tenofovir

Generic Name: tenofovir (ten OF oh vir)
Brand Name: Viread

What is tenofovir?

Tenofovir is an antiviral medication that prevents human immunodeficiency virus (HIV) or hepatitis B virus cells from multiplying in your body.

Tenofovir is used to treat HIV, which causes the acquired immunodeficiency syndrome (AIDS). Tenofovir is not a cure for HIV or AIDS. Tenofovir is also used to treat chronic hepatitis B.

Tenofovir may also be used for purposes not listed in this medication guide.

What is the most important information I should know about tenofovir?

Do not take tenofovir together with adefovir (Hepsera), or with combination medicines that contain tenofovir (Atripla, Complera, or Truvada).

Tenofovir should not be given to a child with HIV who is younger than 2 years old. Tenofovir should not be used to treat hepatitis B in anyone younger than 18 years old.

Some people develop lactic acidosis while taking tenofovir. Early symptoms may get worse over time and this condition can be fatal. Get emergency medical help if you have even mild symptoms such as: muscle pain or weakness, numb or cold feeling in your arms and legs, trouble breathing, stomach pain, nausea with vomiting, fast or uneven heart rate, dizziness, or feeling very weak or tired.

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Tenofovir can also cause severe or life-threatening effects on your liver. Call your doctor at once if you have any of these symptoms while taking tenofovir: nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

If you have hepatitis B you may develop liver symptoms after you stop taking this medication, even months after stopping. Your doctor may want to check your liver function for several months after you stop using tenofovir. Visit your doctor regularly.

HIV/AIDS is usually treated with a combination of drugs. Use all medications as directed by your doctor. Do not change your doses or medication schedule without your doctor's advice. Every person with HIV or AIDS should remain under the care of a doctor.

What should I discuss with my healthcare provider before taking tenofovir?

Do not use this medication if you have ever had an allergic reaction to a medicine containing tenofovir, including Atripla, Complera, or Truvada.

Do not take tenofovir together with adefovir (Hepsera), or with combination medicines that contain tenofovir (Atripla, Complera, or Truvada).

Tenofovir should not be given to a child with HIV who is younger than 2 years old. Tenofovir should not be used to treat hepatitis B in anyone younger than 18 years old.

To make sure you can safely take tenofovir, tell your doctor if you have any of these other conditions:

• liver disease (especially hepatitis B if you also have HIV);

• kidney disease; or

• bone problems (such as osteopenia).

Some people develop a life-threatening condition called lactic acidosis while taking tenofovir. You may be more likely to develop lactic acidosis if you are overweight or have liver disease, if you are a woman, or if you have taken HIV or AIDS medications for a long time. Talk with your doctor about your individual risk.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby, but HIV can be passed to your baby if you are not properly treated during pregnancy. Take all of your HIV medicines as directed to control your infection.

If you are pregnant, your name may be listed on a pregnancy registry. This is to track the outcome of the pregnancy and to evaluate any effects of tenofovir on the baby.

Tenofovir can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are using tenofovir to treat hepatitis B. Women with HIV or AIDS should not breast feed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.

How should I take tenofovir?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Before you start treatment with tenofovir, your doctor may perform tests to make sure you do not have HIV (if you are being treated for hepatitis B) or hepatitis B (if you are being treated for HIV).

Tenofovir tablets may be taken with or without food.

Tenofovir oral powder should be taken with food. Mix the powder with soft food such as applesauce, yogurt, or baby food. Do not mix tenofovir oral powder with liquid.

This medication comes with patient instructions for safe and effective use. Follow these directions carefully. Ask your doctor or pharmacist if you have any questions.

Use tenofovir regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

HIV/AIDS is usually treated with a combination of drugs. Use all medications as directed by your doctor. Read the medication guide or patient instructions provided with each medication. Do not change your doses or medication schedule without your doctor's advice. Every person with HIV or AIDS should remain under the care of a doctor.

To be sure this medicine is helping your condition and is not causing harmful effects, your blood will need to be tested often. Your liver and kidney function may also need to be tested. Visit your doctor regularly.

If you have hepatitis B you may develop liver symptoms after you stop taking this medication, even months after stopping. Your doctor may want to check your liver function for several months after you stop using tenofovir. Visit your doctor regularly.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking tenofovir?

Avoid drinking alcohol. It may increase your risk of liver damage.

Taking this medication will not prevent you from passing HIV to other people. Avoid having unprotected sex or sharing razors or toothbrushes. Talk with your doctor about safe ways to prevent HIV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.

Tenofovir side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

This medication may cause lactic acidosis (a build-up of lactic acid in the body, which can be fatal). Lactic acidosis can start slowly and get worse over time. Get emergency medical help if you have even mild symptoms of lactic acidosis, such as: muscle pain or weakness, numb or cold feeling in your arms and legs, trouble breathing, stomach pain, nausea with vomiting, fast or uneven heart rate, dizziness, or feeling very weak or tired.

Call your doctor at once if you have a serious side effect such as:

• liver damage - nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

• kidney problems - increased thirst and urination, loss of appetite, constipation, urinating less than usual or not at all;

• signs of a new infection such as fever, chills, sore throat, flu symptoms, easy bruising or unusual bleeding, loss of appetite, mouth sores;

• increased sweating, tremors in your hands, anxiety, feeling irritable, sleep problems (insomnia);

• diarrhea, unexplained weight loss, menstrual changes, impotence, loss of interest in sex;

• swelling in your neck or throat (enlarged thyroid);

• problems with walking, breathing, speech, swallowing, or eye movement; or

• severe lower back pain, loss of bladder or bowel control.

Less serious side effects may include:

• mild nausea or diarrhea;

• depression, headache, dizziness, mild weakness;

• mild itching or rash; or

• changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and waist).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: tenofovir side effects (in more detail)

Tenofovir Dosing Information

Usual Adult Dose for HIV Infection:

300 mg orally once a day

Usual Adult Dose for Chronic Hepatitis B:

300 mg orally once a day
The optimum duration of treatment is not known.

Usual Adult Dose for Nonoccupational Exposure:

(Not approved by FDA)

Centers for Disease Control and Prevention (CDC) recommendations: 300 mg orally once a day plus efavirenz plus (emtricitabine or lamivudine)

Duration: 28 days

Prophylaxis should be initiated as soon as possible, within 72 hours of exposure.

Usual Pediatric Dose for HIV Infection:

2 to less than 12 years: 8 mg/kg orally once a day
Maximum: 300 mg/dose

Dosage based on body weight for pediatric patients 2 years or older:
Using oral powder:
10 to less than 12 kg: 80 mg (2 scoops of powder) orally once a day
12 to less than 14 kg: 100 mg (2.5 scoops of powder) orally once a day
14 to less than 17 kg: 120 mg (3 scoops of powder) orally once a day
17 to less than 19 kg: 140 mg (3.5 scoops of powder) orally once a day
19 to less than 22 kg: 160 mg (4 scoops of powder) orally once a day
22 to less than 24 kg: 180 mg (4.5 scoops of powder) orally once a day
24 to less than 27 kg: 200 mg (5 scoops of powder) orally once a day
27 to less than 29 kg: 220 mg (5.5 scoops of powder) orally once a day
29 to less than 32 kg: 240 mg (6 scoops of powder) orally once a day
32 to less than 34 kg: 260 mg (6.5 scoops of powder) orally once a day
34 to less than 35 kg: 280 mg (7 scoops of powder) orally once a day
35 kg or greater: 300 mg (7.5 scoops of powder) orally once a day

Using tablets:
17 to less than 22 kg: 150 mg orally once a day
22 to less than 28 kg: 200 mg orally once a day
28 to less than 35 kg: 250 mg orally once a day
35 kg or greater: 300 mg orally once a day

Weight should be monitored periodically and the tenofovir dose should be adjusted accordingly.

12 years or older (35 kg or more): 300 mg orally once a day

Usual Pediatric Dose for Chronic Hepatitis B:

12 years or older (35 kg or more): 300 mg orally once a day
The optimum duration of treatment is not known.

What other drugs will affect tenofovir?

Tell your doctor about all other medicines you use, especially:

• other HIV or AIDS medications such as atazanavir (Reyataz), didanosine (Videx), lopinavir and ritonavir (Kaletra);

• lithium (Eskalith, Lithobid);

• methotrexate (Rheumatrex, Trexall);

• pain or arthritis medicines such as aspirin (Anacin, Excedrin), acetaminophen (Tylenol), ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn, Naprelan, Treximet), celecoxib (Celebrex), diclofenac (Arthrotec, Cambia, Cataflam, Voltaren, Flector Patch, Pennsaid, Solareze), indomethacin (Indocin), meloxicam (Mobic), and others;

• medicines used to treat ulcerative colitis, such as mesalamine (Pentasa) or sulfasalazine (Azulfidine);

• medicines used to prevent organ transplant rejection, such as cyclosporine (Gengraf, Neoral, Sandimmune), sirolimus (Rapamune) or tacrolimus (Prograf);

• IV antibiotics such as amphotericin B (AmBisome, Amphotec, Abelcet), amikacin (Amikin), bacitracin (Baci IM), capreomycin (Capastat), gentamicin (Garamycin), kanamycin (Kantrex), streptomycin, or vancomycin (Vancocin, Vancoled);

• antiviral medicines such as acyclovir (Zovirax), adefovir (Hepsera), cidofovir (Vistide), foscarnet (Foscavir), ganciclovir (Cytovene), valacyclovir (Valtrex), or valganciclovir (Valcyte); or

• injectable medications to treat osteoporosis or Paget's disease of the bones, such as etidronate (Didronel), ibandronate (Boniva), pamidronate (Aredia), or zoledronic acid (Zometa, Reclast).

This list is not complete and other drugs may interact with tenofovir. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you.

Where can I get more information?

• Your pharmacist can provide more information about tenofovir.