Influence of CYP2D6 activity on the pharmacokinetics and pharmacodynamics of a single 20 mg dose of ibogaine in healthy volunteers.
Paul Glue, Helen Winter, Kira Garbe, Hannah Jakobi, Alexander Lyudin, Zoe Lenagh-Glue, Cheung-Tak Hung
Journal of clinical pharmacology June 1, 2015 DOI: 10.1002/jcph.471 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 21 |
| Population | Healthy subjects |
| Interventions | Ibogaine Paroxetine |
| Dose | 20 mg |
| Duration | 168 hours |
| Topics | Ibogaine |
| Keywords | Paroxetine Pharmacodynamics Ibogaine pharmacokinetics Cyp2d6 enzyme activity Drug safety optimization |
| Citations | 39 |
| Key findings | Inhibiting CYP2D6 with paroxetine approximately doubled exposure to the active moiety of ibogaine, suggesting dose reduction is prudent for CYP2D6 poor metabolizers. |
Abstract
Conversion of ibogaine to its active metabolite noribogaine appears to be mediated primarily by CYP2D6. We compared 168 hours pharmacokinetic profiles of both analytes after a single oral 20 mg dose of ibogaine in 21 healthy subjects who had been pretreated for 6 days with placebo or the CYP2D6 inhibitor paroxetine. In placebo-pretreated subjects, ibogaine was rapidly converted to noribogaine. Median peak noribogaine concentrations occurred at 4 hours. Compared with placebo-pretreated subjects, paroxetine-pretreated subjects had rapid (Tmax = 1.5 hours) and substantial absorption of ibogaine, with detectable levels out to 72 hours, and an elimination half-life of 10.2 hours. In this group, ibogaine was also rapidly converted to noribogaine with a median Tmax of 3 hours. Extent of noribogaine exposure was similar in both groups. CYP2D6 phenotype was robustly correlated with ibogaine AUC0-t (r = 0.82) and Cmax (r = 0.77). Active moiety (ibogaine plus noribogaine) exposure was ∼2-fold higher in paroxetine-pretreated subjects. Single 20 mg ibogaine doses were safe and well tolerated in all subjects. The doubling of exposure to active moiety in subjects with reduced CYP2D6 activity suggests it may be prudent to genotype patients awaiting ibogaine treatment, and to at least halve the intended dose of ibogaine in CYP2D6 poor metabolizers.