An open clinical trial of fenfluramine in chronic schizophrenia: a pilot study.

The reports of hyperserotonaemia in chronic schizophrenics and the indications that fenfluramine, a serotonin-releasing drug, may be of therapeutic value in hyperserotonaemic autistic children, were the rationale for this clinical trial. Fenfluramine was administered to 4 treatment-resistant chronic schizophrenic in-patients. They were studied for 14 weeks: 2 baseline weeks, 8 on fenfluramine (maximal dose 120 mg/day for 4 weeks) and 4 post-fenfluramine. Plasma levels of fenfluramine and nor-fenfluramine indicated good compliance. Platelet serotonin concentration decreased in all 4 subjects, weight loss was noted in 2. Clinical changes (assessed by rating psychiatric symptoms and ward behaviour) were observed in 3: moderate sustained improvement in 1, a short-lived activation followed by a slight improvement in another, and a brief amelioration with subsequent worsening in the third. The time and pattern of these changes suggest that they were due to fenfluramine.

Responses of prolactin and growth hormone to L-tryptophan infusion: effects in normal subjects and schizophrenic patients receiving neuroleptics.

Intravenous infusion of L-tryptophan (LTP) in 18 normal subjects produced a significant increase in plasma prolactin (PRL), growth hormone (GH), and self-ratings of drowsiness. There was no correlation between the PRL and GH responses, or between the hormonal responses and drowsiness. Saline infusion did not result in endocrine or psychological changes. The effect of LTP on both PRL and GH was dose-related in that LTP 7.5 g produced greater endocrine responses than 5.0 g. It was not significantly decreased by cyproheptadine, a 5-HT receptor antagonist. Schizophrenic patients receiving neuroleptics had increased PRL response to LTP, possibly because of the drug-induced disinhibition of PRL release. Their GH response to LTP was markedly decreased. The mechanism of this effect requires further investigation.