers of parenteral heroin or cocaine, had taken antibiotics without prescription, obtained from friends, from old prescriptions, or by purchase on the street. Past or present street purchase of antibiotics was noted in 27 patients and was more common (P less than .02) in parenteral substance abusers. Four parenteral substance abusers had infection or colonization with methicillin-resistant Staphylococcus aureus, and three of them had purchased antibiotics on the street before the present or a recent past hospitalization. Physicians treating abusers of parenteral heroin or cocaine should be aware that such patients may be taking antibiotics without medical supervision. This practice may be an important factor in the development and spread of methicillin-resistant S aureus.