emtricitabine + tenofovir disoproxil succinate: clinical use

Prescribing considerations

• For HIV treatment, use only as part of combination antiretroviral therapy under an experienced clinician.
• For PrEP, confirm HIV-negative status and assess possible acute HIV infection before initiation.
• Establish hepatitis B status and plan withdrawal carefully because severe hepatitis flares can occur.
• Assess renal and bone risk, including kidney disease, osteoporosis, fractures and concurrent nephrotoxins.
• PrEP does not replace broader prevention measures or screening for other sexually transmitted infections.

Contraindications and cautions

• Hypersensitivity to either active substance or an excipient.
• Use as PrEP when HIV-1 status is positive or unknown.

Monitoring

• Assess creatinine clearance and serum phosphate before use and periodically thereafter, with closer monitoring for renal risks or interacting medicines.
• During PrEP, repeat HIV testing regularly and investigate symptoms compatible with acute HIV infection.
• Monitor for proximal tubulopathy, declining renal function and relevant bone symptoms.
• After withdrawal in someone with hepatitis B, arrange clinical and laboratory follow-up for hepatic exacerbation.

Clinical pharmacology

Emtricitabine is a cytidine nucleoside analogue; tenofovir disoproxil is a prodrug converted to the adenosine nucleotide analogue tenofovir. Their phosphorylated metabolites inhibit HIV reverse transcriptase and terminate viral DNA chains. Both are predominantly eliminated renally, and CYP-mediated interaction potential is low.

Formulation and product differences

• The selected product is a blue, capsule-shaped film-coated tablet containing lactose.
• It may be disintegrated in water, orange juice or grape juice and taken immediately.
• It is supplied in moisture-protective bottles containing a desiccant canister, which must remain in the bottle and must not be swallowed.

Tablet

Route: Oral

Strengths: 200 mg + 245 mg