Route of cocaine administration: patterns of use and problems among a Brazilian sample.

Route of administration has important implications for the understanding of drug addiction and related-problems. This cross-sectional study investigates patterns of consumption and cocaine-related problems among snorting and crack cocaine users in São Paulo and outlines changes in route of cocaine administration in Brazil between 1980-1997. Crack cocaine users had more social and health problems and higher involvement in crime than intranasal users. These problems, compounded by the larger doses being used and their greater involvement in prostitution, place crack cocaine users at higher risk from HIV infection and other sexually transmitted diseases as well as other physical risks.