PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 3 months Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL ALT/AST no greater than 2.5 times upper limit of normal (ULN) Renal: Creatinine no greater than 1.5 times ULN Cardiovascular: No history of clinically significant cardiac arrhythmia that could be exacerbated by QT interval prolongation No uncontrolled or significant cardiovascular disease No myocardial infarction within the past 6 months No significant congestive heart failure No second- or third- degree heart block No prolonged QTc interval (greater than 450 ms) on EKG Pulmonary: No uncontrolled or significant pulmonary disease Other: No serious uncontrollable medical disorder or active infection that would preclude study No dementia or altered mental status that would preclude study Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception