Deciphers the medication tadalafil (Adcirca, Cialis), a drug used for the treatment of impotence (erectile dysfunction, ED). Dosage, side effects, and drug interaction information is provided. Cialis (tadalafil) is a prescription medication for erectile dysfunction (ED). It usually starts working within 30 minutes but can take up to 2 hours to fully set in. Be sure to follow your recommended Cialis dosage, whether you’re taking it every day or as needed. Cialis (Tadalafil) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Find patient medical information for Tadalafil (Cialis, Adcirca, and others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Brand names: Cialis, Adcirca. Tadalafil comes only as a tablet you take by mouth. Tadalafil is used to treat the symptoms of benign prostatic hyperplasia (BPH) and erectile dysfunction (ED). Benign prostatic hyperplasia (with or without concomitant erectile dysfunction) (Cialis): Oral: 5 mg once daily. Note: When tadalafil is used with finasteride to initiate BPH therapy, the recommended duration of therapy is ≤26 weeks. If you take tadalafil for pulmonary arterial hypertension, do not take Cialis® or other PDE5 inhibitors, including sildenafil (Revatio® or Viagra®) or vardenafil (Levitra®). Persons surnamed Cialis objected to Eli Lilly and Company's so naming the drug, but the company has maintained that the drug's trade name is unrelated to the surname. Cialis relaxes muscles of the blood vessels and increases blood flow to particular areas of the body. Cialis is used to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostatic hyperplasia. Learn about dosage, side effects, and more.