Sexual Health / HIV/HIV pre-exposure prophylaxis

PrEP

also: pre-exposure prophylaxis · tenofovir/emtricitabine · Truvada · Descovy

Overview

Antiretroviral taken by HIV-negative people at risk, BEFORE exposure, to prevent acquisition. Highly effective when adherent.

Mechanism

Tenofovir disoproxil + emtricitabine (two NRTIs) maintain protective drug levels in genital/rectal mucosa so that any HIV transmitted cannot establish infection (reverse-transcription is blocked). Taken daily or "event-based" (2-1-1) for anal sex.

Indications

HIV-negative individuals at substantial risk of HIV (e.g. condomless sex with HIV+ partner not virally suppressed, MSM, serodifferent couples)

Adverse effects

Renal impairment (tenofovir DF)serious

Reduced bone mineral densitycommon

GI upset (early, settles)common

Cautions & contraindications

Undiagnosed/established HIV infectionall

Two-drug PrEP risks resistance — must EXCLUDE HIV first (and re-test 3-monthly).

eGFR <60 (tenofovir DF)renal

Interactions

Nephrotoxic drugs (NSAIDs)

Monitoring & kinetics

HIV test before and every 3 months,Renal function; STI screening; hepatitis B status

Oral, daily or event-based (2-1-1). Not protective against other STIs.

Choosing it

true

Source: BHIVA/BASHH — PrEP guidelines · BNF — Tenofovir/emtricitabine