Modulation of morphine-induced antinociception by ibogaine and noribogaine.
Brain research – November 25, 1996
Source: PubMed
Summary
Ibogaine significantly alters morphine's pain-relieving effects in a rat study. When given 19 hours prior to morphine, a dose of 40 mg/kg ibogaine reduced morphine's effectiveness. However, when administered together, doses of ibogaine (1-40 mg/kg) enhanced morphine's pain relief. Notably, noribogaine, ibogaine's active metabolite at 40 mg/kg, also boosted morphine's effects but did not inhibit them when given beforehand. These findings suggest ibogaine may enhance morphine's analgesic properties while also highlighting complex interactions between these substances.
Abstract
The potential modulation of morphine antinociception by the putative anti-addictive agent ibogaine and its active metabolite (noribogaine) was investigated in rats with the radiant heat tail-flick test. Ibogaine pretreatment (40 mg/kg, i.p., 19 h) significantly decreased morphine (4 mg/kg, s.c.) antinociception, with no effects in the absence of morphine. However, co-administration of ibogaine (1-40 mg/kg, i.p.) and morphine (4 mg/kg, s.c.) exhibited a dose-dependent enhancement of morphine antinociception. Co-administration of noribogaine (40 mg/kg, i.p.) and morphine also resulted in an increase in morphine antinociception, while noribogaine pretreatment (19 h) had no effect on morphine antinociception. The results show that ibogaine acutely potentiates morphine antinociception and that noribogaine could be the active metabolite responsible for this effect. However, the inhibitory effects of a 19 h ibogaine pretreatment, which resemble ibogaine-induced inhibition of morphine's stimulant properties, cannot be accounted for by noribogaine.