• What Is Atripla?
• Who Should Take Atripla?
• What About Drug Resistance?
• How Is Atripla Taken?
• What Are the Side Effects?
• How Does Atripla React With Other Drugs?

What Is Atripla?

Atripla is a tablet that contains three antiretroviral drugs (ARVs) used to fight HIV: efavirenz (Sustiva), emtricitabine (Emtriva), and tenofovir (Viread). Atripla is manufactured by Gilead and Bristol-Myers Squibb. It is the first tablet that includes a complete antiretroviral regimen. A generic version was approved for sale outside the U.S. under the PEPFAR program (see Fact Sheet 475).

The drugs in Atripla are a non-nucleoside reverse transcriptase inhibitor (efavirenz) and two nucleoside analog reverse transcriptase inhibitors, or nukes (emtricitabine and tenofovir). These drugs block the reverse transcriptase enzyme. This enzyme changes HIV's genetic material (RNA) into the form of DNA. This has to occur before HIV's genetic code gets inserted into an infected cell's own genetic codes.

Who Should Take Atripla?

Atripla was approved in 2006 as an ARV for adults with HIV infection. Atripla should not be used in people younger than age 18. It has not been carefully studied in older adults. People with liver or kidney problems may not be able to take Atripla.

There are no absolute rules about when to start antiretroviral therapy (ART). You and your health care provider should consider your CD4 cell count, your viral load, any symptoms you are having, and your attitude about taking ART. Fact Sheet 404 has more information about guidelines for the use of ART.

If you take Atripla, you can reduce your viral load to extremely low levels, and increase your CD4 cell counts. This should mean staying healthier longer.

Atripla provides three drugs in one pill. It can be more convenient to use Atripla than some other combinations of drugs. This could mean fewer missed doses and better control of HIV. Atripla can be an effective regimen of ARVs in one pill.

What About Drug Resistance?

Many new copies of HIV are mutations. They are slightly different from the original virus. Some mutations can keep multiplying even when you are taking an ARV. When this happens, the drug will stop working. This is called "developing resistance" to the drug. See Fact Sheet 126 for more information on resistance.

Sometimes, if your virus develops resistance to one drug, it will also have resistance to other ARVs. This is called "cross-resistance".

Resistance can develop quickly. It is very important to take ARVs according to instructions, on schedule, and not to skip or reduce doses.

How Is Atripla Taken?

Atripla is taken by mouth as a tablet. The normal adult dose is one tablet, once a day. Each tablet includes 600 milligrams (mg) of efavirenz, 200 mg of emtricitabine, and 300 mg of tenofovir.

Atripla should be taken on an empty stomach. Taking Atripla at bedtime may help reduce side effects. If you miss your dose, you can take Atripla up to 12 hours late. Otherwise, take your next dose at the regular time.

Food with high fat content can increase levels of efavirenz and should not be eaten before taking a dose of Atripla.

What Are the Side Effects?

When you start any ART, you may have temporary side effects such as headaches, high blood pressure, or a general sense of feeling ill. These side effects usually get better or disappear over time.

The most common side effects of Atripla are the same as with the drugs it contains: efavirenz, emtricitabine, and tenofovir. They include headache, diarrhea, nausea, vomiting, vivid dreams, anxiety, rash, dizziness, insomnia, and loss of appetite.

About 5% of patients taking efavirenz had serious psychiatric symptoms. If you are taking Atripla and experience serious depression or other psychiatric symptoms, talk to your health care provider right away.

If you have had hepatitis B or C, your liver function tests may increase significantly. These should be monitored carefully.

Studies in monkeys showed that efavirenz is likely to cause birth defects. Pregnant women should not take Atripla, especially during the first 3 months of pregnancy.

People who take Atripla may falsely test positive for marijuana use. To prove that the results are false, you would have to identify the drug that you are taking. This would mean disclosing that you have HIV infection.

How Does Atripla React With Other Drugs?

Atripla can interact with other drugs or supplements you are taking. These interactions can change the amount of each drug in your bloodstream and cause an under- or overdose. New interactions are constantly being identified. Make sure that your health care provider knows about ALL drugs and supplements you are taking.

Drugs to watch out for include other ARVs, drugs to treat tuberculosis (see Fact Sheet 518), for erectile dysfunction (such as Viagra), for heart rhythm (antiarrhythmics), and for migraine headaches. Interactions are also possible with several antihistamines (allergy medications), sedatives, drugs to lower cholesterol, and anti-fungal drugs.

Efavirenz decreases blood levels of methadone. Efavirenz can lower concentrations of buprenorphine. Be aware of these interactions if you take Atripla.

The herb St. John's Wort (See Fact Sheet 729) lowers the blood levels of some non-nucleoside reverse transcriptase inhibitors. Do not take it with Atripla.