A few days ago, an article appeared on AidsMeds.com about the drug Tenofovir being associated with an increased risk of irreversible kidney disease, which does not reverse even when the drug is no longer taken. Tenofovir is one of the main ingredients in a vaginal gel developed to reduce the transmission of HIV, although a recent trial was stopped early because the gel was found to be ineffective. Another trial of Tenofovir taken orally as pre-exposure prophylaxis was also stopped early as it was clear it would not be possible to demonstrate a difference in effect between the drug and a placebo.
Despite these findings, Poz.com reports that the US Food and Drug Administration (FDA) has accepted an application from the makers of Tenofovir, Gilead Sciences, to give a priority review of the use of the drug, in combination with emtricitabine, to be marketed as Truvada. Despite some less favorable findings about Tenofovir, the more favorable findings led to immediate calls for application for use as PrEP to be fast-tracked.
In addition to the above worries about Tenofovir, widespread use of PrEP is also likely to give rise to drops in use of condoms. This possibility is denied vigorously by defenders of PrEP, and some data has been produced to support that defence. But like male circumcision and the hormonal contraceptive Depo Provera, people tend not to think about dual protection against both HIV and unplanned pregnancy.
Interestingly, while injectable versions of Depo Provera and similar methods are said to be 'female controlled' relative to the oral version, this objection doesn't appear to be used or alluded to by proponents of PrEP or vaginal gel.
A paper has been published discussing these diverging trial results and the authors pay particular attention to adherence to the drug regime, which needs to be very high. The authors mention identifying "optimal populations for PrEP"; but they may find that these populations are least likely to need the drug. It's all beginning to sound like a product in search of a market; but where would Big Pharma be if it never took that approach?
Sunday, February 19, 2012
Saturday, February 4, 2012
Apologies for Lack of Posting
It's been some time since I have been able to write a post for this blog but I will get back to it as soon as possible. I also write about the lunacy of prohibitively expensive and purely technical approaches to what are public health and development issues on my HIV in Kenya blog and also on the Don't Get Stuck With HIV blog and website.
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