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. This medicine is available only with your doctor’s prescription. If you drink a large amount of alcohol more than five glasses of wine or five shots of whiskey while you are taking tadalafil you are more likely to experience certain side effects of tadalafil such as dizziness, headache, fast heartbeat, and low blood pressure. You’ll soon start receiving the latest Mayo Clinic health information you requested in your inbox. Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. Before taking tadalafil, tell your doctor and pharmacist if you are allergic to tadalafil, any other medications, or any of the ingredients in tadalafil tablets.Benign prostatic hyperplasia alone or with erectile dysfunction: The typical dose is 5 mg by mouth at the same time every day. Your dose might differ if you have liver or kidney problems, or if you’re taking certain medications.  · Cialis; Descriptions. Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The . Cialis is Food and Drug Administration (FDA) approved to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BHP). Generic tadalafil became more widely available after