Randomized phase III trial to compare the effectiveness of combination chemotherapy with or without PSC 833 followed by interleukin-2 or no further therapy in treating older patients who have acute myeloid leukemia. Some cancers become resistant to chemotherapy drugs. Combining PSC 833 with more than one chemotherapy drug may reduce resistance to the drugs and allow the cancer cells to be killed. Combining interleukin-2 with combination chemotherapy plus PSC 833 may kill more cancer cells.