Erectile dysfunction (ED) is a common condition that occurs in more than half of men between the ages of 40 and 70 years, with complete ED occurring in more than 10% in this age group.

Erectile dysfunction is defined as the consistent (usually for 6 months' duration) inability to attain or maintain penile erection satisfactory for sexual intercourse (vaginal penetration).

Penile erection is a transient event, unlike other physiological processes which continue unabated throughout life, such as heart rate, breathing, digestion, etc.

Penile erection involves a number of different neural transmitter systems, both in the central and peripheral nervous system, as well as peripherally in the penis itself.

The management of ED has dramatically changed in the past 5 years and especially since the approval and availability of the first effective oral medication, Viagra (sildenafil citrate).

Because of the recent publicity with sildenafil, there has been increasing awareness amongst the population at large as to ED, its causes, its workup, and its treatment.

What factors cause ED?:

• Cardiovasular disease
  
• Diabetes
  
• Depression
  
• Patient attitudes toward treatment
  
• Co-administered medications (anti-hypertensive agents, serotonin reuptake inhibitors)
  
• Spinal cord injury patients
  
• Transplants
  
• Prostate disease
  
• Renal failure
  
• Age
  
• Obesity

General update
A recent global sexual health survey (Dale B. Glasser, Ph.D., New York) found that the majority of adults worldwide remain sexually active into their later years. With an increasingly aging population, these statistics are important. Sexual health has a considerable impact on a person's overall feeling of well-being. More than 4 of 5 men and nearly 2 of 3 women in this survey said that sex was extremely, very or moderately important in their overall lives.

Effect of smoking on the reversal of ED
Smoking exerts an atherogenic effect on penile blood flow causing a vascular impairment to erectile function.

After patients stop smoking, the reversibility of ED is dependant on whether the disease process is so advanced that reversibility is unlikely. Elist (Urology, 1984) showed that 40% of patients recovered erectile function after abstaining from cigarettes for 6 weeks. Also, Mannino found that the prevalence of ED was significantly lower in former smokers than in active smokers.