efavirenz + emtricitabine + tenofovir disoproxil succinate: clinical use

Prescribing considerations

• Initiation and switching should be supervised by a clinician experienced in HIV management.
• Confirm sustained virological suppression, treatment history and absence of clinically significant resistance.
• Assess renal, hepatic, psychiatric, cardiovascular, bone and pregnancy-related risks.
• The fixed combination is unsuitable when an individual component requires modification.
• Review hepatitis B status before stopping because withdrawal may trigger severe hepatitis exacerbation.

Contraindications and cautions

• Hypersensitivity to an active ingredient or excipient
• Severe hepatic impairment
• Specified congenital or acquired QT-prolongation risks, significant arrhythmia or severe electrolyte disturbance
• Concurrent use of specified QT-prolonging medicines, St John’s wort, voriconazole, elbasvir/grazoprevir and certain CYP3A4 substrates with potentially life-threatening toxicity

Monitoring

• HIV viral load and adherence
• Creatinine clearance and serum phosphate
• Liver function
• Mental health, sleep and neurological symptoms
• Bone symptoms and fracture risk where indicated
• Lipids and glucose
• Evidence of hepatitis flare after discontinuation in people with HIV and hepatitis B

Clinical pharmacology

Efavirenz is a non-competitive HIV-1 reverse-transcriptase inhibitor and induces CYP3A4, CYP2B6 and UGT1A1. Phosphorylated emtricitabine and tenofovir inhibit reverse transcriptase and terminate viral DNA chains. They are principally eliminated through the kidneys.

Formulation and product differences

• A fixed-combination, pink, capsule-shaped film-coated tablet.
• Components cannot be adjusted independently; separate preparations are needed for modification or selective discontinuation.
• The tablet uses tenofovir disoproxil succinate as the salt form.

Tablet

Route: Oral

Strengths: 600 mg + 200 mg + 245 mg