To treat erectile dysfunction EDyour doctor may have you take Cialis only as needed before sexual activity. In this case, Cialis may keep working for up to 36 hours in helping you have and maintain erections during that time. Therefore, it will continue to work throughout the day. Cialis may treatment for Erection Problem be used off-label for other conditions. Cialis is approved by the FDA to treat the symptoms of benign prostatic hyperplasia. BPH is a condition that occurs in men as they weak erection. As the prostate gland gets bigger, Sildenafil, it begins to push on your bladder. So eventually you may experience symptoms of BPH, including:. Cialis was an effective medication to treat symptoms of BPH in clinical trials. The symptoms included urinary urgency sudden need to urinateweak urine stream, and straining to urinate.