Nevirapin Viatris (Nevirapine)

Nevirapine is used in antiretroviral regimens targeting the HIV‑1 replication pathway.

• HIV‑1 infection (adults): reduces viral load when combined with other antiretrovirals.
• HIV‑1 infection (adolescents): achieves viral suppression as part of a recommended combination regimen.
• HIV‑1 infection (pregnant women): contributes to maternal viral control and reduces risk of mother‑to‑child transmission when included in a prescribed regimen.

• Nevirapine binds to a non‑nucleoside site on the HIV‑1 reverse transcriptase enzyme, inducing a conformational change that impairs the enzyme’s ability to transcribe viral RNA into DNA. This inhibition blocks the synthesis of proviral DNA, preventing integration of the viral genome into host cells and thereby halting replication of HIV‑1. The effect is achieved without competing with the natural nucleoside substrates.

Nevirapine may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Rash: mild to moderate skin eruption.
• Nausea: transient gastrointestinal discomfort.
• Fatigue: generalized tiredness.
• Headache: mild to moderate intensity.
• Abdominal pain: intermittent discomfort.

Serious or Rare Side Effects

• Stevens‑Johnson syndrome: severe skin reaction requiring immediate medical attention.
• Hepatotoxicity: elevated liver enzymes or clinical hepatitis.
• Severe hypersensitivity: fever, eosinophilia, and systemic symptoms.
• Anemia: marked reduction in hemoglobin levels.

When prescribing nevirapine, clinicians should observe several precautionary measures to ensure patient safety.

• Monitor liver function: perform baseline and periodic hepatic enzyme tests.
• Assess for rash: discontinue promptly if severe skin reactions develop.
• Avoid use with potent CYP3A inducers: drugs like rifampicin can lower nevirapine concentrations.
• Use caution in patients with hepatitis B or C: increased risk of liver injury.
• Store at room temperature (below 25°C): keep in the original packaging, protect from moisture.

Nevirapine interacts with several medicines through metabolic pathways, requiring attention to avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Rifampicin: strong CYP3A inducer that markedly reduces nevirapine plasma levels.
• St. John’s wort: herbal inducer of CYP enzymes leading to decreased nevirapine exposure.
• Protease inhibitors (e.g., ritonavir): can increase nevirapine concentrations and risk of toxicity.
• Efavirenz: additive central nervous system effects when combined.
• Alcohol: may potentiate hepatotoxic risk.

Moderate Interactions (Monitor Closely)

• Ketoconazole and other azole antifungals: may raise nevirapine levels, requiring liver monitoring.
• Warfarin: nevirapine can alter INR, necessitating dose adjustments.
• Oral contraceptives: nevirapine may reduce hormonal efficacy, advise alternative contraception.
• Nephrotoxic agents (e.g., aminoglycosides): monitor renal function and drug levels.
• Other NNRTIs: combined use may increase risk of adverse skin reactions.