Elantrine in the treatment of parkinsonism.

A new drug, elantrine, blocks the tremorogenic effect of exotremorine, nicotine and harmine in animals. A double blind study compared elantrine with trinhexyphenidyl and against a baseline placebo period, in a group of Parkinson patients. Both, elantrine and trihexyphenidyl treatment, reduced tremor scores at the conclusion of the respective treatment periods, but closer analysis revealed 65% of patients receiving elantrine had lower tremor scores compared to their baseline (placebo) opposed to only 53% receiving trihexyphenidyl. Both drugs produced aequal effect on rigidity. Another group of Parkinson patients receiving clinically optimal doses of L-dopa were treated with either elantrine or placebo, in blind fashion. Analysis of both tremor and rigidity revealed mean scores significantly lower (P less than 0.05) for those patients receiving elantrine than placebo. Also, there was a statistically significant difference in average total symptom scores favoring the elantrine group. Significant improvement with elantrine administration began after the second week for rigidity and after the third week for tremor. Elantrine is a safe, well tolerated agent which is effective alone in the treatment of parkinsonism but significantly enhances the effectiveness of L-dopa, particularly with respect to tremor and rigidity.