Jiweijiu Nevirapine Zidovudine and Lamivudine Tablets

1. Indications and Usage
HIV-1 Infection: Indicated for the treatment of Human Immunodeficiency Virus type 1 (HIV-1) infection in adults.
Combination Therapy: It is a fixed-dose combination of three antiretroviral agents and should be used as part of a comprehensive antiretroviral regimen. It is not indicated for monotherapy.
2. Dosage and Administration
Recommended Dosage: One tablet taken orally once daily.
Mandatory Lead-in Phase: To reduce the risk of severe rash and hepatotoxicity, a lead-in phase is required. For the first 14 days, the dose must be reduced to one tablet every 24 hours (or half the standard daily dose). Starting at the full recommended dose is contraindicated.
Administration Details: After the 14-day lead-in period, the dose is increased to the full recommended dosage of one tablet once daily. The tablet should be swallowed whole and can be taken with or without food.
Renal/Weight Considerations: The fixed-dose combination is generally not recommended for patients with significant renal impairment or low body weight, as they may not receive adequate dosing of all three components.
3. Mechanism of Action
Nevirapine (NNRTI): Binds directly and non-competitively to the HIV-1 reverse transcriptase enzyme, causing a conformational change that inhibits the enzyme’s activity and stops viral DNA synthesis.
Zidovudine (NRTI): A thymidine analogue that, upon intracellular phosphorylation to its active triphosphate form, competitively inhibits reverse transcriptase and terminates the growing viral DNA chain.
Lamivudine (NRTI): A cytidine analogue that, after phosphorylation to its triphosphate form, inhibits reverse transcriptase and causes chain termination during HIV and HBV DNA synthesis.
4. Safety and Warnings
Hepatotoxicity: Severe, life-threatening, and fatal hepatotoxicity and hepatitis have been reported, particularly within the first 6 to 18 weeks of treatment. Liver function must be monitored closely.
Severe Rash: Serious and sometimes fatal rash, including Stevens-Johnson syndrome (SJS) and toxic skin eruptions, are common adverse events. The risk is highest during the initial lead-in period.
Immune Reconstitution Inflammatory Syndrome (IRIS): In patients with advanced HIV, the restoration of the immune system may cause an inflammatory response to latent opportunistic infections.
Lactic Acidosis/Severe Hepatomegaly: NRTIs carry a warning for lactic acidosis and severe hepatomegaly with steatosis, which can be fatal.
5. Adverse Reactions and Clinical Research
Most Common Adverse Reactions: Rash, nausea, diarrhea, headache, fatigue, abdominal pain, and insomnia.
Hematologic Toxicity: Zidovudine is associated with bone marrow suppression, leading to anemia and neutropenia.
Clinical Research: Clinical trials demonstrated that this triple-combination regimen significantly reduces plasma HIV-1 RNA levels and increases CD4+ T-cell counts compared to baseline.
6. Drug Interactions
CYP3A4 Substrates/Inducers: Nevirapine is a CYP3A4 inducer and can reduce plasma concentrations of co-administered drugs (e.g., certain azole antifungals, opioids, or other antiretrovirals).
NRTI Interactions: Concurrent use of stavudine or didanosine with zidovudine is contraindicated due to antagonistic effects and increased toxicity.
Other NRTIs: Do not administer with other nucleoside analogues without careful evaluation of overlapping toxicities.
7. Pharmaceutical Information
Chemical Composition: Active ingredients: Nevirapine, Zidovudine, and Lamivudine.
Appearance: Hard capsule or tablet (depending on specific formulation) containing the fixed doses of the three active ingredients.
Packaging: Typically supplied in blisters or bottles.
Storage: Store at controlled room temperature (20°C to 25°C). Protect from moisture and light.