What are the major side effects of irinotecan?

Irinotecan is a chemotherapy drug commonly used to treat colorectal cancer, and its major side effects primarily include diarrhea and abdominal cramping. This is particularly significant because irinotecan affects the gastrointestinal (GI) tract. The drug works by inhibiting topoisomerase I, an enzyme involved in DNA replication, but this mechanism can also lead to significant effects on the rapidly dividing cells of the GI lining.

The occurrence of diarrhea can vary from mild to severe, sometimes leading to dehydration, electrolyte imbalances, and necessitating supportive care or treatment with medications like loperamide to manage symptoms. Abdominal cramping often accompanies diarrhea as a result of the drug's impact on the intestinal motility.

Other choices presented pertain to side effects that are less commonly associated with irinotecan. Stomatitis and mucositis relate more frequently to other chemotherapeutic agents that have a notable effect on the oral and gastrointestinal mucosa but may not be as pronounced with irinotecan. Anaphylaxis and dyspnea are serious allergic reactions that can occur with many medications, including chemotherapy, but they are not typical side effects of irinotecan. Neurotoxicity and confusion are associated with other agents, particularly those that cross the blood-brain