Viagra treatment
Viagra is the first oral medication designed specifically to treat impotence. Known generically as sildenafil citrate, Viagra works by blocking an enzyme (PDE5), found in the penis, that breaks down a chemical (cyclic GMP), which is produced during sexual stimulation. The longer GMP remains available, the greater the chance of achieving and maintaining an erection. Unlike other drugs commonly used to treat impotence, which are addressed later in this chapter, Viagra does not cause an erection unless the man is sexually stimulated.
Viagra was tested on several thousand men with mild, moderate, or complete erectile dysfunction. These men had a broad range of conditions associated with ED, including high blood pressure, high cholesterol, diabetes, and prostate surgery. Viagra was effective in 50% to 80% of the men who participated in 21 clinical trials. Men with diabetes and those with a history of radical prostate surgery showed less improvement than other groups. No evidence suggests that Viagra enhances the sexual performance of healthy men.
Available by prescription in 25-mg, 50-mg, and 100-mg strengths, Viagra is taken on an as-needed basis, 1 hour before sexual activity, but not more than once a day. Although the cost varies, it generally runs between $8 and $10 a pill. The most common side effects associated with Viagra are headache, flushing, indigestion, stuffy nose, and diarrhea. In addition, about 3% of patients participating in the clinical trials reported temporary changes in their vision, including sensitivity to light and seeing a bluish tinge. Men who use nitroglycerin, either in a patch or as a pill under the tongue, or other heart medicines containing nitrates should not take Viagra because combining the two may lower blood pressure to life-threatening levels. No studies have been conducted to test the safety and effectiveness of Viagra when combined with other treatments for impotence or other prescription medications. Therefore, you should tell your doctor about all the medications you are taking, including over-the-counter drugs.