What Medications Treat Erectile Dysfunction?
Medications can be used to treat impotence, some of which are discussed below. For a more complete discussion, see Erectile Dysfunction Medications. Currently, oral medical therapy is considered the first line therapy in men with erectile dysfunction who have no contraindications to its use.
Phosphodiesterase type V inhibitors (PDE-5 inhibitors) are the most commonly used therapy for erectile dysfunction. These medications work by preventing the breakdown of chemicals that stimulate increased blood flow into the penis. Several different PDE-5 inhibitors are available, which differ slightly in how to use them and their side effects. They appear to be equally effective in the treatment of erectile dysfunction in general, but some individuals may respond to one of these medications more effectively than another.
Although these medications are the most commonly used for erectile dysfunction treatment, there are some individuals in whom these medications should not be used:
PDE-5 inhibitors are contraindicated in men taking any form of nitrates, such as nitroglycerin and in men taking guanylate cyclase inhibitors.
These medications should not be used in individuals with a condition called retinitis pigmentosa.
Caution is recommended regarding the use of PDE-5 inhibitors and alpha-blockers (for example, Hytrin, Cardura, Uroxatral, Flomax, Rapaflo), medications commonly used to treat benign prostate enlargement (BPH). The combination of these medications can cause lowering of the blood pressure. Stable use of one therapy should occur prior to the addition of the other therapy, which should start at a low dose.
Currently, there are four different PDE-5 inhibitors available, sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis), and avanafil (Stendra). All of these medications require sexual stimulation to achieve an erection. None of these medications will improve sexual desire, nor will they improve normal erections.
- Levitra, Cialis, and Stendra 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 four to 16 hours) and is the only medication that can be taken daily. Stendra can work as rapidly as 15-30 minutes and can be taken with alcohol.
- Viagra, Levitra, Stendra, and Cialis work successfully in a majority of all men with erectile dysfunction.
- Of those men with diabetes or with spinal cord injury, a majority reported being successfully treated with these medications.
- In men who became impotent after radical prostate cancer surgery, almost half reported improved erections with sildenafil, 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 three strengths: 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 six to eight times. Viagra may be used cautiously with alpha-blocker medications as long as sufficient time has passed between their dosing.
Levitra is available in two strengths: 10 mg and 20 mg. It is not necessary to take it on an empty stomach. Levitra should be started at low dose in men taking certain medications called CYP3A4 inhibitors (ketoconazole, medications for HIV, and clarithromycin) and should be not be used in individuals with a known heart problem called prolonged QT interval or with medications that prolong the QT interval.
Cialis is available in three strengths: 5mg, 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. The newest formulation of Cialis is the 5 mg dosage for daily use. The major advantage of daily dosing is that it allows for spontaneous sexual activity.
Stendra is available in three strengths: 50mg, 100 mg, and 200 mg. Stendra can work as rapidly as 15-30 minutes and can be taken with food or alcohol.
Side effects of Viagra, Levitra, Stendra, and Cialis include the following:
- Hypotension (a drop in blood pressure)
- Transient dizziness
- Facial flushing
- Nasal congestion
- Lower back pain (unique to Cialis)
- Visual disturbance (for example, blurred vision, increased light sensitivity, persistence of a bluish tinge, temporary loss of the ability to distinguish between blue and green)
- Priapism is a painful erection lasting six or more hours (a urologic emergency that requires you to call your doctor or go to an emergency department).
- Sudden decrease or loss of hearing
- Sudden loss of vision in one or both eyes
Your physician will determine which of these medications is most appropriate for you and the optimal dosage, which may vary with other health problems that you may have. 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.
Certain street drugs (for example, ecstasy) can also cause serious problems if taken with Viagra, Levitra, Stendra, or Cialis.