Currently there is only one oral medication approved by the FDA to treat erectile dysfunction. Sildenafil (Viagra) was approved by the FDA in 1998 and represents a milestone in the field of erectile dysfunction. Viagra works by increasing blood flow to the penis, as well as causing penile muscles to relax. It does not initiate an erection however, rather it helps to store penile blood flow in response to sexual stimulation by counteracting the chemical Phosphodiesterase V that takes away an erection.
This is very important to understand because it means that for Viagra to be effective one must be able to initiate a partial erection in response to sexual stimulation. In the absence of this partial erection or without sexual, tactile stimulation, Viagra will be ineffective. A high-fat meal will delay absorption and if the stomach is empty Viagra will be fully absorbed in a little less than an hour. If an erection occurs before it is fully absorbed, the chemical that takes away erections will not be fully counteracted and will begin to take away the erection. One must be patient. Fatigue, anxiety, a heavy meal, and large amount of alcohol intake will diminish the erectile response to Viagra. Viagra will remain in the body four to eight hours and the higher the dose (100 milligrams) the broader the window of sexual opportunity becomes. Most men (80 percent) require the 100-milligram dose. Finally, Viagra is effective regardless of the cause of the erectile dysfunction, including hypertension, coronary disease, prostate cancer, diabetes, depression, or age of the patient.
Side effects of Viagra include headaches, redness of the face, nasal stuffiness, and heartburn. Three percent of men may experience visual disturbance in the form of an increased sensitivity to light or seeing a bluish tint to everything. All side effects are very mild, well-tolerated, transient, and actually very few patients discontinue use because of them.
Viagra is contraindicated for men who take medications that contain nitrates of any form or schedule. Viagra should never be taken by a patient who is on nitrates.
The FDA could possibly approve apomorphine SL (Uprima) as early as July 1, 2000. This drug works on the brain centers that control erections and helps men obtain and/or maintain an erection. Although effective in clinical trials, the medication is currently not available for clinical use. Side effects are very infrequent and mild and include nausea and dizziness to the point of passing out (syncope). With correct use these side effects may be prevented.
Yohimbine is a popular oral medication, but its effectiveness has been disappointing. In men who suffer from physical ED, it is as effective as a sugar pill (placebo).
Phentolamine (Vasomax) was found to cause liver abnormalities in study animals, prompting the company (Nonagon) to withdraw the new drug application from the FDA. This medication most likely will never be available clinically.
The antidepressant drug Trazodone, taken one hour before sexual activity, has been found to prolong erections in men who are able to obtain, but not maintain an erection during intercourse. Trazodone, however, is much less effective than Viagra.
Finally, several Phosphodiesterase Inhibitors (Viagra-like) are currently being developed (ICOS, Bayer). It is unlikely, however, that efficacy or profile of side effects will be much different than Viagra.
Internal Penile Pump™
The Internal Penile Pump (IPP) is a soft-fluid-filled (saline) device that can expand and contract without losing elasticity. It consists of three small components: very thin tubes, pump, and reservoir. The reservoir contains the saline, which is transferred by the pump into the penis, causing the penis to expand and become rigid. There are more than 250,000 men who have the Internal Penile Pump.