Friday, January 4, 2013

Potential Substitutes for Viagra

Surfing on Internet I have found a 4-year old article about wonderful properties of an ordinary watermelon. You can read this article on this page - http://goo.gl/hGQhg .  In a nutshell this article tells that a watermelon contains a specific substance called citrulline whose effect is similar to Viagra’s action. Remembering about “herbal” Viagra and about many other medicines to improve men’s erection I have thought that there must be much cheaper remedies to heal impotence (or to raise existing sexual power)  than notorious “blue diamond”.

Why do I think so? Because from the medical point of view sildenafil citrate (the agent of Viagra, Revatio and of other brand name medicines) is just a relaxant of smooth muscle. Smooth muscle is responsible for contractility of blood vessels, including veins and corpora cavernosa in penis. When smooth muscle in veins has been relaxed then the veins are full with blood and increase in volume. Man’s penis is not a muscular organ as many people think, but a venous sponge which swells when veins in it are full of blood and which sinks in when blood leaves its veins. Additional volume of blood to fill dilated veins in penis appears due to more intensive work of heart that has been stimulated by sexual arousal of nervous system. The more veins and corpora cavernosa have been dilated the more blood they can take and since the more voluminous penis can a man get.

Penis veins  can be widen by  the same  medicines  which dilate veins in other part of man’s body, for example by nitroglycerin, isosorbide mononitrate (some trade names are Imdur, Monosorb, Chemydur),isosorbide dinitrate (most popular trade name is Dilatrate), pentaerithrityl tetranitrate (one of brand medicines is Lentonitrat) etc. Why then doctors do not prescribe such medicines to persons who suffer erectile dysfunction?

     In the first place because these medicines (nitroglycerin, isosorbide mononitrate etc.) were not clinically tested to cure erectile dysfunction and nobody knows the necessary dosage and possible side effects.

     In the second place because these medicines have been used for a long time to treat heart diseases but cardiologists have nothing to do with sexual problems. That is defect of modern professional specialization.

     In the third place because patents for these medicines are void and nobody will invest in researches how to treat sexual disorders with these remedies because such an investor hardly can return invested capitals without patent protection.

     In the fourth place because sildenafil is relatively selective drug and touches with its effect initially small pelvis organs including penis and pulmonary vessels. Much later when its concentration in blood falls sildenafil exerts a general impact on the human body. This general impact reveals itselflf in a decrease of mean arterial pressure. Trials with healthy volunteers showed that such decrease is 8.4 mmHg (millimeters of mercury column) when dosage was 100 mg. Many side effects of Viagra have been caused exactly by its property to reduce blood pressure in whole body. Among such side effects are for example headache, flushing, hypotension etc.

So cheap, old and reliable medicines are not used to cure men’s impotence, but we have been surrounded by ads urging us to buy an expensive Pfizer’s product.