Plasma levels of benperidol, prolactin, and homovanillic acid after intravenous versus two different kinds of oral application of the neuroleptic in schizophrenic patients

Plasma levels of prolactin (PRL) and the butyrophenone neuroleptic benperidol (BPD) were closely followed 0 to 48 h after acute application of 6 mg BPD as intravenous injection, orally as liquid, and orally as tablets in 12 schizophrenic patients using a partially randomized cross over design. Drug concentrations showed application specific pharmacokinetic behavior with complete elimination within 48 h. All three applications led to a biphasic PRL response with pronounced initial plasma PRL peaks returning to baseline levels within 48 h. The results suggest that after acute neuroleptic challenge BPD plasma levels as low as 2-3 ng/ml can be sufficient for complete depletion of pituitary PRL …