CHOICE BETWEEN MONEY AND INTRANASAL HEROIN IN MORPHINE-MAINTAINED HUMANS

Five morphine-maintained individuals participated in an inpatient stud y evaluating the effects of a monetary alternative ($10, $20, $40) on intranasal (i.n.) heroin (placebo, 12.5, 25, 50, 100 mg) self-administ ration, using a procedure in which subjects chose between money and he roin. Each money amount was tested in combination with each heroin dos e. Subjects responded under a progressive-ratio schedule (PR 50, 100,. .., 2800); the PR value increased independently for each option. Subje ctive, performance, and physiological effects were also measured durin g each session. Heroin breakpoint values increased in a dose-related m anner, relative to placebo, when $10 or $20 was available. In contrast , only the highest dose produced a heroin breakpoint value that was si gnificantly different from placebo when $40 was available. Heroin also produced dose-related increases in several ratings of drug effect, in cluding ''I feel...'' ''a good drug effect'', ''high'', ''mellow'', an d ''stimulated''. These effects were not significantly affected by the alternative money condition. These results demonstrated: (1) the dose -related reinforcing effects of i.n. heroin in opioid-dependent indivi duals; (2) that i.n. heroin self-administration can be modified by the availability of an alternative reinforcer (i.e. money); and (3) that self-reported drug effects can be differentiated from drug self-admini stration.