Drug Combinations With Efavirenz, Emtricitabine, and Tenofovir to Avoid
Efavirenz, emtricitabine, and tenofovir may increase the level of certain hormonal contraceptives in your blood. Since it is not known exactly how this will affect the effectiveness of the hormonal contraceptive, it is recommended that a non-hormonal method of birth control (such as condoms) be used.
In general, efavirenz, emtricitabine, and tenofovir should not be taken with medications that contain lamivudine, since emtricitabine (one of the components of the combination drug) and lamivudine are similar medications.
Efavirenz may decrease the level of Maraviroc in your blood, perhaps making it less effective. If you take these medications together, you may need a higher Maraviroc dosage.
Efavirenz, emtricitabine, and tenofovir can decrease the level of methadone in your blood, perhaps making it less effective. Your healthcare provider may need to increase your methadone dosage to prevent this interaction from occurring.
NSAIDs may interfere with the kidneys' ability to remove tenofovir from the blood. In addition, combining efavirenz, emtricitabine, and tenofovir with high doses of an NSAID or with multiple NSAIDs may increase the risk of kidney failure. It's best to check with your healthcare provider before combining efavirenz, emtricitabine, and tenofovir with any NSAID, including nonprescription ones.
Pimozide and efavirenz, emtricitabine, and tenofovir should not be taken together, due to the risk of serious or life-threatening reactions, such as an irregular heart rhythm (arrhythmia).
Combining efavirenz, emtricitabine, and tenofovir with a protease inhibitor can either increase or decrease the level of the HIV medication and the protease inhibitor in your blood. Your healthcare provider may need to adjust the dose of efavirenz, emtricitabine, and tenofovir and your protease inhibitor to prevent interactions from occurring.