What is it?

Tenofovir is an antiviral medication that is able to inhibit enzymes necessary for HIV and Hepatitis B Virus (HBV) to reproduce. Viruses like HIV and HBV use the genetic material in the body’s cells to produce more virus which can infect other cells. Tenofovir is currently approved by the Food and Drug Administration (FDA) for the treatment of HIV. Because tenofovir may also decrease the amount of HBV found in the bloodstream, it is currently being studied as a treatment to prevent liver damagethat is caused by HBV.

How does it work?

Tenofovir interferes with the life cycles of HIV and HBV to stop them from producing more virus. Specifically, tenofovir ties up the DNA polymerase enzyme so that HIV and HBV cannot build the genetic material needed to make more virus and infect more cells.

For the treatment of HIV, a specific DNA polymerase enzyme called reverse transcriptase is blocked. Because of this, tenofovir is commonly called a nucleotide reverse transcriptase inhibitor (NtRTI). When treating HIV, this medication is used in combination with other antiretroviral drugs to inhibit HIV reproduction.

How do I take it?

· Tenofovir is available as a 300 mg tablet.

· The usual dose is 1 tablet (300mg) once a day at the same time every day.

· Tenofovir should be taken with food to minimize the variation in the amount of medication that is absorbed into the blood stream.

It is extremely important that you take tenofovir and any other antiviral medications exactly as directed. You should set up a system that will help you remember to take your medicines so that you do not miss any doses. If you miss a dose, take it as soon as possible; however, if you skip a dose, do not take two doses at once. Do not stop taking the medication for any reason at any time unless you are directed to do so by your study clinician. If you are unable to continue taking your medication due to side effects, you should contact your study clinician immediately.

Special Considerations

· Tenofovir should be stored at controlled room temperature in a dry place, out of the reach of children.

· Please bring your medication bottles (empty and partially used) to each study visit.

Interactions

Some drugs taken together may have interactions that cause illness or impair the effectiveness of the drugs. It is a good idea to always check with your provider before taking any other medications, prescription or otherwise, to be sure it will not interact with tenofovir.

Side Effects

Not everyone experiences side effects. When they do occur, they may be mild, moderate or severe. Some side effects cannot be felt by the patient but can be found through laboratory tests, so it is important to see your provider regularly for checkups so that side effects can be detected early and treated.

Possible side effects of tenofovir include upset stomach, nausea, vomiting, and diarrhea.

Last Updated: 6/6/02