Nevirapine Arrow Lab (Nevirapine)

Nevirapine is an NNRTI used in antiretroviral therapy to suppress HIV-1 replication and is incorporated into various treatment regimens.

• HIV-1 infection (treatment-naïve adults): Decreases plasma HIV-1 RNA levels when combined with other antiretrovirals, leading to immune recovery.
• HIV-1 infection (treatment-experienced patients): Provides an alternative option for patients with resistance to other drug classes.
• Prevention of mother-to-child transmission: Used in selected regimens to reduce the risk of vertical HIV transmission during pregnancy and delivery.

• Nevirapine binds to a non‑nucleoside site on the HIV‑1 reverse transcriptase enzyme, distinct from the nucleoside‑binding pocket. This binding induces a conformational change that impairs the enzyme’s polymerase activity, preventing the synthesis of viral DNA from the RNA template and thereby halting viral replication within infected cells. The inhibition is reversible and does not require intracellular phosphorylation, allowing rapid onset of antiviral effect after oral administration.

Nevirapine may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Rash: mild to moderate skin eruption, often pruritic.
• Nausea: transient gastrointestinal discomfort.
• Headache: mild to moderate intensity.
• Fatigue: general tiredness.
• Abdominal pain: mild discomfort in the stomach area.
• Dizziness: transient vertigo or light‑headedness.
• Diarrhea: loose stools, usually self‑limiting.
• Insomnia: difficulty falling or staying asleep.

Serious or Rare Side Effects

• Stevens‑Johnson syndrome: severe skin reaction with blistering and mucosal involvement.
• Hepatotoxicity: elevated liver enzymes, hepatitis, or liver failure.
• Severe hypersensitivity: fever, eosinophilia, and systemic symptoms.
• Neutropenia: marked reduction in white blood cells increasing infection risk.
• Liver failure: acute hepatic decompensation requiring medical intervention.

When prescribing Nevirapine, clinicians should observe several safety measures to minimize risks.

• Monitor liver function: obtain baseline transaminases and repeat periodically.
• Assess for rash: discontinue if severe skin reaction develops.
• Avoid co‑administration with potent CYP3A4 inducers: may reduce drug exposure.
• Use caution in patients with hepatitis B or C: increased risk of hepatic toxicity.
• Adjust dose in renal impairment if required by clinical judgment.
• Store below 25°C: keep in the original pack, protect from moisture.

Nevirapine interacts with several medicines through metabolic pathways, requiring careful management.

Major Interactions (Avoid)

• Rifampicin: strong CYP3A4 inducer that markedly lowers nevirapine levels.
• St. John’s wort: herbal CYP3A4 inducer reducing antiviral efficacy.
• Protease inhibitors boosted with ritonavir: may increase nevirapine concentrations and toxicity.
• Carbamazepine: enzyme inducer that can diminish nevirapine exposure.

Moderate Interactions (Monitor Closely)

• Efavirenz: co‑administration may increase hepatotoxic risk.
• Other NNRTIs (e.g., delavirdine): additive toxicity potential.
• Antacids containing aluminum or magnesium: may affect absorption if taken simultaneously.
• Fluconazole: moderate CYP inhibition that can raise nevirapine levels.