Melatonin and Parkinsonism

Abstract

<h3>To the Editor.—</h3> Lerner discovered melatonin (<i>N</i>-Acetyl-5-methoxytryptamine)¹and showed that this pineal hormone can induce sedation in man.²This agent antagonizes the darkening of the skin and, therefore, perhaps also some other action of melanophore-stimulating hormone (βMSH).³Since injections of βMSH had aggravated the tremor of parkinsonism,⁴we had administered this antagonist of βMSH to a patient but induced only a diminution of tremor.³Others, however, reported impressive improvement of several symptoms of parkinsonism⁵at a time when we had reversed the adventitious movements caused by levodopa [3-(3, 4-dihydroxyphenyl)-L-alanine] with melatonin in experimental animals.⁶We conducted therefore a single-blind study in patients with parkinsonism who received either melatonin alone or melatonin plus levodopa, which had caused intermittent adventitious movements.⁷ The inpatients listed in the Table and all of the outpatients had idiopathic parkinsonism except patient 11 who had postencephalitic disease. Among