Enhancement of linear growth and weight gain by cyproheptadine in children with hypopituitarism receiving growth hormone therapy.

Cyproheptadine (Cp), an antihistamine serotonin antagonist drug with appetite-stimulating activity, was given to children with growth hormone (GH) deficiency to test the hypothesis that increased weight gain would enhance the effect of GH on linear growth. Six patients with idiopathic GH deficiency received GH 0.08 U/kg three times per week plus Cp 0.25 to 0.4 mg/kg/day for 4-month periods, alternating with 4-month periods of GH plus placebo, on average for 16 months. Overall, height velocity (HV) increased from 9.1 +/- 2.4 with GH alone to 12.1 +/- 2.1 cm/yr with GH-Cp (P = 0.01) and weight velocity (WV) increased substantially from 1.3 +/- 1.3 to 7.8 +/- 3.6 kg/yr (P = 0.01). For 10 of 11 8-month treatment intervals completed, HV was greater during GH-Cp treatment than during GH alone, and there was a good correlation between HV and WV for each 4-month observation period (r = 0.64, P less than 0.002). These findings should be considered preliminary because of the small number of patients, but suggest that weight gain induced by cyproheptadine results in improved linear growth in patients given GH and that this drug may be useful in optimizing the response to GH therapy.