The pharmacokinetics and metabolism of ciclazindol, a potential anti-depressant drug, have been studied after oral administration of the compound to male and female volunteers. 2. The mean +/- S.E. mean maximum plasma concentration of the unchanged drug was 422 +/- 31 ng/ml. This level was seen between 2 and 4 h after dosing. 3. Elimination of the ciclazindol from plasma was apparently monexponential with a half-life of approximately 32 h. A large proportion of the drug-related substances in the plasma was unchanged drug. 4. Excretion of radioactivity took place predominantly via the renal route, less than 15% of the dose being recovered in the faeces. The urinary elimination process was apparently monoexponential with a half-life of 28 h. 5. Daily dosing with ciclazindol for 3 weeks did not appear to induce the enzymes of its own metabolism.
