Up to 1:8 Australian men who have sex with men has HIV infection.[23] High levels of adherence to daily co-formulated TDF/FTC has been shown to be highly effective at preventing HIV infection in populations at high risk of HIV acquisition (Table 11).[24]
It is estimated that 20% of gay men in Sydney are now taking PrEP the vast majority gaining access through ‘The expanded PrEP Implementation in Communities in NSW study’ (EPIC-NSW); an open-label implementation study of the use of co-formulated TDF/FTC to prevent HIV. The study ran from March 2016 and closed to recruitment in April 2018. Pre-exposure prophylaxis for HIV was then listed on the Pharmaceutical Benefits Scheme (PBS) on 1 April 2018. Pharmaceutical Benefits Scheme (PBS) subsidised PrEP prescription data outlined that between 1 April 2018 and 31 December 2023, 74,597 people (97.5% male) were dispensed PBS-subsidised PrEP at least once.[25]
PrEP using daily co-formulated TDF/FTC is approved by the Australian Therapeutic Goods Administration (TGA) and available through the Pharmaceutical Benefits Scheme (PBS). National PrEP Guidelines have been published.[26] In addition to access via implementation projects and the PBS, generic co-formulated TDF/FTC PrEP can be legally imported for personal use in Australia and is currently cheaper than the cost of a PBS prescription at $39.50/30 days for non concession card holders). Various websites offer access to PrEP via self-importation and some offer free access for those unable to afford PrEP via a coupon system e.g. PAN (PrEPaccessNOW) at: https://www.pan.org.au As with any on-line purchase, caveat emptor applies. Only reputable sites verified and recommended by AIDS organisations or established Australian PrEP providers should be used for on-line purchases.
Potential risks of PrEP
Daily co-formulated TDF/FTC used as part of an HIV risk-reduction strategy is not itself without risk, mainly to the kidneys and bones. Decreases in renal function have been documented, and occasional cases of acute renal failure, including Fanconi syndrome, have occurred among people with HIV infection using tenofovir (TDF) containing regimens.[27] An estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73m2 precludes daily use of co-formulated TDF/FTC as PrEP and 3-monthly check of renal function is recommended. People on daily co-formulated TDF/FTC should be advised against concurrent use nephrotoxic drugs for example, regular use of non-steroidal anti-inflammatory drugs.
Creatine supplements (thought to improve strength, increase lean muscle mass, and help the muscles recover more quickly during exercise) are commonly used by gay men and can cause an artefactual increase in serum creatinine with the commensurate drop in eGFR. Creatine supplementation use should be explored when assessing decreasing renal function in gay men on PrEP.
Decreases in bone mineral density (BMD) in the region of 3-4% have been observed in people with HIV infection treated with ART including tenofovir disoproxil fumarate-containing regimens.[28] Serial dual-emission X-ray absorptiometry (DEXA) scans on a subset of men who have sex with men in a randomised, placebo-controlled trial of Truvada PrEP trials determined that when comparing those persons randomised to receive PrEP medication and those randomised to receive placebo a small but statistically significant (approximately 1%) decline in BMD can occur during the first few months of PrEP which either stabilises or returns to normal.[8] There was no increase in fragility (atraumatic) fractures over the 1-2 years of observation in these studies. In contrast, in a small study of 34 men who have sex with men on daily Truvada as PrEP, about 50% had more than a 5% loss in BMD at one or more bone sites through 12 months of follow-up.[29] A lack of a control or placebo group and no data on other causes for low BMD mean that these data should be interpreted with caution but the results do raise the need for further investigation and education for those taking PrEP about maintaining good bone health.