Prior morphine exposure enhances ibogaine antagonism of morphine-induced locomotor stimulation.
Psychopharmacology – October 01, 1995
Source: PubMed
Summary
Ibogaine may significantly reduce morphine-induced locomotor stimulation in rats previously exposed to morphine. In a study involving female Sprague-Dawley rats, those pretreated with morphine (10-30 mg/kg) showed a notable decrease in locomotion after receiving ibogaine (40 mg/kg), compared to saline-pretreated rats. This effect was consistent across various dosages of ibogaine (5-60 mg/kg) and morphine (2.5-5 mg/kg). Findings suggest that prior opioid exposure influences the effectiveness of ibogaine, highlighting the complexity of treating opioid addiction based on individual histories.
Abstract
Ibogaine is currently being investigated for its potential use as an anti-addictive agent. In the present study we sought to determine whether prior morphine exposure influences the ability of ibogaine to inhibit morphine-induced locomotor stimulation. Female Sprague-Dawley rats were pretreated once a day for 1-4 days with morphine (5, 10, 20 or 30 mg/kg, i.p.) or saline and then received ibogaine (40 mg/kg, i.p.) 5 h after the last morphine pretreatment dose. Compared to rats pretreated with saline, rats pretreated with morphine (10, 20 or 30 mg/kg, i.p.) before ibogaine (40 mg/kg, i.p.) showed a significant reduction in morphine-induced (5 mg/kg, i.p.) locomotor stimulation when tested 29 h after ibogaine administration. Furthermore, this effect was apparent over a range of ibogaine (5-60 mg/kg, i.p.) and morphine test (2.5-5 mg/kg, i.p.) dosages. Doses of ibogaine (5 and 10 mg/kg, i.p.) which alone were inactive inhibited morphine-induced locomotor activity when rats had been pretreated with morphine. These results, showing that morphine pre-exposure affects ibogaine activity, suggest that variable histories of opioid exposure might account for individual differences in the efficacy of ibogaine to inhibit opioid addiction.