Combination Antiretroviral: This tablet contains a fixed-dose combination of two active ingredients: Abacavir (A) 600 mg and Lamivudine (B) 300 mg.
Adult Dosage: This specific strength is formulated for adult patients, providing a standard daily dose of both medications in a single tablet.
NRTI Class: Both abacavir and lamivudine are classified as Nucleoside Reverse Transcriptase Inhibitors (NRTIs), a foundational class of drugs for managing HIV.
Not Monotherapy: This fixed-dose combination is not a complete regimen on its own. It is always used as part of a multi-drug regimen with at least one other antiretroviral agent from a different class to provide a complete and effective treatment plan.
Advantages
Improved Adherence: The fixed-dose combination of two drugs into a single tablet significantly reduces the overall pill burden, making the regimen easier for patients to follow and thereby improving medication adherence.
Synergistic Antiviral Effect: Both abacavir and lamivudine work together to suppress HIV replication, providing a powerful and effective therapeutic combination with a proven track record.
Simplified Dosing Schedule: The once-daily dosing of this single tablet simplifies the treatment schedule for patients, reducing the complexity of their regimen.
Efficacy and Tolerability: This combination is highly effective against HIV-1 and has a well-established safety and tolerability profile.
Uses
HIV-1 Infection: Indicated for the treatment of HIV-1 infection in adults and adolescents weighing at least 40 kg, as part of a combination regimen.
First-Line Therapy: It is a common component of first-line antiretroviral therapy (ART) regimens for adults, often combined with an integrase inhibitor to form a complete and potent treatment plan.
Treatment-Naïve and -Experienced Patients: The combination can be used in both patients who are new to antiretroviral therapy (treatment-naïve) and those who are treatment-experienced but have not developed resistance to these drugs.
Genetic Screening: A crucial prerequisite is that the patient must be tested and confirmed negative for the HLA-B*5701 allele to avoid a severe and potentially fatal hypersensitivity reaction to abacavir.
Nature
Nucleoside Reverse Transcriptase Inhibitors (NRTIs): Both abacavir and lamivudine are NRTI prodrugs that are converted to their active triphosphate forms inside the cell.
Mechanism of Action: Their active forms compete with natural nucleosides to be incorporated into the growing viral DNA chain. This leads to premature chain termination, which blocks the action of the viral enzyme reverse transcriptase.
Inhibition of Viral Replication: By inhibiting reverse transcriptase, both drugs prevent the transcription of the HIV RNA genome into DNA, thereby blocking a crucial step in the viral replication cycle.
Metabolism and Resistance: Both drugs are primarily eliminated by the kidneys. Resistance to the combination is reduced because two different mutations are needed for the virus to become resistant to both drugs simultaneously.
Storage
Temperature: Store the tablets at controlled room temperature, typically between 20∘C to 25∘C (68∘F to 77∘F).
Protection: Keep the tablets in their original, tightly closed container, protected from light and moisture.
Child Safety: Store the medication in a secure location, out of the reach of children and pets, as this is a potent medication.
Adherence: Patients must be educated on the importance of taking every dose as prescribed to prevent the development of viral resistance and to ensure long-term treatment success.
