Generic drug: lamivudine and tenofovir disoproxil fumarate

Brand name: Temixys

What is Temixys (lamivudine and tenofovir disoproxil fumarate), and how does it work?

Temixys (lamivudine and tenofovir disoproxil fumarate) is indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adult and pediatric patients weighing at least 35 kg.

What are the side effects of Temixys?

WARNING

POSTTREATMENT EXACERBATIONS OF HEPATITIS B

Severe acute exacerbations of hepatitis B have been reported in patients who are co-infected with hepatitis B virus (HBV) and human immunodeficiency virus (HIV-1) and have discontinued lamivudine or tenofovir disoproxil fumarate. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue Temixys and are co-infected with HIV-1 and HBV. If appropriate, initiation of anti-hepatitis B therapy may be warranted.

Temixys may cause serious side effects, including:

  • New or worse kidney problems, including kidney failure. Your healthcare provider may do blood and urine tests to check your kidneys before and during treatment with Temixys. Tell your healthcare provider if you get signs and symptoms of kidney problems, including bone pain that does not go away or worsening bone pain, pain in your arms, hands, legs or feet, broken (fractured) bones, muscle pain or weakness.
  • Changes in your immune system (Immune Reconstitution Syndrome) can happen when an HIV-1 infected person start taking HIV-1 medicines. Your immune system may get stronger and begin to fight infections that have been hidden in your body for a long time. Tell your healthcare provider right away if you start having new symptoms after starting your HIV-1 medicine.
  • Bone problems can happen in some children or adults who take Temixys. Bone problems include bone pain, softening or thinning of bones, which may lead to fractures. Your healthcare provider may need to do tests to check your bones or your child's bones. Tell your healthcare provider if you have any bone pain, pain in your hands or feet, or muscle pain or weakness during treatment with Temixys.
  • Too much lactic acid in your blood (lactic acidosis). Too much lactic acid is a serious but rare medical emergency that can lead to death. Tell your healthcare provider right away if you get these symptoms: weakness or being more tired than usual, unusual muscle pain, being short of breath or fast breathing, stomach pain with nausea and vomiting, cold or blue hands and feet, feel dizzy or lightheaded, or a fast or abnormal heartbeat.
  • Severe liver problems. In rare cases, severe liver problems can happen that can lead to death. Tell your healthcare provider right away if you get these symptoms: skin or the white part of your eyes turns yellow, dark “tea-colored” urine, light-colored stools, loss of appetite for several days or longer, nausea, or stomach-area pain.
  • Use with interferon and ribavirin-based regimens. Worsening of liver disease that has caused death has happened in people infected with HIV-1 and hepatitis C virus who were taking antiretroviral medicines for HIV-1 and were also being treated for hepatitis C with interferon alfa with or without ribavirin. If you are taking Temixys and interferon with or without ribavirin, tell your healthcare provider if you have any new symptoms.
  • Risk of inflammation of the pancreas (pancreatitis). Children may be at risk for developing pancreatitis during treatment with Temixys if they:
    • have taken nucleoside analogue medicines in the past
    • have a history of pancreatitis
    • have other risk factors for pancreatitis

Call your healthcare provider right away if your child develops signs and symptoms of pancreatitis includingsevere upper stomach-area pain, with or without nausea and vomiting. Your healthcare provider may tell you to stop giving Temixys to your child if their symptoms and blood test results show that your child may have pancreatitis. The most common side effects of Temixys include:

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of Temixys.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the dosage for Temixys?

Testing Prior To Initiation And During Treatment With Temixys

  • Prior to initiation treatment with Temixys, test patients for hepatitis B virus infection.
  • Prior to initiation and during use of Temixys, on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorus.

Recommended Dose For Adult And Pediatric Patients Weighing At Least 35 kg

  • Temixys is a two-drug fixed-dose combination product containing 300 mg of lamivudine (3TC) and 300 mg of tenofovir disoproxil fumarate (TDF). The recommended dosage of Temixys in HIV-1 infected adult and pediatric patients weighing at least 35 kg is one tablet taken orally once daily with or without food.

Not Recommended In Renal Impairment

  • Because Temixys is a fixed-dose combination formulation and cannot be dose adjusted, it is not recommended for patients with impaired renal function (creatinine clearance less than 50 mL/min) or patients with end-stage renal disease (ESRD) requiring hemodialysis.

SLIDESHOW

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What drugs interact with Temixys?

Drugs Affecting Renal Function

Tenofovir, a component of Temixys, is primarily eliminated by the kidneys. Coadministration of Temixys with drugs that are eliminated by active tubular secretion may increase serum concentrations of tenofovir and/or coadministered drug. Some examples include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs. Drugs that decrease renal function may increase concentrations of tenofovir.

Do not administer Temixys with Hepsera (adefovir dipivoxil).

Established And Significant Interactions

Table 3 provides a listing of established or clinically significant drug interactions. The drug interactions described are based on studies conducted with TDF.

Table 3: Established and Significanta Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Trials

Concomitant Drug Class: Drug Name Effect on Concentrationb Clinical Comment
NRTI: didanosine ↑ didanosine Patients receiving TDF, a component of Temixys, and didanosine should be monitored closely for didanosine-associated adverse reactions. Discontinue didanosine in patients who develop didanosine-associated adverse reactions. Higher didanosine concentrations could potentiate didanosine-associated adverse reactions, including pancreatitis, and neuropathy. Suppression of CD4+ cell counts has been observed in patients receiving TDF with didanosine 400 mg daily.
In patients weighing greater than 60 kg, reduce the didanosine dose to 250 mg when it is coadministered with TDF. In patients weighing less than 60 kg, reduce the didanosine dose to 200 mg when it is coadministered with TDF. When coadministered, tenofovir disoproxil fumarate and Videx - EC may be taken under fasted conditions or with a light meal (less than 400 kcal, 20% fat).
HIV-1 Protease Inhibitors: Atazanavir
lopinavir/ritonavir
atazanavir/ritonavir
darunavir/ritonavir
↓ atazanavir
↑ tenofovir
When coadministered with Temixys, atazanavir 300 mg should be given with ritonavir 100 mg.
Monitor patients receiving Temixys concomitantly with lopinavir/ritonavir, ritonavir-boosted atazanavir, or ritonavir-boosted darunavir for TDF-associated adverse reactions. Discontinue Temixys in patients who develop TDF-associated adverse reactions.
Hepatitis C Antiviral Agents: sofosbuvir/velpatasvir
sofosbuvir/velpatasvir/ voxilaprevir
ledipasvir/sofosbuvir
↑ tenofovir Monitor patients receiving Temixys concomitantly with Epclusa (sofosbuvir/velpatasvir) for adverse reactions associated with TDF.
Monitor patients receiving Temixys concomitantly with Harvoni (ledipasvir/sofosbuvir) without an HIV-1 protease inhibitor/ritonavir or an HIV-1 protease inhibitor/cobicistat combination for adverse reactions associated with TDF. In patients receiving Temixys concomitantly with Harvoni and an HIV-1 protease inhibitor/ritonavir or an HIV-1 protease inhibitor/cobicistat combination, consider an alternative HCV or antiretroviral therapy, as the safety of increased tenofovir concentrations in this setting has not been established. If coadministration is necessary, monitor for adverse reactions associated with TDF.
a. This table is not all inclusive.
b. ↑=Increase, ↓=Decrease

Drugs Inhibiting Organic Cation Transporters

  • 3TC, a component of Temixys, is predominantly eliminated in the urine by active organic cationic secretion.
  • The possibility of interactions with other drugs administered concurrently should be considered, particularly when their main route of elimination is active renal secretion via the organic cationic transport system (e.g., trimethoprim).
  • No data are available regarding interactions with other drugs that have renal clearance mechanisms similar to that of 3TC.

Sorbitol

  • Coadministration of single doses of lamivudine and sorbitol resulted in a sorbitol dose-dependent reduction in lamivudine exposures. When possible, avoid use of sorbitol-containing medicines with lamivudine.

Is Temixys safe to use while pregnant or breastfeeding?

  • Available data from the APR show no difference in the risk of overall major birth defects for 3TC compared to the background rate for major birth defects of 2.7% in U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP).
  • Available data from the APR show no increase in the overall risk of major birth defects with first trimester exposure for tenofovir disoproxil fumarate (TDF) (2.1%) compared with the background rate for major birth defects of 2.7% in a U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP).
  • There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to Temixys during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263.
  • Women with HIV-1 infection should not breastfeed because HIV-1 can be passed to the baby in the breast milk

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Summary

Temixys (lamivudine and tenofovir disoproxil fumarate) is a medication used in combination with other antiretroviral agents to treat human immunodeficiency virus type 1 (HIV-1) infection in adult and pediatric patients weighing at least 35 kg. Serious side effects of Temixys include severe acute exacerbations of hepatitis B, new or worse kidney problems (including kidney failure), changes in your immune system (Immune Reconstitution Syndrome), and others.

Treatment & Diagnosis

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Medically Reviewed on 6/16/2021
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All sections courtesy of the U.S. Food and Drug Administration