This increased blood flow can cause an erection. It should be noted, however, that the patent for any new drug, like Viagra, for instance, has an expiry. Tadalafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus HIV. The rising price of Cialis can be attributed to several factors. There was no pattern in the occurrence of side effects observed when using the drug was used casually. Talk to your doctor about which dosing schedule is right for you. Tadalafil Cialis is used to treat erectile dysfunction ED, impotence; inability to get or keep an erection , and the symptoms of benign prostatic hyperplasia BPH; an enlarged prostate which include difficulty urinating hesitation, dribbling, weak stream, and incomplete bladder emptying , painful urination, and urinary frequency and urgency in adult men.Tadalafil is also generally less expensive than Cialis. Is there an over-the-counter Cialis? To be used legally in the United States, ED medications must be purchased with an in-state prescription. To find out how the costs of Cialis, Adcirca, Alyq, and tadalafil compare, talk with your doctor, pharmacist, or insurance provider. Tadalafil (Cialis) is taken by mouth either as needed before sexual activity or once daily for erectile dysfunction (ED).It’s also taken once daily to treat symptoms from an enlarged prostate (benign prostatic hyperplasia, or BPH).Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication include .