A local infectious diseases specialist says HIV prevention drug Pre-Exposure Prophylaxis (PrEP) is a reasonable option for protecting New Zealand gay and bisexual men, who aren't using condoms, from HIV.
PrEP, under the brand Truvada, is used by people who are HIV-negative in order to reduce their risk of HIV infection.
Dr Massimo Giola from the Bay of Plenty DHB spoke at Body Positive's HIV Treatments Update Seminar this morning, reporting back on the discussions about the drug at the recent Australasian HIV/AIDS Conference.
He outlined the studies into its effectiveness which have been carried out around the world, particularly the iPrEx study which found it had 92 per cent efficacy among gay and bisexual men who fully adhered to the regime.
Overall the studies carried out have found PrEP to be most effective for men who have sex with other men, and least effective for heterosexual women.
Dr Giola said looking at all the data, "we can, I think, reasonably assume that PrEP with adherent [gay and bisexual men] taking at least four doses a week, is as effective as condoms in real life.
"Of course, condoms protect you also against STIs, something that PrEP doesn't do. But for men who are not willing, for any reason, to use condoms, PrEP is a more than reasonable option to protect them at least from HIV infection."
That's due to what happened in study into the on demand method, carried out among gay and bisexual men in France.
"Because those bloody French men had too much sex, they took an average number of 16 pills every month," Dr Giola explained.
He said under the regular use method, people take about four tablets a week anyway. "So if you divide 16 by four - that's four tablets a week ... so the guy who takes one on demand tablet a month, I'm not sure if he gets the same protection. That's an area that needs further investigation."
Auckland Sexual Health Service is leading a number of groups, including Body Positive and the New Zealand AIDS Foundation, in planning a PrEP demonstration project. It has been approved and work is underway on the protocol, but biggest barrier now is the fact they have no funding.
"Pharmac and the Ministry of Health have said 'do it, but don't expect any money from us'. Essentially that was the message," Dr Giola said.
Those organising the project are giving up their time and skills voluntarily. Dr Giola said they are hoping Gilead will provide the Truvada for free. If not, clients will have to cover the costs themselves, meaning the trial would be of limited scope.
Some New Zealanders have been asking their physicians for PrEP already. Truvada is not currently funded by Pharmac, and unfunded the retail price is in the vicinity of $1,200 per month.
Risks and considerations (according to the New Zealand AIDS Foundation):
- PrEP offers a high degree of protection but it's not 100% effective. If not taken daily it is less effective: interim findings from PROUD and Ipergay trials showed 86% effectiveness.
- PrEP does not provide protection from any other STIs like syphilis, gonorrhoea, LGV or Hepatitis C. These STIs are on the rise among gay and bisexual men in New Zealand and can increase the possibility of HIV infection.
- Common short-term side effects of Truvada include headaches, weight loss, diarrhoea, nausea, and fatigue.
- Long-term side effects among HIV-negative people on Truvada are currently unknown and research into these side effects is ongoing.
- PrEP should only be used with the support of a sexual health doctor who can provide regular testing for HIV and STIs as well as minimise the risk of drug resistance. It is very important to be tested for HIV before starting PrEP, preferably with a rapid test that has a short window period. If you use PrEP when you already have the HIV virus, or if you use it inconsistently and contract HIV, there is a risk of the virus developing resistance to Emtricitabine, one of the antivirals in Truvada.