Antiretroviral Agent: Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) with specific activity against the Human Immunodeficiency Virus Type 1 (HIV-1).
Pediatric Formulation: The 200 mg tablet is a specific dosage strength formulated for pediatric patients, with the dose determined based on the child’s body weight. It is not intended for use as monotherapy.
Combination Therapy Component: It is always used in combination with at least two other antiretroviral agents from different drug classes to form a complete and effective treatment regimen.
Film-Coated Tablet: The tablet is film-coated, and should not be crushed, broken, or chewed. For children who cannot swallow tablets, alternative formulations like capsules or sprinkles may be available.
Advantages
Weight-Based Dosing: The 200 mg strength is a crucial component for achieving accurate weight-based dosing in pediatric patients, which is essential for efficacy and safety.
Once-Daily Regimen: Efavirenz has a long half-life, allowing for once-daily dosing. This simplifies the treatment regimen for children and their caregivers, leading to improved adherence.
High Barrier to Resistance: As part of a combination regimen, Efavirenz has a high barrier to resistance, which helps maintain the long-term effectiveness of the therapy.
Established Efficacy: This drug is a well-established and highly effective component of first-line antiretroviral therapy (ART) regimens for children in many parts of the world.
Uses
Pediatric HIV-1 Infection: Indicated for the treatment of HIV-1 infection in pediatric patients who are at least 3 months old and weigh at least 3.5 kg, as part of a combination regimen.
First-Line Therapy: It is a common and recommended component of first-line antiretroviral therapy for children due to its potent antiviral activity and convenient once-daily dosing.
Pre-Exposure and Post-Exposure Prophylaxis: In certain situations, Efavirenz may be used as a component of pre-exposure (PrEP) or post-exposure prophylaxis (PEP) regimens in adolescents.
Part of Fixed-Dose Combinations: The 200 mg dose is often co-formulated with other NRTIs (like Tenofovir and Lamivudine) in a single tablet to further reduce pill burden and improve adherence.
Nature
NNRTI Class: Efavirenz belongs to the non-nucleoside reverse transcriptase inhibitor (NNRTI) class of drugs.
Mechanism of Action: Unlike NRTIs, Efavirenz does not require intracellular phosphorylation to become active. It binds directly to a specific site on the HIV-1 reverse transcriptase enzyme, causing a conformational change that inactivates the enzyme and blocks viral DNA synthesis.
Inhibition of Viral Replication: By inhibiting reverse transcriptase, Efavirenz prevents HIV’s genetic information from being converted from RNA to DNA, thereby halting a crucial step in the viral replication cycle.
Metabolism & Side Effects: Efavirenz is primarily metabolized by liver enzymes (CYP450 system) and can cause central nervous system (CNS) side effects like dizziness, abnormal dreams, and impaired concentration. Taking the medication at bedtime on an empty stomach can help minimize these effects.
Storage
Temperature: Store Efavirenz tablets at a 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.
Administration: It is recommended to administer the tablet on an empty stomach, preferably at bedtime, to improve the tolerability of nervous system side effects.
Child Safety: Store the medication in a secure location, out of the reach of children and pets.
