sexhealth

My husband has some Erectile Dysfunction problems but also some emotional ones related to sex. His doctor found he has low testostrone and has been treated for that for a couple of months so far. He has also been given Viagra and some other drugs to try at the time of sex. But now he is so scared of failure that he won't even try. I have tried to start something - once with no warning, once preplanned - this weekend and he turned me down. What can I do to help him? He cannot get past the block until he tries.

Sildenafil (compound UK-92,480) was synthesized by a group of pharmaceutical chemists working at Pfizer's Sandwich, Kent research facility. It was initially studied for use in hypertension (high blood pressure) and angina pectoris (a form of ischaemic cardiovascular disease). Phase I clinical trials under the direction of Ian Osterloh suggested that the drug had little effect on angina, but that it could induce marked penile erections. Pfizer therefore decided to market it for erectile dysfunction, rather than for angina. The drug was patented in 1996, approved for use in erectile dysfunction by the Food and Drug Administration on March 27, 1998, becoming the first pill approved to treat erectile dysfunction in the United States, and offered for sale in the United States later that year. It soon became a great success: annual sales of Viagra in the period 1999–2001 exceeded $1 billion.

The British press portrayed Peter Dunn and Albert Wood as the inventors of the drug, a claim which Pfizer disputes. Their names are on the manufacturing patent application drug, but Pfizer claims this is only for convenience.

Even though sildenafil is only available by prescription from a doctor, it was advertised directly to consumers on US TV (famously being endorsed by former United States Senator Bob Dole and football star Pelé). Numerous sites on the Internet offer Viagra for sale after an "online consultation", a mere web questionnaire. The "Viagra" name has become so well known that many fake aphrodisiacs now call themselves "herbal Viagra" or are presented as blue tablets imitating the shape and colour of Pfizer's product. Viagra is also informally known as "Vitamin V", "the Blue Pill", as well as various other nicknames.

In February 2007, it was announced that Boots the Chemist would trial over the counter sales of Viagra in stores in Manchester, England. Men aged between 30 and 65 would be eligible to buy four tablets after a consultation with a pharmacist.

Pfizer's worldwide patents on sildenafil citrate will expire in 2011–2013. The UK patent held by Pfizer on the use of PDE5 inhibitors (see below) as treatment of impotence was invalidated in 2000 because of obviousness; this decision was upheld on appeal in 2002.

http://en.wikipedia.org/wiki/Viagra

"You are not alone if you are suffering from ED. More than 50% of men over the age of 40 suffer from some form of Erectile Dysfunction (ED). ED affects approximately 30 million men in the United States."

Erectile dysfunction is a cause of misery, relationship difficulties, and significantly reduced quality of life for many men and their partners.

The erection of the penis involves release of nitric oxide (NO), a chemical that is normally released in response to sexual stimulation, in the corpus cavernosum of the penis.

• Nitric oxide then activates an enzyme called guanylate cyclase, which, in turn, results in increased levels of cyclic guanosine monophosphate (cGMP).
• This produces smooth-muscle relaxation in the corpus cavernosum and allows the inflow of blood. [There are three types of muscles: smooth, cardiac, and striated. Smooth muscles are those that are involuntary in action and are found principally in internal organs.]
• Viagra (sildenafil citrate) has no direct relaxant effect on the human corpus cavernosum.
• Instead, sildenafil enhances the effect of nitric oxide (NO) by inhibiting phosphodiesterase type 5 (PDE5).
• PDE5 is responsible for degradation of cGMP in the corpus cavernosum, which causes the penis to become flaccid, or relaxed.
• When sexual stimulation causes local release of NO, sildenafil inhibits PDE5, which, in turn, causes increased levels of cGMP in the corpus cavernosum. This results in continued smooth-muscle relaxation, allows for inflow of blood to the corpus cavernosum, and erection of the penis.
• Sildenafil at has no effect in the absence of sexual stimulation.

http://healthcare.utah.edu/healthinfo/adult/men/viagra.htm