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 of 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 methamphetamine and nicotine. As in the previous studies, drug self-administration was reduced for > or = 24 h after the highest dose of 18-MC. A comparison of 18-MC's interactions with all four drugs of abuse studied so far indicated that 18-MC is least effective in decreasing methamphetamine self-administration and most potent in decreasing nicotine self-administration. The results suggest that a nicotinic antagonist action of 18-MC contributes to its putative anti-addictive efficacy.