Viagra was the first prescription drug in its class approved by the FDA for erectile dysfunction. Known generically as sildenafil citrate, it is available as a 25-mg, 50-mg or 100-mg oral tablet. Viagra was the 38th highest-selling drug, in terms of retail dollars, in 2008, reports Drugs.com.
Function
Usually, when a men is sexually aroused, the blood flow to the penis is increased, making the penis swell and become erect. Various health conditions and medications can impede this process, creating a condition known as erectile dysfunction. Viagra and similar drugs work by allowing the penis to fill with blood during sexual excitement, causing an erection.
Limitations
Some men cannot use Viagra, including men who take nitrates. According to the drug manufacturer, taking this medicine with a nitrate can cause a dangerous drop in blood pressure.
Side Effects
In addition to its intended effect, sidenafil commonly causes flushing, heartburn and headache. Rarely, a man will experience an erection that lasts for more than four hours. If this happens, immediate medical care must be sought.
Considerations
This medication should be taken from 30 minutes to four hours prior to intended sexual activity. It takes longer to take effect if it is taken at the time of a high-fat meal. Grapefruit juice should not be taken with Viagra.
Common Misconceptions
Contrary to common misconception, Viagra will not cause a man to have an erection if he is not sexually excited. It will also not cause him to become sexually aroused.
References
- "2010 Lippincott's Nursing Drug Guide"; Amy M. Karch, R.N., M.S.; 2010
- Pfizer, Inc.: Viagra Prescribing Information
- Drugs.com: Top 200 Drugs for 2008 by Sales
