Infectious Diseases · Pathway 67
Post-Exposure Prophylaxis
Key points
- Hepatitis A: human normal immunoglobulin (HNIG) or hepatitis A vaccine, depending on the exposure and timing.
- Hepatitis B: if the source is HBsAg-positive, give a booster to known vaccine responders; for non-responders or unknown status give hepatitis B immunoglobulin (HBIG) plus an accelerated vaccine course (see the Green Book).
- Hepatitis C: no vaccine or immunoglobulin - monitor with PCR; if seroconversion occurs, refer for direct-acting antiviral treatment (interferon/ribavirin is no longer used).
- HIV PEP (UK guideline for the use of HIV post-exposure prophylaxis 2021, BASHH-led and BHIVA co-badged): start as soon as possible, PREFERABLY WITHIN 24 HOURS, and it can be considered UP TO 72 HOURS after exposure · continue for a minimum of 28 DAYS.
- First-line regimen: TENOFOVIR DISOPROXIL 245 mg / EMTRICITABINE 200 mg fixed-dose combination PLUS RALTEGRAVIR 1200 mg ONCE DAILY · the full 28-day course should be given at first attendance rather than a short starter pack, because starter packs reduce completion · avoid antacids containing aluminium, magnesium or calcium, plus multivitamins and iron, with once-daily raltegravir.
- In pregnancy or where pregnancy is possible, RALTEGRAVIR 400 mg TWICE daily is preferred (with tenofovir disoproxil/emtricitabine) · pregnancy and breastfeeding should NOT alter the decision to offer PEP · take a baseline pregnancy test in women of childbearing age.
- FOLLOW-UP TESTING: final HIV test at a minimum of 45 DAYS after the PEP course is COMPLETED — so at least 73 days (about 10.5 weeks) after the exposure if the full 28-day course was taken · for sexual exposures this is often done at 12 weeks to align with syphilis testing.
- Baseline screening: sexual exposure also warrants chlamydia, gonorrhoea and syphilis testing, with hepatitis C screening in MSM and others at risk; occupational exposure warrants hepatitis C screening in all · consider the source's risk and HIV viral suppression, and consider tetanus and other exposure-specific prophylaxis.