Cialis is a phosphodiesterase inhibitor. It works by helping to increase blood flow into the penis during sexual stimulation. This helps you to achieve and maintain an erection.
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
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