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.

Other medications can affect the removal of naldemedine from your body, which may affect how naldemedine works. Examples include enzalutamide, lumacaftor/ivacaftor, mitotane, rifamycins (such as rifampin), St. John's wort, drugs used to treat seizures (such as carbamazepine, phenobarbital, phenytoin, primidone), among others.