Do NOT use Cialis if:



* you are allergic to any ingredient in Cialis

* you have severe kidney problems and will be taking Cialis daily

* you have severe liver problems or certain hereditary degenerative eye problems (eg, retinitis pigmentosa)

* you have certain heart problems (eg, unstable angina, angina during sexual intercourse, severe heart failure, uncontrolled irregular heartbeat), low blood pressure, or uncontrolled high blood pressure

* you have had a heart attack within the past 90 days or a stroke within the past 6 months

* you are taking nitrates (eg, isosorbide, nitroglycerin) in any form (eg, tablet, capsule, patch, ointment) or nitroprusside

* you have been advised by your doctor to avoid sexual activity because of heart problems

* you use certain recreational drugs called "poppers" (eg, amyl nitrate, butyl nitrate)

Contact your doctor or health care provider right away if any of these apply to you.

Before using Cialis :

Some medical conditions may interact with Cialis . Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

* if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement

* if you have allergies to medicines, foods, or other substances

* if you have a deformed penis (eg, Peyronie disease, cavernosal fibrosis), blood problems (eg, sickle cell anemia, leukemia, multiple myeloma), or any other condition that may increase the risk of a prolonged erection (priapism)

* if you have a history of certain eye problems (eg, retinitis pigmentosa, sudden vision loss, optic neuropathy, macular degeneration)

* if you have a history of liver or kidney problems, dialysis, high or low blood pressure, ulcers, bleeding problems, blood vessel problems, heart problems (eg, heart failure, irregular heartbeat, aortic stenosis, angina), or blood vessel problems

* if you have a history of heart attack, stroke, or life-threatening irregular heartbeat

Some MEDICINES MAY INTERACT with Cialis . Tell your health care provider if you are taking any other medicines, especially any of the following:

* Alpha-blockers (eg, doxazosin), medicines for high blood pressure, nitrates (eg, isosorbide, nitroglycerin), or nitroprusside because severe low blood pressure with dizziness, lightheadedness, and fainting may occur

* Azole antifungals (eg, itraconazole), HIV protease inhibitors (eg, ritonavir), macrolide antibiotics (eg, erythromycin), or telithromycin because they may increase the risk of Cialis 's side effects

* Rifampin because it may decrease Cialis 's effectiveness

This may not be a complete list of all interactions that may occur. Ask your health care provider if Cialis may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.