A randomized, double-blind, placebo-controlled trial of cyproheptadine for appetite stimulation in cystic fibrosis

Objective: To determine whether the administration of cyproheptadine was able to induce weight gain in patients with cystic fibrosis. Methods: We performed a double-blind, placebo-controlled trial in two centers in Brazil. Twenty-five patients with cystic fibrosis between 5 and 18 years completed the study. Patients were randomized into two groups, to receive either cyproheptadine 4 mg three times per day for 12 weeks or placebo. All data were collected at the beginning and at the end of the study period and included weight, height and spirometry. Results: Average weight gain was 0.67 kg in the placebo group and 1.61 kg in the cyproheptadine group (p = 0.036). Body mass index (BMI) decreased 0.07 kg/m(2) in the placebo group and increased 0.46 kg/m2 in the intervention group (p = 0,027). The change in BMI for age (z score) was -0.19 in the placebo group and +0.20 in the cyproheptadine group (p = 0.003). BMI z score decreased 0.19 in the placebo group and increased 0.2 in the cyproheptadine group (p = 0.003). Changes in pulmonary function were not statistically different. Conclusion: Use of cyproheptadine in cystic fibrosis patients was well tolerated, showing a significant weight gain and a significant increase in BMI after 12 weeks. A clinically relevant effect size for weight/age (z score) and body mass index for age (z score) was found. Such findings suggest that the prescription of cyproheptadine can be an alternative approach for patients who need nutritional support for a short period of time.