Two drugs that are currently approved to treat symptoms of depression may also be effective against small cell lung cancer (SCLC). Researchers used bioinformatics, which combines mathematics and computer science to analyze large amounts of biological data, to pinpoint drugs likely to act on pathways that are important in SCLC. They identified the antidepressant imipramine (Tofranil) and the sedative/anti-nausea medication promethazine (Phenergan). Both drugs killed SCLC cells both in cell culture and in mouse models of chemotherapy-resistant SCLC. SCLC tumors arise from cells that are part of the hormone and nervous system, which may explain the effectiveness of these drugs. A new clinical trial will explore the effectiveness of desipramine (Norpramin), a drug similar to Tofranil, in SCLC.