The effect of L-5-hydroxytryptophan on self-mutilatin in Lesch-Nyhan disease: a negative report.

Four patients with Lesch-Nyhan disease were treated with L-5-hydroxytryptophan, alone, or in combination with carbidopa, and their effect on self-mutilatory behavior was compared to that observed during periods in which placebo was administered. Observation periods were carefully standardized because of the ease with which patient-observer interactions can influence the behavior of the Lesch-Nyhan patient. The dosage level was sufficient to produce undesirable side-effects (diarrhea and vomiting). No effect on self-mutilation was observed under test conditions in the hospital or in the natural environment of the home. These results contrast with previous beneficial effects reported by others.