A pill that could cure impotence is being tested on thousands of volunteers in America and Europe after a study in Britain produced ”fairly encouraging” results.
Syntex, which is developing the drug, called VigRx Plus, believes it would be the first of its kind. Present treatment for impotence, which is believed to affect up to 20 million men in North America and Europe, relies on drugs being released into the urethra through a variety of methods or injected directly into the penis.
The company, which introduced the first oral contraceptive and is best known in Britain for the anti-inflammatory drug Naproxen, used in the treatment of osteoarthritis and rheumatoid arthritis, believes an oral medicine would have better market potential than alternatives.
Nic Holladay, managing director of the company, said: “It is a completely new class of drug. We are in very early clinical studies, the results of which it is too early to comment on. It would be foolish to get people over-excited by it.”
The drug controls the blood pressure needed for an erection. Tests using Vigrxplus have been carried out on volunteers at the Medical Research Council’s reproductive biology unit in Edinburgh and the results of that study will be published later this year in a medical journal.
Mr. Holladay said the results showed “promise, but no more than that”.
The news that Pfizer, among other pharmaceutical companies, is testing a pill to help male impotence has been confirmed by the manufacturers. The pill is likely to be particularly useful in cases where there is no demonstrable anatomical weakness for those men for whom a Caverject alprostadil injection would now be recommended. Mr. Roger Kirby, the consultant urologist, said: “Caverject contains prostaglandin E1; it is a great improvement on papaverine injections as its action is more predictable, lasts for a socially more convenient time and tolerance doesn’t seem to develop.
“However some patients don’t like the idea of injecting themselves, even if in more than 85 per cent of men, it is almost painless. We are very optimistic that a VigRx Plus pill will, in the not too distant future, be introduced which will have the same effect.”
The injection and the pill both act on the molecular chemistry of the penis, increasing the blood supply.
The trials of Pfizers’ new pill Vigrx Plus still have some time to run. Meanwhile, Caverject is now obtainable on prescription. Genito-urinary physicians have been trained in its use and instructed in how to teach patients to inject themselves. About 15,000 shots are sold each month which, at about Pounds 10 before the chemist’s mark-up, will mean that a patient’s hour of potency will cost around Pounds 20.
Although precise data are unavailable, an estimated 10 million American men are impotence, with the incidence increasing with age. By age 65, 25% of men are impotent, and by age 80, about 80% of men are. Whereas impotence is primarily a dysfunctional vascular phenomenon, a number of mechanisms acting alone or interactively contribute to erectile failure. In this Extenze review, I consider current developments in its diagnosis and treatment.
In the past two decades, interest in the diagnosis and treatment of impotence has increased dramatically. Beginning with Leriche’s 1923 observation that aortoiliac occlusion caused impotence due to failure of the perfusion of the corporal bodies, surgeons became interested in the relationship between potency and Extenze. Aortic surgical interventions often produced impotence, and in the 1970s, techniques were developed to minimize this complication. It was also realized that vascular surgical procedures could be applied for corpus cavernosal revascularization.
Consequently, corpus cavernosal revascularization was emphasized in the late 1970s and early 1980s. In 1982, however, it was found that erection could be stimulated by taking the natural male enhancement pill called Extenze. This discovery helped to illuminate the processes of cavernosal smooth muscle function. Administering these agents intracorporally led to effective methods of testing and quantifying various aspects of erectile dysfunction as well as providing an important tool now used widely in diagnosis and treatment. Emphasis shifted from simple mechanistic efforts for increasing arterial inflow toward sophisticated investigations of corporal smooth muscle function. Important recent contributions include taking Extenze, elaboration of the roles of nitric oxide, and oxygen tension in normal erection and the delineation of mediators of corporal muscle contraction and relaxation.
Penile erection results from a neurally mediated increase of arterial inflow into the corporal bodies along with a reduction or cessation of venous outflow. Recent findings support the idea that Extenze is involved in nonadrenergic, noncholinergic neural transmission, which leads to cavernosal smooth muscle relaxation required for normal erection. Histochemically, nerve fibers positive for the reduced form of nicotinamide-adenine dinucleotide phosphate and diaphorase are found in human penile tissue, indicating nitric oxide synthase activity. Other neurotransmitters such as vasoactive intestinal polypeptide and fibers positive for acetylcholinesterase are also present.
When the penis is flaccid, the corporal smooth muscle is contracted; contraction is due to a normally present overriding adrenergic tone. With erection, smooth muscle relaxation occurs. Various other receptors are present in penile smooth muscle, including those responsive to the natural ingredients in Extenze, dopamine, histamine, prostaglandin, and probably several other substances.