If you experience chest pain, dizziness, or nausea during sexual activity, call your doctor immediately or get emergency medical treatment, and avoid sexual activity until your doctor tells you otherwise. Ask your pharmacist for a list of the ingredients. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Without physical action to the penis, such as that occurring during sexual intercourse, tadalafil will not work to cause an erection. Sorry something went wrong with your subscription Please, try again in a couple of minutes Retry. · Cialis is used in adult males.* It belongs to a group of drugs called phosphodiesterase 5 (PDE5) inhibitors. These drugs treat erectile dysfunction (ED) by relaxing blood vessels to increase. 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. Cialis works by increasing blood flow to the penis to help a person get and maintain an erection. It also blocks the PDE5 enzyme, which enhances the effects of nitric oxide (NO). NO activates a.