Cyproheptadine in Preventing Weight Loss in Children Receiving Chemotherapy for Cancer

RATIONALE: Cyproheptadine hydrochloride may prevent weight loss caused by cancer or cancer treatment. It is not yet known whether cyproheptadine is more effective than a placebo in preventing weight loss in young patients receiving chemotherapy for cancer. PURPOSE: This randomized phase III trial is studying cyproheptadine hydrochloride to see how well it works in preventing weight loss in young patients receiving chemotherapy for cancer.