See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug are: drugs that reduce stomach acid (such as antacids, H2 blockers such as famotidine/ranitidine, proton pump inhibitors such as omeprazole/lansoprazole).

Other medications can affect the removal of neratinib from your body, which may affect how neratinib works. Examples include azole antifungals (such as ketoconazole, itraconazole), macrolide antibiotics (such as clarithromycin), nefazodone, HIV protease inhibitors (such as indinavir, nelfinavir), rifamycins (such as rifabutin, rifampin), ritonavir, St. John's wort, drugs used to treat seizures (such as carbamazepine, phenytoin), telithromycin, among others.