Cyproheptadine hydrochloride shares the actions and uses of the other antihistamines. In addition, cyproheptadine is used for the treatment of cold urticaria, and some clinicians consider it the drug of choice for the treatment of this condition.
Cyproheptadine has been effective in some patients for the treatment of Cushing's syndrome secondary to pituitary disorders. Clinical remissions and normalization of cortisol indexes (i.e., cortisol secretion rate, plasma cortisol concentration, urinary free cortisol excretion) reportedly occur in up to 60% of patients, generally within 1-3 months after beginning treatment. Although almost all of these patients relapse after discontinuance of cyproheptadine, prolonged remission (e.g., for at least 2.5-3 years) has occurred in a few patients following discontinuance of the drug. If relapse occurs, additional courses of therapy usually produce further responses. The role of cyproheptadine in the treatment of Cushing's syndrome secondary to pituitary disorders remains to be clearly established; in most patients, other therapy (e.g., surgery, radiation therapy) is preferred.
Cyproheptadine has been effective for the management of inhibited male or female orgasm (anorgasmy) induced by tricyclic antidepressants, monoamine oxidase inhibitors, fluoxetine, or antipsychotic agents. Ability to achieve orgasm was restored when cyproheptadine was administered 1-2 hours before anticipated sexual activity (e.g., 4-12 mg) or daily (e.g., 1-16 mg daily). Although not clearly established, the efficacy of cyproheptadine in these patients may be related to its serotonin antagonist or anticholinergic activity. However, the potential for drug interaction (possibly resulting in anticholinergic toxicity or additive CNS depression) in patients receiving any of these drugs concomitantly with cyproheptadine should be kept in mind. In a limited number of patients receiving cyproheptadine for fluoxetine-induced ejaculatory dysfunction, cyproheptadine reversed the antidepressant effects of fluoxetine. The mechanism of this drug interaction is not known, but it has been postulated that cyproheptadine, a serotonin antagonist, may inhibit the serotonergic effects of fluoxetine.
Although there are few indications for clinical use, cyproheptadine has been shown to stimulate appetite and weight gain in children and adults. There is evidence that cyproheptadine may be of some value in the management of anorexia nervosa, but the drug may be more effective in patients with anorexia nervosa who do not undertake periodic episodes of binge eating (nonbulimic) than those who do (bulimic).
Cyproheptadine reportedly has been effective in some patients for the management of vascular headaches (e.g., migraine). While clinical efficacy of cyproheptadine in the prophylaxis of migraine headache has not been established in randomized controlled studies, some experts consider the drug to be effective based on consensus and clinical experience. For further information on management and classification of migraine headache,
Cyproheptadine reportedly has been effective in some patients for the management of Nelson's syndrome, virilizing congenital adrenal hyperplasia in adult females, galactorrhea-amenorrhea syndrome, and carcinoid syndrome.
Cyproheptadine has been used as an adjunct to somatropin (human growth hormone) therapy in a limited number of children with somatotropin (endogenous growth hormone) deficiency. Combined therapy with the drugs was more effective in promoting weight gain and linear growth in these children than somatropin alone, but additional study is necessary.