Effect of cyproheptadine hydrochloride on ingestive behaviors.

Cyproheptadine (CY) has been used therapeutically as an appetite stimulant at a dose which appears to have antiserotoninergic activity. However, the role which CY may play in appetite regulation remains unclear. This study was designed to examine the effect of CY on ingestive behaviours in female Wistar rats. CY administered orally (0.52 mg kg-1 b.w., dissolved in the daily water) for up to six oestrus cycles did not affect 24 h food intake. On the other hand, CY reduced both 24 h liquid intake and 24 h urine output. Furthermore, 24 h liquid consumption and 24 h urine output, were found to fluctuate according to the oestrus cycle.