A single injection of ibogaine (40 mg/kg) in rats significantly reduced cocaine self-administration for more than 48 hours. Because ibogaine's half-life is short, one or more of its active metabolites may be responsible. Repeated ibogaine doses over three consecutive days also decreased cocaine intake, and the strongest effect came from weekly injections for three weeks. These findings suggest ibogaine or its metabolites can produce a long-lasting interruption of cocaine dependence, consistent with uncontrolled clinical observations.
In morphine-dependent rats, norharman (20 mg/kg) and ibogaine (40 mg/kg) each reduced the severity of withdrawal symptoms triggered by naloxone (4 mg/kg). Specific signs including teeth-chattering, chewing, penile licking, and diarrhea were lessened by both compounds. Norharman additionally decreased withdrawal-related grooming and rearing. The findings suggest that both norharman and ibogaine can inhibit opioid withdrawal syndrome.