Microtubule inhibitors, anthracyclines and topoisomerase inhibitors

At a glance

• Microtubule inhibitors (vinca alkaloids, taxanes, eribulin) disrupt the mitotic spindle and arrest cells in M phase. Microtubules also carry axonal transport, so peripheral neuropathy is the class toxicity.
• Topoisomerase poisons trap the enzyme on DNA after it has cut. Topoisomerase I inhibitors leave single-strand breaks; topoisomerase II inhibitors leave double-strand breaks.
• Anthracyclines intercalate into DNA, poison topoisomerase II and generate iron-dependent free radicals. Cumulative dose-dependent cardiomyopathy is the exam topic.