Vemlidy vs Viread

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For patients with chronic hepatitis B, certain antiviral drugs can aid in reducing the virus's activity within the body and prevent further liver damage. Vemlidy (Tenofovir alafenamide) and Viread (Tenofovir disoproxil fumarate) are two such medications that are prescribed to treat chronic hepatitis B infections. Both of these drugs work by inhibiting the viral reverse transcriptase enzyme, thus preventing viral replication and reducing the amount of virus in your body. Although both have similar mechanisms of action, they differ significantly in their impact on kidney function and bone health. Vemlidy has a more targeted delivery mechanism into hepatic cells which results in less drug exposure for kidneys and bones; whereas, Viread is associated with a higher risk of renal impairment and decreased bone mineral density over time.

What is Vemlidy?

Tenofovir Alafenamide (the generic name for Vemlidy) is a potent drug in the antiretroviral class that was introduced as an alternative to Tenofovir Disoproxil Fumarate (Viread). This marked a significant advancement from the previous generation of medications used to treat Hepatitis B and HIV. The FDA first approved Vemlidy in 2016. It works by blocking reverse transcriptase, an enzyme integral to viral replication, effectively reducing the amount of virus in the body while increasing CD4 cell count – indispensable white blood cells that fight infection. Vemlidy has a selective influence on this enzyme with only minor side effects compared to its predecessor, which results in it having fewer detrimental impacts on kidney function and bone density than other antiretroviral drugs like Viread that have stronger effects on these two aspects.

What conditions is Vemlidy approved to treat?

Vemlidy is approved for the treatment of chronic hepatitis B virus (HBV) infection in adults with compensated liver disease:

  • Chronic Hepatitis B, a viral infection that attacks the liver and can cause both acute and chronic diseases
  • Compensated Liver Disease, where the liver is damaged but still capable of performing most of its functions.

On the other hand, Viread has a broader application as it is used to treat HIV infections as well in addition to treating chronic HBV.

How does Vemlidy help with these illnesses?

Vemlidy is designed to manage chronic hepatitis B by inhibiting the action of certain enzymes related to the replication of the Hepatitis B virus within liver cells. It does this by preventing these enzymes from synthesizing new DNA strands, thus halting viral multiplication and reducing viral load in the body. DNA is a type of molecule that carries genetic instructions for growth, development, functioning and reproduction in all known living organisms and many viruses. People with chronic hepatitis B have an overactive form of this virus. Therefore, by blocking its replication process, Vemlidy can limit the negative effects of a high viral load and help patients manage their condition more effectively.

What is Viread?

Viread, also known as tenofovir disoproxil, is an antiviral medication that hinders the activity of a certain virus in your body. It is most commonly used for treating chronic hepatitis B and HIV infections where it works by blocking reverse transcriptase, an enzyme these viruses need to reproduce in the body. The drug was first approved by the FDA in 2001.

Unlike its counterpart Vemlidy (tenofovir alafenamide), Viread does not selectively target specific cells which means it has a broader range of action but can potentially cause more side effects. These include nausea, vomiting, diarrhea and gas while severe side effects such as kidney problems are less common.

The choice between Viread and other antivirals like Vemlidy often comes down to individual patient factors including their overall health status and response to treatment.

What conditions is Viread approved to treat?

Viread is approved by the FDA for certain specific treatments, including:

  • Chronic Hepatitis B (HBV), an infectious liver disease that can cause severe health problems if not treated
  • In conjunction with other antiretroviral drugs to manage Human Immunodeficiency Virus 1 (HIV-1) in adults and pediatric patients two years of age and older.

How does Viread help with these illnesses?

Viread, like Vemlidy, is an antiviral medication that prevents human immunodeficiency virus (HIV) or hepatitis B virus cells from replicating in the body. It works by inhibiting the action of a viral enzyme called reverse transcriptase, which plays a key role in the replication process of these viruses. Viread's ability to disrupt this cycle helps limit the spread of infection and aids in managing symptoms. However, unlike Vemlidy which has a tenofovir alafenamide base, Viread contains tenofovir disoproxil fumarate which can potentially lead to more side effects for patients such as kidney problems and bone loss over time. Despite this factor, it remains commonly prescribed due to its efficacy against both HIV and chronic Hepatitis B infections where resistance has developed towards other medications.

How effective are both Vemlidy and Viread?

Both tenofovir alafenamide (Vemlidy) and tenofovir disoproxil fumarate (Viread) have established histories of success in treating patients with chronic hepatitis B, and they were initially approved by the FDA within a span of 15 years. Both drugs are from the same class, acting as nucleotide analogue reverse transcriptase inhibitors. The efficacy of Vemlidy and Viread in suppressing viral replication was directly studied in several clinical trials; the two drugs exhibited similar efficacy in managing viral load as well as similar safety profiles.

A review focused on Vemlidy demonstrated its effectiveness at reducing viremia levels even after only a few weeks into treatment; additionally, it showed fewer renal-related side effects compared to some other antiviral medications due to its ability to deliver higher intracellular concentrations while keeping plasma concentration low. This means that it is also suitable for use across different populations including those with renal impairments.

On the other hand, multiple studies have shown that Viread is an effective first-line therapy for chronic hepatitis B infection. Nonetheless, longer-term use has been associated with renal toxicity and bone density loss due to high systemic exposure following oral administration. Furthermore, although both Vemlidy and Viread show good tolerability profile overall, data suggests that patients taking Vemlidy experience fewer gastrointestinal symptoms than those taking Viread.

abstract image of a researcher studying a bottle of drug.

At what dose is Vemlidy typically prescribed?

Oral dosages of Vemlidy are typically 25 mg/day, which is found to be effective in treating chronic hepatitis B virus (HBV) infection in most people. For adults and adolescents who weigh at least 35 kg, the dosage can start with this amount. If there's no response after a few weeks, the doctor may reassess the treatment plan rather than increase the dosage due to potential side effects. The maximum daily dose that should not be exceeded is 25 mg/day for Vemlidy. On the other hand, oral doses of Viread often range between 245 -300 mg/day for adults and adolescents weighing at least 35 kg when used to treat HBV infections or HIV-1 infection.

At what dose is Viread typically prescribed?

Viread treatment is typically initiated at a dosage of 300 mg/day taken orally once daily for the management of chronic hepatitis B and HIV-1 infection. The tablet should be swallowed whole without crushing, with or without food. If after several weeks there's no distinct improvement in patient condition, your healthcare provider may review this dosage but it's crucial to note that exceeding the recommended dose could potentially lead to renal impairment or other adverse effects. In patients with renal impairment, dosing intervals and monitoring frequency may need adjustment as directed by your doctor.

What are the most common side effects for Vemlidy?

While both Vemlidy and Viread are used to treat chronic hepatitis B, they can have differing side effects. Common milder side effects of Vemlidy include:

  • Headache
  • Abdominal pain
  • Fatigue (general weakness and tiredness)
  • Nausea
  • Diarrhea
  • Dyspepsia (burning, discomfort, or pain in the digestive tract)
  • Cough

On the other hand, common side effects with Viread may also include:

  • Rash
  • Pain
  • Depression -Vomiting -Dizziness

If any of these side effects persist or worsen while taking either medication, it is advisable to seek medical attention promptly.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Vemlidy?

When choosing between Vemlidy and Viread, it's important to consider potential side effects. For both medications, these might include:

  • Signs of lactic acidosis: unusual muscle pain or weakness; trouble breathing; stomach pain with nausea, vomiting or fast heartbeat
  • Symptoms indicating new or worsening liver problems: loss of appetite for several days or longer; nausea; lower abdominal pain and discomfort; dark urine; yellowing skin or whites of the eyes
  • Unusual changes in mood including thoughts about suicide
  • Signs of allergic reaction such as difficulty breathing, swelling of your face, lips, tongue throat
  • Kidney issues signaled by urination changes (increased/decreased frequency), extreme exhaustion, skin color changes
  • Bone complications like bone pain without injury or fractures

Always remember that this is not an exhaustive list and you should consult your healthcare provider if you experience any distressing symptoms while taking either medication.

What are the most common side effects for Viread?

Although both Vemlidy and Viread are antiviral medications used to treat chronic hepatitis B, they come with different side effects. When taking Viread, patients may experience the following:

  • Nausea or vomiting
  • Diarrhea
  • Headache or dizziness
  • Difficulty sleeping (insomnia)
  • Itchy or rash-prone skin
  • Depression, anxiety, and other mood changes -Muscle pain or joint aches.

Additionally, some people have reported weight loss while on this medication. In rare cases, users might also notice a rapid heartbeat. It's important to note that these potential side effects do not occur in everyone who takes the medication; however, if you notice any significant changes after beginning treatment with Viread, contact your healthcare provider immediately for advice.

Are there any potential serious side effects for Viread?

While Viread is generally well-tolerated, it can sometimes cause serious side effects. These may include:

  • Signs of an allergic reaction: hives; difficulty breathing; swelling of the face, lips, tongue or throat
  • Lactic acidosis - a metabolic disorder characterized by weakness or tiredness, unusual muscle pain, trouble breathing, stomach pain with nausea and vomiting, slow or irregular heart rate
  • Kidney problems - little or no urination; painful or difficult urination; swelling in your feet or ankles
  • Liver problems - loss of appetite, upper stomach pain spreading to your back with nausea and vomiting; dark urine
  • Severe lower back pain Please consult your healthcare provider immediately if you observe any signs of these potential adverse reactions while taking Viread.

Contraindications for Vemlidy and Viread?

Both Vemlidy and Viread, like most antiviral medications, may exacerbate symptoms of certain concurrent conditions in some people. If you notice an increase in the severity of your existing health problems or experience severe side effects such as lactic acidosis (a severe build-up of lactic acid), hepatomegaly (enlarged liver) with steatosis (fatty liver), please seek immediate medical attention.

Neither Vemlidy nor Viread should be taken if you are using or have recently used other drugs that could potentially harm your kidneys. Always inform your physician about any medications you're currently taking; some medicines require a washout period to prevent harmful interactions with both Vemlidy and Viread.

Furthermore, patients infected with HIV-1 should not use these two drugs unless they're also receiving specific treatments for HIV-1 because this might lead to reduced effectiveness and potential development of resistant strains. These patients must consult their healthcare providers before initiating treatment.

How much do Vemlidy and Viread cost?

For the brand name versions of these drugs:

  • The price of a 30-tablet supply of Vemlidy (25 mg) averages around $1,800, which works out to approximately $60/day.
  • The price for a 30-tablet supply of Viread (300 mg) is about $1,500, working out to approximately $50/day.

Thus, if you compare on the basis of daily treatment cost alone, then Viread is less expensive than Vemlidy. However, it's important to remember that cost should not be the primary consideration in determining which drug is right for you.

As for generic versions: as far as I'm aware at this point in time there are no approved generics available either for tenofovir alafenamide fumarate (Vemlidy) or tenofovir disoproxil fumarate (Viread). This may change over time and prices could significantly decrease once generics become available.

Popularity of Vemlidy and Viread

Tenofovir alafenamide, also known by the brand name Vemlidy, was estimated to have been prescribed to about 180 thousand people in the US in 2020. Vemlidy accounted for approximately 3% of antiviral prescriptions in the US for Hepatitis B. It is a pro-drug and novel formulation of tenofovir designed to more efficiently target cells infected with hepatitis B virus than its predecessor drug Tenofovir disoproxil fumarate (TDF), marketed as Viread.

Viread, on the other hand, has been available longer and was prescribed to over one million people in USA during the same period. This accounts for around 20% of all antiviral prescriptions specifically targeted towards treating Hepatitis B. The prevalence of Viread has remained steady over recent years whereas that of newer medications like Vemlidy is steadily increasing as it provides similar efficacy with less kidney toxicity and bone density loss compared to TDF.


Both Vemlidy (Tenofovir Alafenamide) and Viread (Tenofovir Disoproxil Fumarate) have long-established usage in patients with chronic Hepatitis B, supported by numerous clinical trials indicating that they are more effective than placebo treatments. Both drugs may be considered for use, although their different chemical structures result in different pharmacokinetic properties. Tenofovir alafenamide is typically absorbed into the cells more efficiently, leading to less drug exposure and potentially fewer side effects compared to tenofovir disoproxil fumarate.

Viread has been on the market longer and is also used in HIV treatment plans besides Hepatitis B, whereas Vemlidy was approved specifically for Hepatitis B treatment. It's important to note that while both medications effectively suppress viral replication of Hepatitis B, neither one cures the disease.

Both drugs are available as brand-name products; however generics are only available for Viread at this time which could offer significant cost savings especially for those who must pay out-of-pocket.

The side effect profile differs between these two medications due to their distinct formulations. Both drugs can cause kidney problems but studies suggest that these occur less frequently with Vemlidy than with Viread. Additionally, loss of bone mineral density - another possible issue associated with long-term therapy - appears reduced when using Tenofovir Alafenamide compared to Tenofovir Disoproxil Fumarate.

Patients should closely monitor symptoms such as unusual fatigue or abdominal pain and seek immediate medical attention if severe symptoms arise like lactic acidosis or hepatomegaly with steatosis.