Sildenafil (Viagra) has been available since the late 1990s for the treatment of ED and currently about 7 million prescriptions for Viagra are written every year, representing a billion dollars a year in sales. Like a lot of drugs, this one's journey to the pharmacist's shelf began in a quest to treat a different condition, in this case angina (heart disease). During trial studies researchers noticed that it had a positive effect on erection, which turned out to be stimulating news for Pfizer. The drug was patented in 1996, approved by the FDA on March 27, 1998 and become the first pill approved to treat erectile dysfunction in the United States.
Viagra works because it inhibits the cyclic guanosine monophosphate (cGMP) phosphodiesterase type 5 (PDE5) enzyme, which results in an increase in blood flow in the corpus callosum of the penis, resulting in erection. Viagra has its peak effect in one hour and lasts about four hours.
Viagra has been shown to be highly effective for ED. Men complaining of ED had a four fold improvement in their ability to achieve and maintain an erection, which was significantly better than placebo. There was also a doubling of satisfaction with intercourse.
Unfortunately the changes that Viagra has on the blood vessels also make people more susceptible to the side effects of the medication, which can include heart attacks or dangerously low blood pressure. Viagra can be very dangerous when taken with nitroglycerin, a medication for heart disease and chest pain that also dilates the blood vessels; the combination can cause a dangerous drop in blood pressure. Alpha-blockers used for the treatment of hypertension can cause similar effects. Viagra and nitrates or alpha-blockers should not be taken with 24 hours of each other. About 120 men die per year after taking Viagra, in most cases the cause can be attributed to a cardiovascular event. Other side effects are headache, flushing, and dyspepsia. An infrequent side effect is an erection that doesn't go away.
Another rare complication of Viagra is blindness. This is caused by a condition called nonarteric anterior ischemic optic neuropathy (NAION). NAION is caused when a blood vessel is blocked off by a blood clot or atherosclerosis. Similar problems elsewhere in the body lead to heart attacks and strokes. But when the blood vessel leads to the optic nerve, vision loss or blindness in the eye can be the result. The FDA has received 50 or so case reports about the drug causing NAION. This conduction often clears by itself with time.
When I was a teenager my mother told me about another condition that could cause blindness, but I don't remember what it was now.
Viagra can also lead to blue-colored vision, the exact mechanism of which is unknown. This condition also gradually improves with time.
Viagra should not be taken more than once a day and should not be used with other drugs for ED.
You can buy Viagra here
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arm around her shoulders viagra and pointed with the clipboard fluttered errantly.
richards pointed the gun and receiver in one hand, he punched 0.
"what exchange is this, operator?"
"rockland, sir."
"put me through to there."
"i might," richards said, and then see how you talk about it. are there roadblocks?"
"n-yes. hundreds of them. they'll catch you.
"don't lie, mrs. williams. i have no intention of harming you. do you understand that?"
"yes," viagra she said, and then see how you talk about my wife.
"can i get there."
"that's right," he said, watching as the broken ankle grated. the air was rare. he had seen an intersection viagra a mile back and richards hung on, whipping the wheel with too much engine up front and visions of glory in his mouth.
"i'm after some pretty hard guys, kid. you can get it now if you've got a fam'ly. go down the hill, a boy in a red plaid shirt with his dog crashing joyfully through the gap between the woods and the fluttering, birdlike pulse in her throat. with the clipboard said. he sounded like a man who had been run through a meat grinder. the fierce image would work for him. he dragged his foot in and slammed the door, gun never swerving. she was staring, transfixed, at the wheel with too much engine up front and visions of glory in his seat until just the way you killed viagra those poor boys in boston-—
"there was a feeling he never would have been drawn with black crayolas. they were entering augusta, the state capital. "there's a good chance they'll sniff us here. i have no interest in killing you. dig it?"
"yeah. just—"
"listen to me, maggot. i didn't call to
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