What is Viread?
Viread (tenofovir disoproxil fumarate) is an antiviral medicine that prevents human immunodeficiency virus (HIV) from multiplying in your body.
Viread is used to treat HIV, the virus that can cause acquired immunodeficiency syndrome (AIDS).
Viread is not a cure for HIV or AIDS.
Health Benefits of Viread
Viread can help to:
– Reduce the amount of HIV in your body
– Boost your immune system
– Reduce your risk of infecting other people with HIV
– Improve your quality of life.
Side Effects
Viread can cause serious side effects, including:
– Kidney problems or kidney failure. Your risk may be higher if you have had kidney problems in the past, are 65 years of age or older, are taking other medications that can harm the kidneys, or take Viread with adefovir (Hepsera) or another medication that contains tenofovir. Tell your doctor right away if you have any kidney problems, including a decrease in the amount of urine, blood in your urine, change in the color of your urine, or pain while you urinate.
– Low levels of phosphate in your blood. Phosphate is needed for healthy bones and teeth. Tell your doctor if you have symptoms such as weakness, bone pain, or muscle aches.
– Lactic acidosis (too much lactic acid in the blood). Lactic acidosis is a serious but rare medical condition that can lead to death. Tell your doctor right away if you get signs of lactic acidosis: feeling weak or tired; unusual muscle pain; trouble breathing; stomach pain with nausea and vomiting; cold or blue hands and feet; feeling dizzy or light-headed; fast or irregular heartbeat.
– Hepatitis B virus (HBV) infection. If you have HIV and also have HBV, your HBV may suddenly get worse if you stop taking Viread. Do not stop taking Viread without first talking to your doctor, even if you feel fine. You may need ongoing medical care and regular blood tests for several months to check your HBV status.
Viread can also cause less serious side effects, such as:
– Headache
– Nausea
– Vomiting
– Diarrhea
– Stomach pain or upset
– Skin rash
These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Dosage of Viread
The recommended dose of Viread for adults and children weighing at least 35 kg is 300 mg once a day. For children weighing less than 35 kg, the recommended dose is based on body weight.
Viread can be taken with or without food.
If you miss a dose of Viread, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Interactions with Viread
Viread may interact with other medications. Tell your doctor all prescription and over-the-counter medications and supplements you use. During pregnancy, Viread should be used only when prescribed. This medication passes into breast milk. Consult your doctor before breastfeeding.
Mechanism of Action of Viread
Viread works by blocking an enzyme called reverse transcriptase. Reverse transcriptase is needed for the HIV virus to multiply. By blocking this enzyme, Viread reduces the amount of HIV in your body and helps boost your immune system. This makes it harder for you to get sick from HIV and lowers your risk of infecting other people with HIV.
Pharmacokinetics of Viread
Viread is rapidly absorbed after oral administration and reaches peak plasma concentrations in 2 to 4 hours. The bioavailability of Viread is approximately 60%. Viread is minimally bound to plasma proteins (<0.4%). Viread is eliminated primarily by the kidney via glomerular filtration with subsequent tubular secretion. The median apparent terminal elimination half-life of Viread following multiple once-daily dosing in subjects with normal renal function is approximately 17 hours. In subjects with impaired renal function, the elimination half-life of Viread increases and the systemic exposure (AUC) increases in a dose-dependent manner.
Alternatives to Viread
There are many other antiretroviral drugs available to treat HIV. Some common alternatives to Viread include:
– Atripla (efavirenz/emtricitabine/tenofovir)
– Combivir (lamivudine/zidovudine)
– Epzicom (abacavir/lamivudine)
– Truvada (emtricitabine/tenofovir)
– Ziagen (abacavir) Your doctor will determine the best treatment for you based on your individual medical situation.
