Abacavir Drug Profile

Introduction to Abacavir Drug Profile:  

Abacavir Drug Profile: Abacavir is an essential antiviral medication in the treatment of HIV. As a nucleoside reverse transcriptase inhibitor (NRTI), it works by reducing the amount of HIV in the body, helping prevent immune system damage. Understanding the abacavir drug profile is crucial for anyone considering it as part of their HIV treatment regimen, especially due to possible side effects and specific health warnings.

Drug Profile of Abacavir Overview

Detailed Explanation of Abacavir Drug

Chemical Structure:

• Molecular Formula: C₁₄H₁₈N₆O

Classification and Brands:

Abacavir is classified as an NRTI (Nucleoside Reverse Transcriptase Inhibitor) and is commonly used in HIV treatment. It is available under brand names such as

Ziagen, ABAMUNE, Abavir, and Abacor.

                              Abacavir

Category of Abacavir:

• NRTIs are a class of medications that block the action of reverse transcriptase, an enzyme crucial for HIV replication. By inhibiting this enzyme, NRTIs prevent the virus from copying its RNA into DNA, which is necessary for further infection and viral growth.

Dose:

600MG OD or 300MG BD

Pharmacokinetics of ABACAVIR:

• Abacavir is well absorbed with 83-90% bioavailability when taken orally. It reaches peak plasma concentration within 1-2 hours and distributes widely throughout the body, including the cerebrospinal fluid (CSF). The liver metabolizes the drug, and it is eliminated through the kidneys. Abacavir has a half-life of around 1.5 hours and does not require food adjustments.

Mechanism of Action (MOA):

• Abacavir works by converting into an active form, carbovir triphosphate, within the body. This active metabolite integrates into the HIV viral DNA, stopping replication by terminating the DNA chain elongation. Essentially, it disrupts the virus’s ability to replicate and spread, reducing the viral load in the body.

 Antiretroviral drugs’ mechanism in HIV Treatment

Indication:

• Doctors prescribe abacavir as part of combination therapy for HIV treatment. They never use it alone due to the risk of developing resistance; instead, they combine it with other antiretroviral drugs to ensure effectiveness.

Major Side Effects:

• Hypersensitivity Reaction: This is the most severe potential side effect, typically occurring within the first 6 weeks of treatment. Symptoms include fever, rash, gastrointestinal distress (like nausea, vomiting, and diarrhea), and respiratory issues (such as shortness of breath). Testing for the HLA-B*5701 genetic variant is recommended before starting Abacavir, as people with this variant are at higher risk for hypersensitivity reactions.
• Liver Toxicity: Some patients may experience liver damage, which can range from mild to severe. Regular monitoring of liver function is advised during treatment.
• Lactic Acidosis: Although rare, lactic acidosis is a serious side effect associated with all NRTIs. It involves a dangerous buildup of lactic acid in the bloodstream, which could lead to organ failure.
• Common Side Effects: These are generally mild and include fatigue and headaches. While not life-threatening, these can affect the quality of life for some patients.

Landmark Clinical Trials that you Need to Know in Abacavir Drug Profile

ABACUS Study (Abacavir Hypersensitivity and HLA-B*57:01 Testing)

• Objective: The ABACUS study investigated the importance of HLA-B*57:01 genetic testing to prevent hypersensitivity reactions in patients using abacavir. Abacavir hypersensitivity is a known risk, and this study aimed to establish how genetic screening could improve safety.
• Findings: The trial demonstrated that screening for the HLA-B*57:01 allele before starting abacavir therapy reduced the risk of life-threatening hypersensitivity reactions. This confirmed the value of genetic testing in safely prescribing abacavir to patients, making it a key recommendation in clinical practice for HIV treatment.

PAART Study (Paediatric Abacavir Antiretroviral Treatment)

• Objective: The PAART study focused on evaluating the safety and efficacy of abacavir in paediatric HIV patients, assessing its role in combination therapy for children with HIV.
• Findings: The study concluded that abacavir is both effective and safe for use in children, confirming its role in paediatric HIV care. It reinforced abacavir’s position as a trusted option in antiretroviral therapy for children, as part of a comprehensive HIV treatment plan.

References:

1. https://bnf.nice.org.uk/drugs/abacavir/
2. https://www.mayoclinic.org/drugs-supplements/abacavir-oral-route/description/drg-20061463
3. https://www.mayoclinic.org/drugs-supplements/abacavir-oral-route/description/drg-20061463