Phosphodiesterase type 5 inhibitors
The cyclic nucleotide phosphodiesterases constitute a group of enzymes that destroy the cyclic nucleotides cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Phosphodiesterases exist in different molecular forms and are unevenly distributed throughout the body. One of the forms of phosphodiesterase is termed PDE5, and inhibiting PDE5 increases the amount of cGMP available in the blood supply to the penis, thus increasing blood flow. The PDE5 inhibitors sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis) are prescription drugs which are taken orally.
Extracorporeal shockwave therapy
Extracorporeal shockwave therapy is a relatively new treatment for erectile dysfunction that is non-drug, non-surgical and without adverse side effects. It is the same therapy as used in orthopedics, urology, and cardiology and which at higher energies is used to break up kidney stones, known as lithotripsy. The indication for erectile dysfunction has been approved for use in Europe, most countries in the Middle East and South America as well as in Canada. At this point it has not been approved by the FDA (U.S. Food and Drug Administration).
Pumps
A vacuum erection device helps draw blood into the penis by applying negative pressure. This type of device is sometimes referred to as penis pump and may be used just prior to sexual intercourse. Several types of FDA approved vacuum therapy devices are available with a doctor’s prescription. When pharmacological methods fail, a purpose-designed external vacuum pump can be used to attain erection, with a separate compression ring fitted to the penis to maintain it. These pumps should be distinguished from other penis pumps (supplied without compression rings) which, rather than being used for temporary treatment of impotence, are claimed to increase penis length if used frequently, or vibrate as an aid to masturbation. More drastically, inflatable or rigid penile implants may be fitted surgically.