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Post-exposure Prophylaxis - HIV

Post-exposure prophylaxis (PEP) is a treatment that may prevent human immunodeficiency virus (HIV) infection and is available to anyone likely to have been exposed to HIV within the previous 72 hours. It is a combination of anti-HIV drugs that must be taken exactly as prescribed at very specific times over a four-week period.

PEP will reduce the risk of HIV infection following an exposure to infected blood or bodily fluids. In the case of occupational exposure in a workplace (e.g. needlestick injury in a clinic), PEP has been used for a number of years and has been effective in most cases. Studies have also shown the use of PEP to be effective in cases of non-occupational exposures (e.g. sex or sharing injecting equipment) in people who completed the full course of PEP.

PEP is not a guarantee that HIV infection will be prevented; it greatly decreases the chance of becoming infected. PEP will not make people immune to future HIV exposures. People still need to practise safe sex and in the case of people, who inject drugs safer injecting practices, as these remain the best ways to prevent HIV infection. This involves using condoms with water-based lubricant and the use of sterile injecting equipment at all times. If you are exposed to HIV again in the future you should seek urgent medical advice. Everyone has an equal responsibility in protecting themselves and their partners from contracting HIV.

Cause: 

A person who may have been exposed to HIV through contact with blood or body fluids from an HIV positive person via unprotected anal or vaginal intercourse (including condom breakage) with a partner who is HIV positive, or shared injecting equipment such as needles or syringes with a person who is HIV positive or unknown cause.

Treatment: 

It is extremely important that a person who may have been exposed to HIV through contact with blood or body fluids from an HIV positive person seeks medical advice as soon as possible. PEP may prevent infection in anybody who has engaged in unprotected anal or vaginal intercourse (including condom breakage) with a partner who is HIV positive, or shared injecting equipment such as needles or syringes with a person who is HIV positive. PEP is most effective when taken immediately after exposure to HIV, preferably within two hours - but it may still be effective if taken within 72 hours (3 days) from the time of exposure.

PEP must be prescribed by a doctor and is available from the clinics listed under help and assistance. Anyone wishing to access PEP should telephone one of the listed services for opening hours and advise them that PEP may be required. Don't feel anxious about discussing PEP with the trained clinical staff members of these services. The standard prescription drug co-payment will be charged by the pharmacy dispensing the drugs.

PEP consists of medications that can cause side effects such as abdominal pain, diarrhoea or headaches throughout the four week course of medication. Newer medications, though, are much less likely to cause these side-effects. Sticking to the strict medication routine is essential to give the treatments a chance to work effectively.

Even if the risk seems minimal or there is doubt about the need for PEP, discuss the matter with a doctor, either in a hospital emergency department, sexual health clinic or a GP. In addition, staff members from HIV services listed below are able to discuss your concerns and provide information about PEP.

A follow-up appointment with the doctor who prescribed PEP is essential after finishing the course of drugs so people can be tested for HIV.

Transmission: 

HIV may be transmitted when blood, semen or vaginal fluid from an infected person enters the body of an uninfected person. This can happen through:

  • Unsafe sex – rectal and vaginal
  • Sharing needles and injecting equipment contaminated with blood.

HIV may also be transmitted through donated blood products. However all blood, organs, tissues and semen donated in Australia are screened for HIV. The risk of getting HIV from these products in Australia is very low. Donating blood or body parts does not put you at risk of HIV infection.

Prevention: 
  • Everyone has a responsibility to protect themselves and their partners from contracting HIV. Practising safer sex by using condoms and water-based lubricant and safer injecting practices using sterile injecting equipment, remain the best ways to prevent HIV infection.
  • PEP is not a guarantee that HIV infection will be prevented
  • PEP will not make people immune to future HIV exposures. You will still need to practice safer sex and use safer injecting practices to prevent future HIV infection. If you are potentially exposed to HIV on another occasion in the future you should seek medical assistance to access PEP.
Other resources: 

Related content

Help and assistance: 

Specialist HIV support services:

  • Brisbane Sexual Health and HIV Service
  • Princess Alexandra Sexual Health
  • Bundaberg Sexual Health Clinic
  • Cairns Sexual Health Clinic
  • Gold Coast Sexual Health Clinic
  • Ipswich Sexual Health Service
  • Mackay Sexual Health Clinic & Sexual Assault Service
  • Mt Isa Sexual Health Service
  • Palm Island Sexual Health Service
  • Redcliffe Sexual Health and HIV Service
  • Rockhampton Sexual Health and HIV Service
  • Sunshine Coast –Wide Bay Sexual Health and HIV Service
  • Cape York, Northern Peninsula Area and the Torres Strait Islands Men’s and Women’s sexual health program
  • Toowoomba-Kobi House
  • Townsville Sexual Health Unit.

Departments of Emergency Medicine in all major urban and regional hospitals in Queensland.