Effects of ibogaine on acute signs of morphine withdrawal in rats: independence from tremor.

Ibogaine, a compound reported to suppress narcotic withdrawal in humans, was tested in morphine-dependent rats. Rats received morphine for five days, then ibogaine (20, 40, or 80 mg/kg) or saline 30 minutes before naltrexone-precipitated withdrawal. Doses of 40 and 80 mg/kg significantly reduced four withdrawal signs: wet-dog shakes, grooming, teeth chattering, and diarrhea. Three other signs—weight loss, burying, and flinching—were unaffected. Ibogaine caused head and body tremors lasting 2-3 hours, which might have interfered with withdrawal expression. In a second experiment, ibogaine given 4 hours before naltrexone, when tremors were absent, still significantly reduced the same four withdrawal signs, indicating a genuine anti-withdrawal effect.

Study at a glance

Abstract

Because of the claim that ibogaine suppresses the symptoms of "narcotic withdrawal" in humans, the effect of ibogaine on naltrexone-precipitated withdrawal signs in morphine-dependent rats was assessed. Morphine was administered subcutaneously through implanted silicone reservoirs for 5 days. Ibogaine (20, 40 or 80 mg/kg, i.p.) or saline was administered 30 min prior to challenge with naltrexone (1 mg/kg, i.p.) and withdrawal signs were counted for the following 2 hr. Ibogaine (40 and 80 mg/kg) significantly reduced the occurrence of four signs (wet-dog shakes, grooming, teeth chattering and diarrhea) during naltrexone-precipitated withdrawal; three other signs (weight loss, burying and flinching) were unaffected. Ibogaine induces head and body tremors lasting for 2-3 hr and the tremors might have interfered with the expression of opioid withdrawal. To examine this issue, another experiment was conducted in which ibogaine (40 mg/kg) or saline was administered 4 hr prior to challenge with naltrexone. Although there was a complete absence of tremors, ibogaine still significantly reduced the occurrence of the same four signs of withdrawal.