VECTIBIX 20mg/ml Price

Overview

Welcome to Dwaey, specifically on VECTIBIX 20mg/ml page.
This medicine contains an important and useful components, as it consists of
Panitumumabis available in the market in concentration

Name

Adefovir Dipivoxil

Precaution

Adefovir dipivoxil is an antiviral medication primarily used for the treatment of chronic hepatitis B. Its use requires several important precautions: - **Pregnancy**: Adefovir dipivoxil is classified as a Category C drug in pregnancy, meaning that risk to the fetus cannot be ruled out. It should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Women of childbearing age should use effective contraception during treatment. - **Breastfeeding**: It is unknown whether adefovir is excreted in human breast milk. Therefore, the drug should be avoided in breastfeeding women unless the potential benefits outweigh the risks. Caution is advised when using this medication during breastfeeding. - **Renal Impairment**: Adefovir is primarily excreted through the kidneys, so patients with preexisting renal impairment may require a dose adjustment. It is essential to monitor renal function regularly, including serum creatinine and estimated glomerular filtration rate (eGFR), during treatment. - **Lactic Acidosis and Hepatomegaly**: Prolonged use of adefovir dipivoxil can be associated with lactic acidosis and severe hepatomegaly with steatosis. Although this is a rare complication, patients should be monitored for these conditions, especially those who have risk factors for liver disease or those co-infected with HIV. - **Resistance**: Prolonged use of adefovir dipivoxil may lead to the development of antiviral resistance, particularly when it is used alone for the treatment of hepatitis B. Therefore, combination therapy with other antiviral agents is often recommended.

Indication

Adefovir dipivoxil is primarily indicated for the treatment of **chronic hepatitis B** (CHB) in adults with evidence of active viral replication, elevated serum alanine aminotransferase (ALT) levels, and/or histologically active disease. - **Chronic Hepatitis B**: It helps to suppress viral replication, reduce liver inflammation, and decrease the risk of progression to cirrhosis and liver cancer. Adefovir is used in patients who are either nucleoside or nucleotide therapy-naive or who have failed previous therapy. - **Off-Label Uses**: While its use is primarily for hepatitis B, adefovir dipivoxil has occasionally been used off-label in the treatment of **HIV** in combination with other antiretroviral agents, though this is not its primary indication. Its efficacy in HIV is generally limited, and it is not recommended as a first-line therapy. - **HIV/Hepatitis B Coinfection**: Adefovir can be used in patients who are co-infected with HIV and hepatitis B, but it is not typically the preferred choice in these cases due to the availability of more effective drugs for both HIV and hepatitis B.

Contra indication

Adefovir dipivoxil is contraindicated in the following situations: - **Hypersensitivity**: Patients with a known hypersensitivity to adefovir or any components of the formulation should avoid using this medication. Allergic reactions can include rash, pruritus, and more severe reactions. - **Severe Renal Impairment**: Adefovir dipivoxil is contraindicated in patients with a creatinine clearance (CrCl) of less than 50 mL/min due to the potential for accumulation and toxicity. Dose adjustments are required in patients with renal impairment, and extreme caution is advised. - **Liver Cirrhosis and Acute Hepatic Decompensation**: Although adefovir is used to treat chronic hepatitis B, it is contraindicated in patients with acute hepatic decompensation or those with cirrhosis who are experiencing significant liver dysfunction. In these cases, other therapies may be more appropriate. - **HIV-Positive Patients with Hepatitis B**: While adefovir can be used in co-infected HIV/Hepatitis B patients, monotherapy is not recommended due to the risk of resistance in both HIV and hepatitis B viruses. It should only be used in combination with other HIV medications.

Side Effect

Adefovir dipivoxil may cause a range of side effects, both common and severe: - **Common Side Effects**: - Headache - Nausea - Diarrhea - Fatigue - Abdominal pain - **Serious Side Effects**: - **Renal Toxicity**: Adefovir is associated with nephrotoxicity, which can manifest as elevated serum creatinine, reduced glomerular filtration rate, or acute renal failure. Renal function should be regularly monitored during treatment. - **Lactic Acidosis**: Though rare, lactic acidosis is a severe side effect of adefovir, especially when used in combination with other antiviral drugs. Symptoms may include deep, rapid breathing, muscle pain, and tiredness. - **Hepatotoxicity**: Patients with chronic hepatitis B are at risk for exacerbation of liver disease, including liver failure, especially if treatment is discontinued suddenly. - **Bone Mineral Density**: Long-term use of adefovir can lead to reduced bone mineral density and an increased risk of fractures. - **Mitigating Side Effects**: Renal function, liver function, and bone health should be regularly monitored during therapy. Dose adjustments may be required for patients with renal impairment to avoid nephrotoxicity.

Pregnancy Category ID

3

Mode of Action

Adefovir dipivoxil is a **nucleotide analog reverse transcriptase inhibitor (NtRTI)**, which works by inhibiting the replication of the hepatitis B virus (HBV) through its action on the viral reverse transcriptase enzyme. - **Viral Replication Inhibition**: Adefovir is converted to adefovir diphosphate within cells. The active metabolite, adefovir diphosphate, competes with the natural nucleotide, adenosine triphosphate (ATP), for incorporation into the viral DNA strand during reverse transcription. Once incorporated, adefovir diphosphate causes chain termination, preventing the virus from completing its replication process and halting the production of new viral particles. - **Pharmacodynamics and Pharmacokinetics**: The drug has a long intracellular half-life, allowing it to have sustained antiviral activity even after a single dose. It is eliminated primarily through the kidneys, and its effects are dose-dependent. Regular dosing results in a significant reduction in HBV viral load and a decrease in liver inflammation and damage over time.

Interaction

Adefovir dipivoxil has several important drug interactions that need to be considered: - **Nephrotoxic Drugs**: The use of adefovir with other nephrotoxic drugs (such as NSAIDs, angiotensin-converting enzyme inhibitors, and diuretics) can increase the risk of renal toxicity. Monitoring renal function is critical when these drugs are co-administered. - **Other Antiviral Drugs**: When used with other antiviral agents like **tenofovir** or **lamivudine**, there is an increased risk of **renal impairment** and **lactic acidosis**. While these drugs may be used in combination, renal function must be closely monitored. - **Probenecid**: Co-administration of adefovir dipivoxil with **probenecid**, a drug that inhibits renal tubular secretion, may increase the plasma concentration of adefovir and its toxicities. Therefore, dose adjustments should be made, and renal function should be monitored. - **Zidovudine**: Co-administration of adefovir with **zidovudine** (a nucleoside reverse transcriptase inhibitor) can increase the risk of **mitochondrial toxicity**, especially in patients co-infected with HIV. - **Food and Alcohol**: Adefovir can be taken with or without food. While no significant food interactions are reported, alcohol should be avoided as it may exacerbate liver damage, especially in patients with chronic hepatitis B. Alcohol can also increase the risk of liver toxicity when combined with adefovir.

Pregnancy Category Note

Information not available

Adult Dose

- **Hepatitis B Treatment**: The recommended dose of adefovir dipivoxil for adults is **10 mg once daily**. This can be taken orally with or without food. Treatment should continue for at least 48 weeks to achieve optimal viral suppression and clinical response. - **Renal Adjustments**: In patients with moderate renal impairment (CrCl 30-49 mL/min), the dose should be reduced to 10 mg every other day. For those with severe renal impairment (CrCl less than 30 mL/min), the use of adefovir is generally contraindicated or should be done with extreme caution, requiring dose adjustments.

Child Dose

Adefovir dipivoxil is not approved for use in children under 18 years of age due to insufficient safety and efficacy data in this population. In clinical practice, a pediatric dose is not established. For those considering its use in pediatric patients with chronic hepatitis B, alternative antiviral therapies may be more appropriate.

Renal Dose

- **Moderate Renal Impairment (CrCl 30-49 mL/min)**: The dose should be reduced to **10 mg every other day**. - **Severe Renal Impairment (CrCl less than 30 mL/min)**: Adefovir dipivoxil is contraindicated, and alternative treatments should be considered. - **Dialysis**: Patients undergoing dialysis should also avoid the use of adefovir unless absolutely necessary, as dialysis can alter the drug's pharmacokinetics.

Administration

Information not available