Sildenafil (Viagra)

Sildenafil (Viagra) was approved by the Food and Drug Administration (FDA) in 1998, becoming the first oral medication for erectile dysfunction (ED Treatments Learn More) on the market. Since then, doctors have written millions of prescriptions for the blue, diamond-shaped tablets. Drugs for treating ED can be taken orally, injected directly into the penis, or inserted into the urethra at the tip of the penis. In August 2003, the FDA gave approval to a second oral medicine, vardenafil hydrochloride (Levitra). Following Levitra, Cialis (tadalafil) was the approved in November 2003 by the FDA.

Taken an hour before sexual activity, Viagra and Levitra work by enhancing the effects of nitric oxide, a chemical that relaxes smooth muscles in the penile arteries (and arteries in general) during sexual stimulation allowing an increased blood flow.

While oral medicines improve the response to sexual stimulation, they do not trigger an automatic erection as injections do. The recommended dose for Viagra is 50 mg, a physician may adjust this dose to 100 mg or 25 mg, depending on the patient’s condition severity. The recommended dose for Levitra is 10 mg; a physician may adjust this dose to 20 mg if 10 mg is insufficient. Lower doses of 5 mg and 2.5 mg are available for patients who take other medicines or have conditions that may decrease the body’s ability to use Levitra. Cialis is currently available as 2.5 mg, 5 mg, 10 mg, and 20 mg tablets for the treatment of ED. The major advantage of Cialis in comparison to Viagra and Levitra is its 17.5 hour half-life time which makes the drug to be effective for up to 36 hours. Hence, the higher doses of Cialis (10 mg and up) should not be used more than one tablet every other day. In October 2011, the U.S. FDA approved daily Cialis 5 mg tablets for the treatment of signs and symptoms associated with benign prostatic hyperplasia (BPH) and also erectile dysfunction (Penile Prosthesis Learn More), if both conditions coexist.

Neither Viagra nor Levitra or Cialis should be used more than once a day. Men who take nitrate-based drugs such as nitroglycerin for heart problems should not use either drug (ED & Drugs Learn More), as the combination can cause a sudden drop in blood pressure. Levitra should not be taken with any of the drugs called alpha-blockers, which are used to treat prostate enlargement or high blood pressure.

Oral Medicines Being Tested For Safety & Effectiveness.

Oral testosterone (Hormonal Imbalance Learn More) can reduce ED in some men with low levels of natural testosterone, but it is often ineffective and may cause liver damage. Patients also have claimed other oral drugs–including yohimbine hydrochloride, dopamine and serotonin agonists, and trazodone– to be effective. The results of scientific studies to substantiate these claims have been inconsistent. Improvements observed by the use of the drugs may be examples of the placebo effect; a change that results simply from the patient’s believing that an improvement will occur.

Many men achieve stronger erections (Harder Erection Learn More) by injecting drugs into the penis, causing it to become engorged with blood. Drugs such as papaverine hydrochloride, phentolamine, and alprostadil (marketed as Caverject) widen blood vessels. These drugs may create unwanted side effects such as a persistent erection (known as priapism) and/ or scarring. Nitroglycerin, a muscle relaxant, can sometimes enhance erection when rubbed on the penis.

A system for inserting a pellet of alprostadil into the urethra is marketed as Muse. The system uses a prefilled applicator to deliver the pellet about an inch deep into the urethra. An erection will begin within 8 to 10 minutes and may last 30 to 60 minutes. The most common side effects are aching in the penis, testicles, and area between the penis and rectum, warmth or burning sensation in the urethra, redness from increased blood flow to the penis, and minor urethral bleeding or spotting.

Research on drugs for treating ED is expanding rapidly. Patients should ask their doctor about the latest advances.