The aims of the study was to determine drug resistance rates in 30 tuberculosis patients previously have been treated with streptomycin (SM), isoniazide (INH), ethabutol (E) and rifampicin (R) in Pirngadi Hospital, Medan. Ninety-six percent of these patients showed resistance to one or more of the following 4 drugs SM, INH, E and RF. Resistance to E was encountered most (83.33 percent), followe…