What is Cialis used for?
Cialis is a prescription medicine taken by mouth for the treatment of erectile dysfunction (ED) in men. ED is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. A man who has trouble getting or keeping an erection should see his doctor for help if the condition bothers him. Cialis may help a man with ED get and keep an erection when he is sexually excited.

Cialis does not:

cure ED
increase a man’s sexual desire
protect a man or his partner from sexually transmitted diseases, including HIV. Speak to your doctor about ways to guard against sexually transmitted diseases.
serve as a male form of birth control.

Cialis is only for men with ED. Cialis is not for women or children. Cialis must be used only under a doctor’s care.

Who should not use Cialis?

Special Warnings with Cialis:

Cialis can cause your blood pressure to drop suddenly to an unsafe level if it is taken with certain other medicines such as nitrates and alpha-blockers, and recreational drugs that contain nitrates called "poppers". A sudden drop in your blood pressure could cause you to become dizzy, faint, or have a heart attack or stroke.

Tell all your healthcare providers that you take Cialis. If you need emergency medical care for a heart problem, it will be important for your healthcare provider to know when you last took Cialis.

Who should not take Cialis?

Do not take Cialis if you:

take any medicines called “nitrates”
use recreational drugs called "poppers like amyl nitrate and butyl nitrate
take medicines called “alpha blockers”, other than Flomax® ?0.4 mg daily.
have been told by your healthcare provider to not have sexual activity because of health problems.
are allergic to Cialis or any of its ingredients.

What should I tell my health care provider?

Tell your health care provider if you:

• Have heart problems such as angina, heart failure, irregular heartbeats, or have had a heart attack.
• Have low blood pressure or have high blood pressure that is not controlled.
• Have had a stroke.
• Have liver problems.
• Have kidney problems or require dialysis.
• Have retinitis pigmentosa, a rare genetic (runs in families) eye disease.
• Have stomach ulcers.
• Have a bleeding problem.
• Have a deformed penis shape or Peyronie’s disease.
• Have had an erection that lasted more than 4 hours.
• Have blood cell problems such as sickle cell anemia, multiple myeloma, or leukemia.

Tell your doctor about all the medicines you take including prescription and non-prescription.

medicines, vitamins, and herbal supplements. Cialis and other medicines may affect each other.

Especially tell your doctor if you take any of the following:

• Medicines called nitrates.
• Medicines called alpha blockers. These include Hytrin® (terazosin), Flomax® (tamsulosin), Cardura® (doxazosin), Minipress® (prazosin) or Uroxatral (alfuzosin).
• Ritonavir (Norvir®) or indinavir. (Crixivan®)
• Ketoconazole or itraconazole. (such as Nizoral® or Sporanox®)
• Erythromycin.
• Other medicines or treatments for ED.

What are some possible side effects of Cialis?
(This list is NOT a complete list of side effects reported with Cialis. Your health care provider can discuss with you a more complete list of side effects.)

The most common side effects with Cialis are:

• Headache.
• Indigestion.
• Back pain.
• Muscle aches.
• Flushing.
• Stuffy or runny nose.

Cialis may uncommonly cause:

• an erection that won’t go away. (priapism)
• vision changes, such as seeing a blue tinge to objects or having difficulty telling the difference between the colors blue and green.