18-MC reduces methamphetamine and nicotine self-administration in rats

In previous studies, 18-methoxycoronaridine (18-MC), a novel iboga alkaloid congener, has been found to decrease the intravenous self-administration o f morphine and cocaine in rats. In the present study, 18-MC (1-40 mg/kg, i. p.) dose-dependently decreased the i.v. self-administration of methamphetam ine and nicotine. As in the previous studies, drug self-administration was reduced for greater than or equal to 24 h after the highest dose of 18-MC. A comparison of 18-MC's interactions with all four drugs of abuse studied s o far indicated that 18-MC is least effective in decreasing methamphetamine self-administration and most potent in decreasing nicotine self-administra tion. The results suggest that a nicotinic antagonist action of 18-MC contr ibutes to its putative anti-addictive efficacy. NeuroReport 11:2013-2015 (C ) 2000 Lippincott Williams & Wilkins.