|
Hopkins Health
New Treatments for Erectile Dysfunction
 |
|
| Urologist Arthur Burnett specializes in erectile dysfunction. |
|
| |
|
For almost a decade, Johns Hopkins urologist Arthur Burnett has been studying the physiology and molecular mechanisms of erectile dysfunction. With the announcement of new therapies available to the public, he shares some of his thoughts about these treatments and his search for a cure.
Question: What’s the most exciting development in the area of erectile dysfunction?
Dr. Burnett: The biggest news in the erectile dysfunction world is the interest in new oral agents, which will probably receive FDA (U.S. Food and Drug Administration) approval imminently. Some are already available internationally. They’re basically in the same class as Viagra–Phosphodiesterase Type 5 Inhibitors that work by inhibiting an enzyme that suppresses the erectile response.
Question: If they’re in the same class as Viagra, how are they different?
Dr. Burnett: One distinction is a longer biological half-life, the time it takes the body to eliminate the drug. Some of these agents are staying in the body much longer than Viagra. One study shows that patients were still getting a pretty good response 24 to 36 hours after taking the drug. So there’s a little more opportunity to be spontaneous, have some romance. You don’t have to be rushed.
Question: If they’re in the body longer, doesn’t that mean any side effects will be stronger, too?
Dr. Burnett: With Viagra, about 16 percent of men experience headaches, 10 percent facial flushing, another 10 percent indigestion, and 4 percent visual disturbances. It’s puzzling, but studies of the new longer-lasting agents show that these side-effects aren’t any more significant.
Question: So, the new oral therapies are better.
Dr. Burnett: Well, they represent an opportunity for patients to have other medications available, to explore them. Whether they’re more effective or not, we’ll have to see. Therapies for erectile dysfunction still have a high dropout rate among men because of the interventions required, repeated situations where you have to do something, even if it’s just taking a pill. Also, you have to remember, these agents are not a cure.
Question: What do you mean?
Dr. Burnett: A cure, defined as restoring normal function, is not what these pills do. They are still just temporary interventions.
Question: So what’s the answer?
Dr. Burnett: The cure may lie in nerve and tissue regeneration. That’s why we’re continuing to study the true patho-physiological mechanism behind erectile dysfunction. We now know that a whole host of neurotransmitters, growth factors, ions, intercellular proteins and hormones are involved in the complex physiology of erection function.
Question: Anything new on the horizon in that area?
Dr. Burnett: Yes. One very exciting finding is that we’ve been able to show in animal models that immunophilin ligands, receptors for immunosuppressant drugs, actually protect damaged pelvic nerves and help to preserve erection. We’re now moving ahead with a trial in which we’ll administer these compounds to patients who undergo nerve-sparing radical prostatectomy. Our hope is that they’ll improve the speed at which men recover their erections, which can take 18 months or longer, following the surgery.
Question: Will that help more men recover their erections, too?
Dr. Burnett: That’s the thinking. Currently, about 40 percent of men experience erectile dysfunction, even with nerve-sparing surgery. These nerves kind of get shocked and need time to recover, and in some men they never recover. If we can figure out ways to push up the time line and preserve erectile function in more men, that would be a tremendous advance.
Question: So things are looking up?
Dr. Burnett: My strong feeling is that while we’re expanding the new oral agents, we’re not at a point where we’ve solved everything. We need to continue scientific investigation in the field to understand the patho-physiologic conditions associated with erectile dysfunction, and to develop therapies that are truly corrective.
|
