The present disclosure provides methods of identifying subjects having an increased likelihood of developing one or more adverse side effects resulting from administration of a microtubule-stabilizing agent. In particular examples, the method includes determining whether the subject has an ABCB1 predictive polymorphism for microtubule-stabilizing agent-induced toxicity, wherein the presence of such a polymorphism indicates that the subject has an increased risk of developing microtubule-stabilizing agent induced adverse effects. Examples of ABCB1 predictive polymorphisms include 2677G>T/A and 3435C>T. Also provided are methods of modifying microtubule-stabilizing agent therapy in a subject identified as having one or more ABCB1 predictive polymorphisms. Kits and isolated nucleic acid molecules that can be used in the disclosed methods are also provided.