More clinical trials in Africa
Posted by Henry Bauer on 2009/07/31
“AIDS prevention trial in Zimbabwe targets women
Wed Jul 22, 2009 12:25pm EDT
About 5,000 sexually active women are expected to enrol at sites in Zimbabwe, South Africa, Uganda, Zambia and possibly Malawi as part of the study, conducted by the U.S-funded Microbicide Trials Network.
The study will determine whether some of the antiretroviral (ARV) medicines used to treat HIV can also be used to prevent the disease when given as a vaginal microbicide gel or as an oral tablet taken once daily.
In addition, the study, which will specifically test the ARV tablets tenofovir and Truvada, seeks to find out which of the two approaches women would prefer. Tenofovir was also the active ingredient in the vaginal gel.
‘We think its very unique because nobody has really tested the difference between an oral route of prevention compared to a vaginal route of prevention,’ Dr Mike Chirenje, protocol co-chair for the entire study, told Reuters on the sidelines of an AIDS conference. ‘Its not so much which was best, in so much as what would women prefer (to take),’ he said of a study expected to last three and a half years before first results in 2012.
Recent studies have shown that microbicides can protect women — who represent nearly 60 percent of adults living with HIV in the world’s worst affected sub-Saharan Africa region — from catching the virus.”
Those “recent studies” were not cited, however. For a summary of the failures of microbicide research, see “The Research Trough — where lack of progress brings more grants”, 10 September 2008. Less than a year ago, it had been noted that “two decades of studying microbicides that would block HIV and other sexually transmitted diseases” had led to “several promising candidates that interfere with the process that allows HIV to replicate” — which is far from preventing “infection” in the first place, which is what microbicides or vaccines are intended to do.
What to say about a trial that will feed antiretroviral drugs for 3½ years to 5000 women who are not even “infected”?
For tenofovir (TDF) it is known, for example, that “Renal impairment, manifested by increases in serum creatinine, glycosuria, hypophosphatemia, and acute tubular necrosis, has been reported . . . . In patients who have some degree of pre-existing renal insufficiency . . . tenofovir dosage adjustment is required. However, because no safety and efficacy data that use the dosage adjustment guidelines for renal dysfunction are available, the use of alternative NRTIs (especially abacavir) may be preferred over dose-adjusted tenofovir in this setting” [p. 33, NIH Treatment Guidelines, 3 November 2008]. In addition to renal damage, “adverse events” of TDF include “asthenia [loss of energy], headache, diarrhea, vomiting, flatulence, Fanconi syndrome [a specific form of renal dysfunction], osteopenia [bone loss not yet as severe as osteoporosis]”. Truvada combines TDF with FTC (emtricitabine) which adds the risk of skin discoloration (p. 131).
The popular paraphrase of the Hippocratic Oath, “First, do no harm”, would seem difficult to reconcile with feeding dangerous drugs to healthy human beings when the only conceivable purpose is to find a means of protection that might be an alternative to the entirely non-dangerous use of condoms — leaving aside the fact that there’s not even a sexually transmitted “HIV” to be protected against.
This entry was posted on 2009/07/31 at 10:36 am and is filed under antiretroviral drugs, clinical trials, HIV transmission, sexual transmission, vaccines. Tagged: antiretroviral drugs as microbicide, “side” effects of antiretroviral drugs, Emtricitabine, HIV microbicide trial, Mike Chirenje, prophylactic antiretroviral drugs, Tenofovir, toxicity of antiretroviral drugs, Truvada. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.