Nanoparticles encapsulating nitric oxide or prescription drugs show promise for the topical treatment of erectile dysfunction (ED), according to a new study from the Albert Einstein College of Medicine.
The new system, tested successfully on a small number of animals, could prevent the side-effects sometimes associated with oral ED medications. That could mean safer and more effective ED therapy for millions of men with heart disease and other health problems affecting erectile function.
While millions of men worldwide have benefited from oral ED medications such as Viagra and Levitra, they can cause side effects that can be serious. These side effects include headache, facial flushing, nasal congestion, upset stomach, abnormal vision as well as isolated reports of hearing and vision loss. And men who've recently suffered a heart attack or stroke or have severe heart disease should use these drugs with caution or not at all. The researchers say that 30 to 50 percent of men with ED do not respond to orally administered ED meds.
The new drug-delivery system, reported in the Journal of Sexual Medicine, consists of nanoparticles - each smaller than a grain of pollen - that can carry tiny payloads of drugs and release them in a controlled and sustained manner.
Until now, topical formulations of ED drugs were ineffective. This study was done to evaluate whether the nanoparticles, which have been shown to penetrate the skin, might allow the targeted delivery of compounds that treat ED.
An effective topical therapy could be especially significant for those ED patients - particularly men with diabetes - who have reduced levels of nitric oxide, the signaling molecule that dilates blood vessels responsible for erectile activity. These men, who often aren't helped by oral drugs, may benefit from direct application.
The nanoparticles were tested on a total of 18 rats bred to have age-related ED. "Most of the animals, nearly 90 percent, showed a response to treatment with the nanoparticles," says study co-author Joel M. Friedman. "The response time to the nanoparticles was very short, just a few minutes, which is basically what people want in an ED medication." Importantly, the researchers found no indication of systemic side effects. Clinical studies on humans could begin in a few years if animal studies continue to show that the nanoparticle delivery system is safe and effective.
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Source: Albert Einstein College of Medicine