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: caffeine, fezolinetant, theophylline, drugs that may affect the acid level of urine (such as sodium bicarbonate, large doses of vitamin C).

Other medications can affect the removal of mexiletine from your body, which may affect how mexiletine works. Examples include cimetidine, fluvoxamine, propafenone, anti-seizure drugs (such as phenytoin, phenobarbital), among others.