Administration of cis-dichlorodiammineplatinum(II) may be associated with a number of serious side effects, including nephrotoxicity, gastroeintestinal side effects (nausea, vomiting, and diarrhea), myelosuppression, and occasional transient elevations in liver function tests. In addition, ototoxicity (tinnitus and hearing loss), anaphylactic reactions, peripheral neuropathies, and hypomagnesemia with resulting tetany may also be encountered. The toxic potential of this new agent necessitates careful clinical monitoring during treatment.