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Nonsurgical Treatment of Erectile Dysfunction (cont.)


Medications can be used to treat erectile dysfunction, some of which are discussed below. For a more complete discussion, see Understanding Erectile Dysfunction Medications.

Viagra, Levitra, and Cialis

Since the introduction of Viagra (sildenafil citrate) in March 1998, no other therapy for erectile dysfunction has achieved such wide public recognition.

Viagra is the first oral medicine (a pill you take by mouth) available that has been proven to improve erections in men who have difficulty achieving or maintaining erections sufficient for sexual intercourse due to erectile dysfunction. Viagra does not improve erections in healthy men. It is not an aphrodisiac and will not increase sexual desire.

Since its introduction, the Food and Drug Administration (FDA) has approved two additional drugs in the same class as Viagra:

  • Levitra (vardenafil) and Cialis (tadalafil) have essentially the same activity as Viagra.

  • Cialis has a longer duration of increased sensitivity to develop an erection (up to 24-36 hours) compared with Viagra and Levitra (up to 4-16 hours).

Viagra, Levitra, and Cialis work by blocking an enzyme found mainly in the penis that breaks down a chemical created during stimulation that increases blood flow in the erectile bodies of the penis, which then produces erections. Viagra, Levitra, and Cialis allow this chemical of arousal to survive longer and greatly improve erectile function. Viagra, Levitra, and Cialis will not have any effect without sexual stimulation.

  • Viagra, Levitra, and Cialis work successfully in about 65-70% of all men with erectile dysfunction.

  • Of those men with diabetes or with spinal cord injury, between 50-60% reported being successfully treated with these medications.

  • In men who became impotent after radical prostate cancer surgery, 43% reported improved erections with Viagra, particularly if they had the "nerve-sparing" type of prostate surgery. These medications are most effective if there is some erectile function; if there is no erectile function, these medications are not usually beneficial.

Viagra is available in 3 doses: 25 mg, 50 mg, and 100 mg. Viagra works best if taken on an empty stomach about 30-45 minutes before sexual activity. Optimal results may not be realized until the medication has been tried 6-8 times. Viagra may be used cautiously with alpha-blocker medications as long as sufficient time has passed between their dosing.

Levitra is available in 2 doses: 10 mg and 20 mg. It is not necessary to take it on an empty stomach. Currently, Levitra cannot be used with any alpha-blocker medication because of potentially dangerous drops in blood pressure. Many people who fail Viagra therapy have found Levitra to be effective.

Cialis is available in 2 doses: 10 mg and 20 mg. Cialis can work in 30 minutes, but peak results usually take longer. Cialis has the advantage of a much longer period (24-36 hours) during which sexual ability is increased. Cialis may be used with the alpha-blocker medication Flomax but not with other alpha-blocker medications.

Side effects of Viagra, Levitra, and Cialis can occur but are generally mild. They include:

  • Headache

  • Hypotension (a drop in blood pressure)

  • Transient dizziness

  • Facial flushing

  • Indigestion

  • Nasal congestion

  • Lower back pain (unique to Cialis)

  • Visual disturbance (eg, blurred vision, increased light sensitivity, persistence of a bluish tinge, temporary loss of the ability to distinguish between blue and green)

Your physician will determine which of these medications is most appropriate for you and the optimal dosage. Never give any of these medications to anyone else as they can cause serious problems due to drug interactions if not monitored by a physician.

Medications, such as ketoconazole (an antifungal medication known as Nizoral), erythromycin (an antibiotic), and cimetidine (a drug to reduce stomach acid known as Tagamet), can interfere with the chemical processing of medications like Viagra by the liver.

Alpha-blocker type medications (eg, Hytrin, Cardura, Uroxatral, Flomax) may have potentially dangerous interactions with Viagra, Levitra, and Cialis. If you are taking any of these medications, check with your physician or pharmacist about potential drug interactions.

Certain street drugs (eg, ecstasy) can also cause serious problems if taken with Viagra, Levitra, or Cialis.

Viagra, Levitra, and Cialis should absolutely not to be taken by:

  • Men with heart conditions who are taking nitrates, such as nitroglycerine (Combining Viagra, Levitra, or Cialis with nitrate-based medications can cause a severe and dramatic drop in blood pressure with potentially very dangerous consequences.)

  • Men with serious heart disease or exertional angina (chest pain)

  • Men who are taking multiple drugs for high blood pressure


Yohimbine, an herbal product, comes from the bark of a West African tree. Its use in treating erectile dysfunction is questionable, and, in studies, yohimbine is only slightly better than placebo (no drug at all).

Nonetheless, yohimbine is considered safe with few known side effects. The usual daily dose is a 5.4-mg tablet taken 3 times a day.

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