By: Sylvina Raver, Ph.D.
FDA approves drug for female libido amid controversy and lingering questions
On August 18, the FDA approved the drug flibanserin to treat female sexual dysfunction. Flibanserin, which will be sold under the brand name Addyi, has been billed as “female Viagra” and as a remedy for Female Sexual Interest/Arousal Disorder. With its recent approval, flibanserin becomes the first drug approved to specifically address female sexual problems, compared to the 26 pharmaceuticals approved for this purpose in men. Indeed, highlighting this stark gender inequality in treatment options was instrumental in the drug’s FDA approval. Sprout Pharmaceuticals, Addyi’s manufacturer, joined with non-profit and health care organizations in 2013 to form Even The Score, an advocacy organization that waged a hugely successful lobbing campaign to seek FDA approval of flibanserin by framing its approval as one “women’s sexual health equality.” Critics say that an accusation that the FDA is biased against women, championed by Even The Score, had greater influence on the drug’s approval than did data on the compound’s efficacy and safety. Addyi was found to have an effectiveness rate of between 8 and 13 percent, and led to side effects ranging from dizziness to sudden drops in blood pressure that were exacerbated by alcohol or hormonal contraception. Flibanserin will carry a warning that it can not be taken with alcohol, despite the odd fact that the alcohol safety study submitted to the FDA by Sprout Pharmaceuticals listed 23 of the 25 participants as men. This has led to lingering questions about how women – the intended users of the drug – would react to a flibanserin alcohol interaction, particularly because, unlike Viagra, Addyi is taken daily rather than just before a sexual encounter. The mild effectiveness of flibanserin, combined with concerns about its safety, resulted in two prior rejections of FDA approval prior to the third successful attempt. Addyi comes to market in October 2015. (Cari Romm, The Atlantic; Editorial, Nature)
A universal flu vaccine may soon be a reality
Every fall, millions of people are vaccinated against the flu with vaccines that are developed by scientists who predict which influenza strains are most likely to be problematic that particular year. New shots are required every year because there are thousands of influenza strains that constantly mutate, and one shot cannot protect against them all. Sometimes, the predictions are correct; sometimes, like in 2014, they miss the mark and tens of thousands of US citizens die from influenza. Furthermore, because flu vaccines are currently based on portions of the influenza virus that evolve throughout the flu season, protection is not guaranteed. Two independent groups of scientists have recently reported considerable progress towards a universal flu vaccine by using a novel approach. Both labs targeted hemagglutin, a protein found on the surface of the H1N1 influenza virus, that is composed of a head region that mutates and varies between different flu strains, and a stem region that is constant between different strains and does not mutate.
The two reports – published in Nature Medicine and Science on Wednesday, August 26 – employed different molecular engineering techniques to stabilize the stem portion of hemagglutin when it is isolated from the head region, thus producing a stable structure for the vaccine that is common between different strains. This new method resulted in almost 100% immunity in mice against the lethal H5N1 flu strain, which is distantly related to the H1N1 strain, and partial protection in ferrets and non-human primates. More research is needed to determine whether immunity extends to other strains of the influenza virus, as well as to determine the degree of protection in humans using a vaccine derived with these new approaches. (Hanae Armitage, Science; The Economist)
Public Health and Drug Control Policy
Illicit Version of Painkiller Fentanyl Makes Heroin Deadlier
An extremely potent opioid analgesic called fentanyl, often administered prior to surgical procedures or prescribed for severe cancer-related pain, is increasingly being added to heroin and causing deadly consequences for heroin users across the United States and Canada. Fentanyl is 30-50 times more potent than heroin, and nearly 80-100 times more potent than morphine, and results in a drug combination that is much stronger than what heroin users expect to be administering. The flood of fentanyl-laced heroin is exacerbating the ongoing epidemic of heroin-related overdose deaths, as authorities in some states report a more than 600% increase in fentanyl-related deaths from 2013 to 2014, and see no sign of a slowdown. Drug dealers are increasingly adding fentanyl to heroin in order to restore the potency of the drug that’s been previously diluted by those higher in the distribution chain. Law enforcement officials and policymakers are scrambling to keep pace with the problem. In the past two years, Mexican drug cartels have increased production of a synthetic form of the compound, acetyl fentanyl, that is not yet included in many screens for toxic drugs in the US, and is currently classified as a banned substance in only a few states. Last year the US DEA added acetyl fentanyl to its list of federally banned substances, and in March 2015 the agency issued a warning that fentanyl poses a “threat to health and public safety.” Drug enforcement and public health authorities are attempting to boost public awareness of the dangers of fentanyl-laced heroin, and are alerting local communities when a compound drug batch is detected. (Fred Bever, NPR; Nadia Whitehead, NPR)
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