If unsuccessful, does not interfere with other treatments With the introduction of effective pharmacologic therapies for erectile dysfunction, more men are seeking treatment. The underlying cause of erectile dysfunction is usually a chronic medical illness or a side effect of certain drugs. Less commonly, the problem is psychogenic. Even after optimal treatment of common medical disorders such as diabetes mellitus and hypertension, erectile dysfunction may persist. Pharmacologic treatments, such as the intracavernosal or transurethral administration of alprostadil or the use of the new oral medication sildenafil, may offer patients substantial benefit. Before any of these drugs are prescribed, consideration should be given to existing medical illnesses and medications, partner satisfaction, comfort with the method of administration and the side effect profile. (Am Fam Physician 1999;60:1159-72.) Failure to achieve an erection less than 20% of the time is not unusual and treatment is rarely needed. Failure to achieve an erection more than 50% of the time, however, generally indicates there is a problem requiring treatment. buy Viagra 50mg here buy viagra without prescription online Because of its unique locally acting mechanism of potentiating the physiologic response to sexual arousal, sildenafil is effective in men with erectile dysfunction of organic, psychogenic or combined causes. The use of sildenafil in women is under study but has not yet been approved.