Ibogamine (20-40 mg/kg), harmaline (10-40 mg/kg) and desethycoronaridine (10-40 mg/kg) were obviously tremorigenic for 3-4 h and no attempt was made to compare these drugs quantitatively. However, visual observations and videotape recordings of 18-methoxycoronaridine (40 mg/kg) and both R- and S-enantiomers of both ibogamine (40 mg/kg) and coronaridine (40 mg/kg) indicated very little if any tremorigenic activity. The effects of these latter drugs were therefore assessed using the automated testing procedure developed to quantitate tremors. Ibogains (40 mg/kg) and saline (1 ml/kg) were used as positive and negative controls, respectively. While ibogaine produced a significant increase in movements indicative of tremors, the 18-methoxycoronaridine and the ibogamine and coronaridine enantiomers had no effects that differed significantly from the effects of saline.
