Viread – brand name

tenofovir DF – generic name

Viread belongs to a class of HIV drugs called nucleotide/nucleoside reverse transcriptase inhibitors (NRTIs or “nukes”). Viread is the only approved nucleotide reverse transcriptase inhibitor. There are many approved nucleoside reverse transcriptase inhibitors, such as Retrovir (zidovudine or AZT) and Epivir (lamivudine or 3TC). All NRTIs work in a similar way.

The NRTIs block reverse transcriptase, a protein that HIV needs to make more copies of itself. This may slow down HIV disease.

The Food and Drug Administration (FDA) has approved Viread for use in combination with other HIV drugs for the treatment of HIV infection in adults over 18 years old.

Viread comes in 300 milligram (mg) tablets.

The dose is one tablet, once a day.

If you have a kidney problem, your dose of Viread may need to be lowered.

Viread must be used with other HIV medications to treat HIV, usually with at least one other NRTI and either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI). It should not be used only with other NRTIs.

You can take Viread with food or on an empty stomach.

Combination tablets containing Viread and other HIV drugs are also available:

• Truvada: Viread and Emtriva (emtricitabine or FTC)
• Atripla: Viread, Emtriva, and Sustiva (efavirenz)

For more information on these combination pills, see our fact sheets on Truvada and Atripla.

Viread is one of the easiest HIV drugs to take—you take one pill, once a day. Once-daily drugs are convenient but you have to make sure you take Viread exactly as prescribed.

Missing or skipping doses can cause your blood levels of Viread to fall too low and resistance can develop. This may cause Viread and any other HIV drugs you may be taking to stop working.

If you miss your dose of Viread, take it as soon as possible, but do not double up on your next dose.

Viread can be used if you are beginning treatment for the first time.

Viread may be a good choice for people who have HIV that is resistant to other NRTIs, such as Retrovir (zidovudine or AZT), Epivir (lamivudine or 3TC), Zerit (stavudine or d4T), Videx EC (didanosine or ddI), and Ziagen (abacavir).

Viread may not be effective for people whose HIV is resistant to certain drugs.

You and your health care provider should use resistance testing and your treatment history to help guide the use of Viread and to determine which drugs will work best for you.

If your virus develops resistance to Viread then it may stop working or not work as well for you. You also may not get as much benefit from the other NRTIs.

Sometimes taking more than one medication can cause drug interactions. This can lead to the drugs not working as well or an increased risk of side effects.

Viread can interact with other medications. Taking Viread with certain drugs can change the amount of each drug in your blood. Your health care provider may need to either adjust the doses of your drugs to avoid under- or overdosing or to change the drugs you currently take.

Viread should not be combined with:

• Atripla (Sustiva + Emtrivia + Viread)
• Truvada (Emtriva + Viread)
• Hepsera (adefovir dipivoxil)

Viread can increase Videx EC levels in the blood – this might increase the risk of side effects caused by Videx EC, such as pancreatitis (damage to the pancreas) and peripheral neuropathy. If you are taking these drugs together, your doctor will likely lower your dose of Videx EC and monitor you for side effects. Because of concerns about the use of Viread with Videx EC, it may be best to avoid this combination altogether.

The protease inhibitors Reyataz (atazanavir) and Kaletra (lopinavir/ritonavir) can increase the amount of Viread in the blood, which could result in more side effects. You may need to be followed more carefully if you are taking Viread and Reyataz or Kaletra together. Viread also reduces Reyataz levels in the blood. If you are taking these drugs together, your health care provider should also prescribe a low dose (100 mg) of Norvir (ritonavir) to increase or “boost” the amount of Reyataz in the bloodstream.

The following combinations containing Viread should not be used:

• Viread plus Epivir plus Ziagen
• Viread plus Epivir plus Videx EC
• Viread plus Videx EC plus Sustiva in patients new to HIV therapy
• Viread plus Videx EC plus Viramune (nevirapine) in patients new to HIV therapy
• Viread plus Videx EC plus Rescriptor (delavirdine) in patients new to HIV therapy
  

Be sure your health care provider knows about all the medications you are taking (including over-the-counter, prescription, street drugs, and herbs), even if you only use them occasionally.

For more information and additional resources to check interactions between the particular drugs you are taking, see our info sheet on drug interactions or go to:

http://www.hiv-druginteractions.org/
OR
http://hivinsite.ucsf.edu/insite?page=ar-00-02

Viread is generally well tolerated. If you do experience any side effects from Viread, they are likely to be temporary and go away as your body adjusts to the medication. If you experience any of the side effects listed below, call your health care provider for advice. Do not just stop taking your medication.

• Rash
• Headache
• Pain
• Diarrhea
• Depression
• Weakness
• Nausea
• Vomiting
• Dizziness
• Intestinal gas (flatulence)

More serious side effects:

• Kidney problems: Have your creatinine levels (blood test for kidneys) monitored regularly. High levels can indicate kidney damage. It may also be helpful to have a urine test to check on your kidneys. High levels of protein can indicate kidney damage.
• Bone problems such as osteoporosis or osteopenia (brittle bones)
• An increase of lactic acid in the blood ( lactic acidosis), an enlarged and fatty liver, and liver failure have been reported in people using NRTIs. Lactic acidosis is a rare but potentially fatal side effect. Symptoms include nausea, vomiting, or stomach pain; feeling very weak and tired; shortness of breath.
• Lipodystrophy, which may include elevated blood sugar (glucose), elevated lipid levels ( cholesterol and triglycerides), and fat gain or loss in certain areas. The exact causes of lipodystrophy are not known, but may include HIV and/or HIV drugs. It is unclear if Viread will cause or impact symptoms of lipodystrophy. For more information on lipodystrophy, see our info sheet.

If you are experiencing persistent, unusual, or serious side effects, call your health care provider right away.

Study 903 looked at 600 people who had not taken HIV drugs before, including 26 percent women, or about 156 women. In this study, Viread plus Epivir plus Sustiva and Zerit plus Epivir plus Sustiva worked about equally well. But elevated blood fat levels and fat loss in the arms and legs (lipoatrophy) were less likely in people taking Viread.

Study 907 looked at 550 people who added either Viread or a placebo (sugar pill) to their existing HIV regimens. This study included 15 percent women, or about 82 women. After 24 weeks, 19 percent of those taking Viread achieved HIV viral loads below 50 copies, compared with just 1 percent of those taking the placebo.

In terms of side effects, research has shown that the pharmacokinetics of Viread (how the drug is processed by the body) are similar in women and men. But past studies of medical records indicate that women (especially overweight women) taking NRTI drugs are more likely than men to develop elevated lactic acid levels and enlarged fatty livers. In addition, Viread can reduce bone mineral density.

Viread can reduce bone mineral density. Since HIV+ women may already be at higher risk for bone problems, it is important to get enough calcium and vitamin D and to ask your health care provider about a bone mineral density test.

Studies have shown that pregnant women who use HIV drugs can greatly reduce the risk of passing HIV on to their babies. There have been no formal studies on the use of Viread during pregnancy.

An Antiretroviral Pregnancy Registry has been established to collect information on pregnant women who take HIV drugs, including Viread. If you are pregnant and taking Viread or other HIV drugs, your health care provider can register you by calling 1-800-258-4263 or going to www.apregistry.com.

It is not known whether Viread passes into breast milk. HIV+ women should not breast-feed because their babies could be infected with HIV through the breast milk.

Check with your health care provider about the best treatment options for you and your baby if you are thinking of getting pregnant.

Click this link for more information about pregnancy.

Viread is also approved to treat hepatitis B virus (HBV). Get tested for HBV before you start taking Viread to treat HIV. If you are co-infected with HIV and HBV, speak to your health care provider about treatment options. In addition, if you are taking Viread for HIV treatment, discontinuing the drug may result in worsening hepatitis symptoms.

People who are starting HIV treatment for the first time may develop Immune Reconstitution Syndrome or IRS (also called Immune Reconstitution Inflammatory Syndrome or IRIS). IRS can happen as a result of the immune system getting stronger and responding to an HIV-related infection such as Mycobacterium avium infection (MAC), cytomegalovirus (CMV), Pneumocystis jirovecii pneumonia (PCP), or tuberculosis (TB). People may have been treated for these infections in the past or not even know they have them. If you notice any unusual symptoms soon after starting HIV drugs for the first time, let your health care provider know right away so you can be evaluated and, if necessary, treated.