Clinician contributions Emergency General Practice Infectious Disease Sexual Health


Dr Stephanie Rea provides a summary of PEP relevant to junior doctors. Steph’s article is supported by Dr Darren Russell and Dr Eugene Priscott from Sexual Health, and Dr Trent Yarwood, an infectious disease specialist in TNQ.


What is it

Post Exposure Prophylaxis (PEP) is triple or double antiretroviral therapy that can be given as a one-month course within 72 hours of possible HIV exposure.

The medication is stocked in most emergency departments including Cairns Hospital and can also be accessed through Cairns Sexual Health service.


Who is at risk

In Australia HIV is most commonly transmitted through anal intercourse in the MSM (Men who have Sex with Men) population.

However, it is also important to consider vaginal intercourse as alternative means of transmission. This may include potential exposure with a contact who may be HIV positive, is from a high risk country, or who is known to engage in high risk behaviours (e.g. multiple sexual partners from a high-risk country, or IDU). Most recently in Cairns and Far North Queensland there has been a rise in HIV within the Aboriginal and Torres Strait Islander population. Thus, in this current climate, FNQLD Clinicians may also consider young ATSI patients at high risk.

HIV cannot be transmitted by being spat on. People presenting concerned about the risk of HIV transmission in this scenario need counselling and reassurance. In Australia the risk following a needlestick injury in the community is negligible. PEP is generally not indicated in this circumstance. Discuss these patients with the Infectious diseases team or Sexual Health. If you cannot get in touch with them it is recommended you commence PEP but explain that specialist doctors will further discuss the risks and need for treatment with them.

The Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) estimates the following risk of HIV transmission based on the type of exposure. This risk estimate is based on unprotected sex or assumed condom failure.

PEP table


 Locating PEP & Timing

There should not be a delay in providing PEP to patients who have possibly been exposed to HIV. It must be given within 72 hours of the exposure to be effective.

The emergency department at Cairns Hospital routinely stocks at least 3 “PEP packs” at any time. These can be located in the pharmacy store area of the orange section. This pack provides enough medication for 3 days of the one month course. The remainder of the course can be accessed through Cairns Sexual Health Service.



A thorough sexual history should be taken. Pertinent questions include the type of sex, time of exposure and details of the contact including country of origin and HIV status if known. It may be useful to ask if the patient has taken PEP previously to identify if they have experienced past side effects. People who benefit from PEP may be a candidate for PrEP (pre-exposure prophylaxis – this can be initiated by Cairns Sexual Health Service). Investigations should include screening for other STIs – FCU/Swabs for chlamydia and gonorrhoea, and testing for other Blood Borne Viruses/STIs (Hepatitis B and C, and syphilis). Inexperienced clinicians may find counselling on HIV prior to initiation of PEP a daunting task. Important points to explain in the emergency department include possible risk of transmission based on exposure (see above ASHM table), the success rate of PEP if taken correctly (over 85%), how to take the PEP medication, and warning of common side effects and when they should follow up with Cairns Sexual Health Service (within 3 days). If the clinician or patient have further questions please contact the Infectious Diseases team or Cairns Sexual Health Service where specialist staff are readily accessible and only a phone call away!

In 2016 with the current antiretrovirals available in Australia, many HIV positive patients can live long, happy and unaffected lives with an undetectable viral load. However, prevention is better than cure and clinicians are encouraged to promote PEP amongst at risk patients.


Follow up

It takes between 4-6 weeks following exposure before HIV antigen/antibody testing can be done. It is important that at risk patients are not lost to follow up. All patients commenced on PEP at Cairns Hospital should be referred to Cairns Sexual Health Service (patient details send via Fax 4226 4771, Phone (07) 4226 4769 or Email ) once they have received their PEP starter pack.

1 Comment

  • Thanks Steph!
    What are the common and severe side effects that you would discuss with patients prior to commencing PEP? And a follow up, at what risk level (eg 1/500, 1/1000) would you suggest the risks outweigh the benefit of PEP? For example, say a circumcised MSM comes into ed 24/24 after unprotected insertive anal intercourse with someone he knows to be “a real party boy” but no known HIV+ history: would you commence PEP in this situation?
    – Alex.

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