TISSUE DISTRIBUTION OF IBOGAINE AFTER INTRAPERITONEAL AND SUBCUTANEOUS ADMINISTRATION

The distribution of the putative anti-addictive substance ibogaine was measured in plasma, brain, kidney, liver and fat after ip and sc admi nistration in rats. One hr after ip dosing (40 mg/kg), drug levels ran ged from 106 ng/ml (plasma) to 11,308 ng/g (fat), with significantly h igher values after sc administration of the same dose. Drug levels wer e 10-20 fold lower 12 hr after the same dose. These results suggest th at: 1) ibogaine is subject to a substantial ''first pass'' effect afte r ip dosing, demonstrated by higher drug levels following the sc route , 2) ibogaine shows a large accumulation in adipose tissue, consistent with its lipophilic nature, and 3) persistence of the drug in fat may contribute to a long duration of action.