[Effect of a synthetic analog of enkephalin on the choreic syndrome]

A cross-over, double-blind intravenous administration of a single dose of FK 33-824, a rigid analog of enkephalin, was performed in 12 choreic patients (0,5 mg in 6 patients, 2 mg in 6 patients). The number of abnormal involuntary movements per minute and their amplitude was not altered after FK 33-824 when compared to placebo administration. This result however does not exclude the possibility of a functional interaction between Met-enkephalinergic and dopaminergic systems in the human brain.