diacetylmorphine ( heroin ), morphine acts directly on the central nervous system (CNS) to relieve pain . Morphine has a high potential for addiction ; tolerance and psychological dependence develop rapidly, although physiological dependence may take several months to develop. Read more... Edit at Wikipedia... Other names (5a,6a)-7,8-Didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol; (5alpha,6alpha)-17-Methyl-7,8-didehydro-4,5-epoxymorphinan-3,6-diol; (5alpha,6alpha)-7,8-Didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol; (5alpha,6alpha,9alpha)-17-methyl-7,8-didehydro-4,5-epoxymorphinan-3,6-diol;