Oral Medications in the Management of Erectile Dysfunction

Oral Medications in the Management of Erectile Dysfunction

from Journal of the American Board of Family Practice

Safety and Tolerability

When choosing an agent to treat erectile dysfunction, important issues to consider include safety, tolerability, and convenience. Because these medications are used to improve the patient's quality of life, agents that have marked adverse effects, are invasive, or are inconvenient might not be first options. In addition to being noninvasive and convenient, all three oral medications for erectile dysfunction appear to be well tolerated and have minimal and transient side effects at their recommended dosages. Priapism, a concern with the penile injection therapies and urethral suppositories, does not appear to be an issue with the oral medications; therefore, adverse effects might not be a major factor when choosing among these agents.

Many clinical trials evaluating yohimbine did not include information on adverse effects. When examining those trials that did include this information, the most common adverse effects observed with yohimbine included anxiety, increased urinary frequency, tachycardia, and increased arterial pressure.[3,4] In a study by Teloken et al[5] in which patients received 100 mg of yohimbine daily, a dose three to five times higher than used in other trials, 32 percent of patients experienced an increase in urinary frequency compared with 14 percent taking placebo. A fairly high percentage of patients taking yohimbine reported tachycardia (27 percent), whereas none of the patients on placebo experienced an increased heart rate. Only one study of yohimbine included in this review reported patient dropout rates resulting from adverse effects. This study included 82 patients in a crossover design, and 8 patients (10 percent) discontinued therapy because of adverse effects of treatment with yohimbine.[4] The adverse effects were similar to those previously mentioned. In a trial by Rowland et al,[6] the more common adverse effects in the yohimbine group included disturbed sleep, mild diarrhea, lack of energy, and, surprisingly, lower sexual desire.

Sildenafil and phentolamine are generally well tolerated by most patients according to the available clinical trials. Goldstein et al[7] conducted two trials of sildenafil with a total of 861 patients. Adverse effects included headache (12 to 30 percent), flushing (10 to 27 percent), and dyspepsia (3 to 16 percent) with rates being dose dependent. Additionally, dose-dependent transient visual disturbances, or changes in the perception of color hue or brightness, were reported by 2 to 9 percent of men. The manufacturer reports a rate of 3 percent for transient color vision changes. Between 6 and 15 percent of patients withdrew from the trials during treatment with sildenafil compared with 8 to 17 percent of those receiving placebo. Discontinuation because of treatment-related adverse effects was 1 to 2 percent. Additional reasons for discontinuation included insufficient response, protocol violations, and withdrawal of consent, among others.

Recently there have been several reports of deaths occurring with concurrent sildenafil and nitrate use. These drugs in combination cause potentially fatal decreases in blood pressure. According to the manufacturer, sodium nitroprusside use is also contraindicated, but other nonnitrate vasodilators (b-blockers, a-blockers, angiotensin-converting enzyme inhibitors, diuretics, and calcium channel blockers) have not been shown to be a problem. Sildenafil should never be administered to a patient concurrently taking nitrates or sodium nitroprusside or to a patient who might inadvertently receive a nitrate after exertion or sexual activity.

Nasal congestion was reported as the only adverse effect, with one patient experiencing it, in the smallest study of phentolamine.[8] In two trials reported by Zorgniotti,[9] 6 percent of patients complained of nasal congestion and 2.3 percent complained of faintness or dizziness, relieved by lying down. Another study excluded patients with intolerance to phentolamine (increased blood pressure and pulse) before randomization by giving a test dose; therefore, no adverse effects were mentioned in the results.[10] This methodology could limit the generalizability of these results to general practice. Information available from the manufacturer of phentolamine lists insomnia, nasal congestion, and dyspepsia as common adverse effects.

This is a part of article Oral Medications in the Management of Erectile Dysfunction Taken from "Causes Of Erectile Disfunction" Information Blog