Common toxicities of mammalian target of rapamycin inhibitors

The toxicities of newer targeted therapies are different from those seen with the traditional chemotherapy. Mammalian target of rapamycin (mTOR) inhibitors are evolving into an important class of drugs in oncology, and this class of drugs presents with a variety of different toxicities. Although similar to the toxicities seen in transplantation, these rapamycin analogs have unique side effects when compared to traditional chemotherapy agents. While most of the toxicities are mild, few can be severe and require routine monitoring. Mucositis and rash are the most common side effects. The metabolic toxicities, hyperglycemia, hyperlipidemia, and hypophosphatemia are different from the side effects traditionally seen with chemotherapy. This review will focus on the common toxicities seen with the mTOR inhibitors.