ABSTRACT
Erectile dysfunction (ER) is the inability to attain or maintain a sufcient penile erection for a satisfactory sexual intercourse [1]. ER affects nearly 2% men under the age of 40 and 50%–86% of men aged 45 or older [2,3]. The disease affects about 18.4% of Americans aged 18 years or older [4] and 152 million men worldwide [5]. The term ER has also replaced the term “impotence” that is not often used any more.
