APOMORPHINE AND DIPHASIC DYSKINESIA

We report on three observations of parkinsonian patients with levodopa -induced diphasic dyskinesias, who received subcutaneous apomorphine t o reduce the duration of abnormal movements. Apomorphine was effective in reducing the duration of diphasic dyskinesias at doses higher than the threshold doses necessary to induce an ''on'' phase (mean increas e: 43%). However, after a few months of treatment, apomorphine was ine ffective in stopping abnormal movements, even when doses were increase d. In two patients, apomorphine remained effective in the morning, but increased the intensity of the dyskinesias in the afternoon. Acute di urnal variations of the pharmacodynamic striatal response are suggeste d explanation for these clinical observations.