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 include: certain azole antifungals (isavuconazonium, voriconazole), orlistat.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.

Other medications can affect the removal of carbamazepine from your body, which may affect how carbamazepine works. Examples include macrolide antibiotics (such as erythromycin), rifamycins (such as rifabutin), St. John's wort, among others.

Carbamazepine can speed up the removal of other drugs from your body, which may affect how they work. Examples of affected drugs include artemether/lumefantrine, certain drugs used to prevent blood clots (anticoagulants such as apixaban, rivaroxaban), certain calcium channel blockers (such as nifedipine, nimodipine), nefazodone, HIV NNRTIs (such as efavirenz, etravirine, rilpivirine), praziquantel, ranolazine, among others.

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 reliable backup birth control methods while taking 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 or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana (cannabis), antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), and opioid pain relievers (such as codeine, hydrocodone).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

This medication may interfere with certain lab tests (such as thyroid function, some pregnancy tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.