Erectile dysfunction: Cialis, Viagra and Levitra ED treatment

There are only three oral drugs approved by FDA for the treatment of erectile dysfunction: Cialis, Levitra, and Viagra. All work by increasing blood flow to the penis so that when a man is sexually stimulated, it can get an erection.
What are the differences between Cialis, Levitra, and Viagra?

Cialis, Levitra, Viagra and works similar mechanism to cause erections. There are subtle differences in how long the drug works and how quickly it works. Levitra works a little longer than Viagra. Both occur in about 30 minutes. With Levitra, the effects last approximately 5 hours. With Viagra, the effects last approximately 4 hours.

Cialis works a bit faster (within about 15 minutes), and the effects last much longer – up to 36 hours in some cases.
If one of these drugs is not effective for erectile dysfunction, I try another?

Yes, but because these drugs work the same way, it is unlikely that you will have success with one if you have failed to achieve adequate erection with another.

Security measures which I should then take one of these drugs?

There are some situations in which these medications may not be safe to take. Before taking them, tell your doctor:
If you are allergic to any drugs, including Viagra or other ED drugs.
Any prescription or nonprescription medications you are currently taking, including herbal and dietary supplements.
If you are scheduled for surgery, including dental surgery.
If you take nitroglycerin or long-acting nitrate to treat chest pain. The combination of Cialis, Levitra or Viagra with these drugs can cause dangerously low blood pressure.
If you are taking alpha-blockers on blood pressure or prostate problems. The combination of Cialis and Levitra with these drugs can also cause dangerously low blood pressure.

In addition, always follow the directions on the prescription label carefully and ask your doctor or pharmacist to explain any part you do not understand. Take these drugs exactly as directed. Do not take more or less, or it more often than your doctor. Do not take this medication more frequently than once a day.
Who should not take Cialis, Levitra or Viagra?

If you have suffered a heart attack, stroke or life-threatening arrhythmia (irregular heartbeat) in the last 6 months you should discuss other options with your doctor. It is also advised to avoid these medicines if you have uncontrolled high or low blood pressure, or if you experience chest pain with sex.
What are the side effects for Cialis, Viagra and Levitra?

Side effects are rare but can occur. Side effects may include:
Headache
Upset stomach or ‘heartburn’
Flushing (warmth)
Stuffy
Changes in vision (color, glare)
Back pain (with Cialis)

Call your doctor if you suffer from severe forms of these symptoms, or if they do not go away after 4-8 hours.

Warning

Call your doctor or seek emergency treatment immediately if you experience any of the following symptoms:
Rash
Painful erections
Prolonged erections (longer than 4 hours)
Fainting
Chest pain
Itching or burning on urination

Stop taking these medicines and call a doctor or health care provider immediately if you experience sudden decrease or loss of vision in one or both eyes. Rare vision problem called NAION has been reported only a few men using these drugs. NAION (nonarteritic anterior ischemic optic neuropathy) causes a sudden loss of eyesight because blood flow is blocked to the optic nerve. People who have a higher chance for NAION include those who:
Are over 50 years
Smoke
They have heart disease
Have diabetes
You have high blood pressure
You have high cholesterol
Have certain eye problems
How should these drugs be stored?

These drugs should be kept in the original container and out of reach of children. Store them from excess heat and moisture (not in the bathroom). Discard all medicines that have expired or no longer needed.