A study presented at October’s HIV Research for Prevention conference (HIVR4P) in Madrid shows that transgender women who are taking feminising hormones and also taking pre-exposure prophylaxis (PrEP) have levels of the PrEP drugs tenofovir and emtricitabine in their blood that are about 25% lower than those in cisgender men, and levels in rectal tissue cells about 40% lower. Tenofovir levels in rectal tissue were 44% lower.
However, the study also confirmed that the interaction between hormones and PrEP did not appear to go the other way; blood levels of estradiol, the one hormone all of the transgender women took in one form or another, do not appear to be affected by PrEP.
Daily use of co-formulated tenofovir and emtricitabine for HIV pre-exposure prophylaxis (PrEP) by populations at high risk of HIV infection is now recommended in guidelines from the United States, Europe and Australia and globally through the 2015 WHO guidelines.
These 2017 Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine‘s (ASHM) PrEP Guidelines are an updated adaptation of the 2014 US Centers for Disease Control‘s PrEP guidelines and are designed to:
• Support the prescription of PrEP using forms of coformulated tenofovir and emtricitabine that have been registered in Australia by the Therapeutic Goods Administration and other bioequivalent generic drugs that are available in Australia through self-importation, private prescription or Australian PrEP clinical trials
• Assist clinicians in the evaluation of patients who are seeking PrEP
• Assist clinicians in commencing and monitoring patients on PrEP including PrEP dosing schedules, management of side-effects and toxicity, use of PrEP in pregnancy and in chronic hepatitis B infection and how to cease PrEP
Daily PrEP with co-formulated tenofovir and emtricitabine, used continuously or for shorter periods of time, is recommended in these guidelines as a key HIV-prevention option for men who have sex with men (MSM), transgender men and women, heterosexual men and women, and people who inject drugs (PWID) at substantial risk of HIV acquisition.
Two statisticians involved in the PROUD and iPrEx trials of pre-exposure prophylaxis (PrEP) warn that future trials to test new PrEP drugs and formulations may be extremely difficult to design.
David Dunn of the UK Medical Research Council and David Glidden of the University of California, San Francisco say that statisticians will need to choose and analyse their trial population very carefully if they wish to be able to demonstrate meaningful results.
In one of the most tightly controlled trials ever conducted of drugs used to treat sexually transmitted infections, researchers at the University of Alabama at Birmingham have confirmed that azithromycin remains effective in the treatment of urogenital chlamydia.
In a study published Dec. 24 in the New England Journal of Medicine, the research team compared two of the most commonly used medications for urogenital chlamydia.
The results from the Ipergay study of intermittent pre-exposure prophylaxis (PrEP) were published in the New England Journal of Medicine (NEJM) on 1 December, World AIDS Day. The journal-published results are little changed from those presented at the CROI conference last February by principal investigator Jean-Michel Molina, but the researchers make a number of additional comments and are notably cautious about not over-interpreting a study that only had 400 participants – very small for a prevention study – and an average of nine months’ follow-up.
It is the first, and so far only. randomised study to show that PrEP can be just as effective if it is given as an intermittent regimen that users only take when anticipating sex, rather than daily.