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Pre-exposure prophylaxis (PrEP) is a medication taken by people who don’t have HIV (human immunodeﬁciency virus) to reduce their risk of getting HIV.
PrEP involves taking a single tablet which is a combination of two anti-retroviral medications called tenofovir and emtricitabine.
PrEP is taken before any potential exposure to HIV. There are two ways to take PrEP:
- Daily dosing – One tablet is taken every day.
- On demand dosing (only suitable for some people, discuss with your health professional if this method is suitable for you) – Two tablets are taken between 2-24 hours prior to potential exposure to HIV, followed by a third tablet 24 hours after the ﬁrst dose and a fourth tablet 48 hours after the ﬁrst dose.
Daily dosing with PrEP is 95-99% effective at preventing HIV. On demand dosing is less effective at preventing HIV, at 86-95%.
PrEP always needs to be taken as prescribed by your health professional in order to be effective.
PrEP may be available to those who think they need extra protection against HIV, and is recommended for people who:
- have anal sex with multiple partners, without using condoms.
- share injecting equipment.
- have sex with someone who is HIV positive and who has a detectable viral load.
- have a high level of concern about the potential risk of contracting HIV, affecting their quality of life.
- do not use condoms consistently.
Your health professional will assess your level of risk to determine if PrEP is suitable for you.
Most doctors and some nurse practitioners can prescribe PrEP but it is best to see someone who is an experienced prescriber. Doctors at SHQ can prescribe PrEP, or can refer you to a suitable health professional in your area.
At your ﬁrst appointment, your health professional will discuss whether PrEP is suitable for your individual circumstances. They will do the following:
- a risk assessment to determine your level of risk.
- a full medical history.
- screening for sexually transmissible infections (STIs) including HIV.
- screening for blood-borne viruses such as hepatitis and syphilis.
- tests for kidney function.
It is very important to get tested for HIV before starting PrEP. If you are HIV positive, this medication alone is not effective enough to treat the virus, and may limit your future treatment options.
If PrEP is suitable for you, your health professional will provide you with a prescription for a three-month supply.
Once you have started PrEP, you will need to be reviewed and STI/BBV tested every three months to ensure that PrEP is still suitable for you.
- PrEP is considered to be a safe medication when monitored and used correctly.
- PrEP does not prevent the transmission of other STIs, so consistent condom use and regular STI testing are recommended.
- PrEP is accessible on the PBS from most pharmacies, so a month’s supply will cost around $40 if you have a Medicare card or under $10 if you have a concession card. PrEP is still available for those without a Medicare card but this may involve us helping you to safely import it from overseas.
- You may experience some side effects including headaches, nausea, fatigue and abdominal pain. These side effects should subside over time and may be less if PrEP is taken at night.
- There is a small risk of kidney damage when taking PrEP, so testing your kidney function every six months is recommended.
- HIV testing and a follow up appointment with your health professional is required every three months.
- If you want to stop taking PrEP, discuss this with your health professional.
- If you think you have been exposed to HIV and are not on PrEP, you may want to consider Post-Exposure Prophylaxis, or PEP. To access PEP or learn more, visit getpep.info
If you have any questions about PrEP, please contact our Sexual Health Helpline.
The Australasian Society of HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) PrEP Guidelines Update. Prevent HIV by Prescribing PrEP. Sydney, 2019
Information last updated August 2023