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: orlistat, other drugs that may affect the kidneys (including adefovir, cidofovir, aminoglycosides such as amikacin/ gentamicin), a certain combination product used to treat chronic hepatitis C (ombitasvir/paritaprevir/ritonavir/dasabuvir).

Do not take this medication with other products that contain emtricitabine or tenofovir. Do not take this medication with another efavirenz product unless specifically directed by your doctor. Also, lamivudine is similar to emtricitabine and should not be taken with this medication.

Other medications can affect the removal of efavirenz/emtricitabine/tenofovir from your body, which may affect how this product works. Examples include some drugs used to treat seizures (such as carbamazepine), among others.

Efavirenz/emtricitabine/tenofovir can speed up the removal of many other medications from your body, which may affect how they work. Examples of affected drugs include atazanavir, atovaquone/proguanil, azole antifungals (such as voriconazole), bedaquiline, cobicistat, elbasvir/grazoprevir, elvitegravir, macrolide antibiotics (such as clarithromycin), sofosbuvir/velpatasvir, 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 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 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 diazepam, zolpidem), muscle relaxants, and opioid pain relievers (such as codeine).

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 urine cannabinoid tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.