Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription medication you may use, especially: calcium channel blockers (e.g., verapamil, felodipine), cyclosporine, other seizure control medication (e.g., carbamazepine, phenytoin, phenobarbital, valproic acid), a certain combination HIV medication (elvitegravir/cobicistat/emtricitabine/tenofovir).
This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use additional reliable birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.
Tell your doctor if you take any drugs that make you drowsy, such as: medicine for sleep, sedatives, tranquilizers, anti-anxiety drugs (e.g., diazepam), narcotic pain relievers (e.g., hydrocodone, codeine), psychiatric medicines (e.g., phenothiazines such as chlorpromazine, or tricyclics such as amitriptyline), muscle relaxants, antihistamines that cause drowsiness (e.g., diphenhydramine).
Check the labels on all your medicines (e.g., cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about the safe use of those products.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.