Augmentation of prolactin response to TRH after cyproheptadine

Serum PRL, TSH, T3 and T4 were estimated in the basal state and following iv bolus injection of 100 micrograms synthetic thyrotropin releasing hormone before and 7 days after cyproheptadine treatment in 5 healthy adult males. Only the PRL response to TRH was augmented after cyproheptadine. This is perhaps related to the antidopaminergic effect of cyproheptadine.