Dextromethorphan in Treating Patients With Fatigue Caused by Cancer

DISEASE CHARACTERISTICS: Diagnosis of malignancy Must be undergoing active treatment for malignancy which may include hormonal therapy (e.g., tamoxifen citrate or leuprolide acetate), but not radiotherapy alone Fatigue score ≥ 4 on a verbal analogue scale of 0 to 10 No untreated cancer-related anemia PATIENT CHARACTERISTICS: Hemoglobin > 10 g/dL Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Able to swallow pills No known allergy to dextromethorphan hydrobromide No patients known to be phenotypically poor metabolizers of CYP2D6 No untreated hypothyroidism PRIOR CONCURRENT THERAPY: See Disease Characteristics Prior single-dose inhibitors (e.g., ranitidine or cimetidine) for hypersensitivity prophylaxis allowed Erythropoietic growth factor therapy of > 8 weeks duration allowed No concurrent CYP2D6 inducers or inhibitors No concurrent monoamine oxidase inhibitors No other concurrent medications containing dextromethorphan hydrobromide No concurrent over-the-counter medication, herbal product, vitamin, food supplement, or any other type of special product unless permission to continue use is obtained from the Principal Investigator No other concurrent anticancer investigational agents or therapies