The risk of HIV transmission following needlestick injury involving contaminated blood is estimated at about 0.4%. (1)
There is evidence that the use of zidovudine prophylaxis reduces this risk by about 80% (1). Prophylaxis should be started, ideally, within 1-2 hours of exposure (1).
- drug regimen for post-exposure HIV prophylaxis
- antiretroviral agents from three classes of drug are currently licensed for first-line treatment of HIV infection, namely:
- nucleoside/nucleotide analogue reverse transcriptase inhibitors (NRTIs);
- non-nucleoside reverse transcriptase inhibitors (NNRTIs); and
- protease inhibitors (PIs)
- zidovudine (an NRTI) is the only drug to date which has been studied and for which there is evidence of a reduction in risk of HIV transmission following occupational exposure
- however, as no antiretroviral drug has been licensed for PEP, they can only be prescribed for PEP on an 'off-label' basis
- a suggested starter regimen (2):
- after due consideration of storage/stability issues, side effect profiles, drug interactions, drug resistance and regimen simplicity (i.e. reduced pill burden and food restrictions), the following regimen is now recommended for PEP starter packs:
- one Truvada tablet (245mg tenofovir and 200mg emtricitabine (FTC)) once a day
- plus Two Kaletra film-coated tablets (200mg lopinavir and 50mg ritonavir) twice a day
Notes:
- possible side effects:
- all of the antiretroviral agents have been associated with side effects. Many of these can be managed symptomatically. Side effects of the NRTIs (e.g. tenofovir and emtricitabine) include gastrointestinal (e.g. nausea, diarrhoea) as well as dizziness and headache. In clinical trials of Kaletra, the most commonly reported side effect was diarrhoea, followed by other gastrointestinal disturbances, asthenia, headache and skin rash
- treatment should be initiated as soon as possible ideally within hours and certainly within 48-72 hours of exposure for it to be effective. It is not generally recommended beyond 72 hours post exposure. PEP is continued for at least 28 days (3).
Follow up of all occupationally exposed healthcare workers should be undertaken and should include: counselling, post-exposure testing and medical evaluation whether or notthey have received PEP (3).
- patients should also be advised about seeking medical advice on any acute illness which may occur during this period. e.g. - rash, myalgia, fatigue, malaise or lymphadenopathy which may be due to seroconversion illness or may be caused by side effects of antiretroviral medication (3)
- according to EAGA recommendations the minimum follow up time should be at least 12 weeks after the HIV exposure event or, if PEP was taken, for at least 12 weeks from when PEP was stopped
- longer follow-up with additional testing may be necessary for complex cases (3)
Reference: