Ondansetron and tropisetron are 5-HT3 receptor antagonists used to treat nausea and vomiting and are commonly prescribed to patients who have undergone surgery or who are receiving chemotherapy. They are both covered by a CPIC guideline which can be accessed on the CPIC website.
PharmGKB has released two new pathways for these drugs; Ondansetron Pathway, Pharmacokinetics/Pharmacodynamics and Tropisetron Pathway, Pharmacokinetics/Pharmacodynamics. These pathways show the metabolism of both drugs as well as their action at 5-HT3 receptors on vagal afferent neurons. Key genes involved in the metabolism process are highlighted in the clickable images and described in the accompanying descriptions. Note that although ondansetron and tropisetron have very similar pharmacokinetic pathways, there are important differences between the two. This is why separate pathways have been produced for each drug.
You can view the Ondansetron Pathway,Pharmacokinetics/Pharmacodynamics and the Tropisetron Pathway,Pharmacokinetics/Pharmacodynamics on the PharmGKB website. Annotated versions of the CPIC guideline for ondansetron and tropisetron are also available at the PharmGKB website.