PROLACTIN RESPONSE TO DL-FENFLURAMINE IN PANIC DISORDER

The objective of this study was to test the hypothesis that serotonin receptors are hypersensitive in patients with panic disorder. Eleven p atients and 12 controls received a single PO dose of 60 mg of dl-fenfl uramine at 0900h on a single occasion. Blood samples were collected wi th an indwelling intravenous catheter at 30-min intervals from 0930h t o 1530h and prolactin determined by radioimmunoassay. In both groups, fenfluramine induced a rise in the plasma prolactin concentration from baseline. The patients showed a greater increase in prolactin respons e than the normal controls. This result is consistent with the hypothe sis of increased serotonin receptor function in patients with panic di sorder.