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. Do not take a double dose or more than one dose per day to make up for a missed one. Symptoms may include sudden urges to urinate urgency , difficulty in starting urination hesitancy , a weak urine stream, and more frequent urination — especially at night. Tadalafil comes as a tablet to take by mouth. One advantage Cialis has over Viagra and Levitra is its Tadalafil is in a class of medications called phosphodiesterase PDE inhibitors. Psychological factors like stress, depression, or anxiety can also contribute.headache *. upset stomach. runny nose. back pain *. upper respiratory infection. heartburn *. muscle pain. For a list of side effects reported by people taking Cialis in clinical trials, including. Tadalafil is a medicine used to treat erectile dysfunction (ED, also called impotence) and problems with urination caused by an enlarged prostate (benign prostatic hypertrophy or BPH). It is sometimes known by its generic name tadalafil, and sometimes known by its trade name, Cialis. There are also other brands of this medicine available. The recommended starting dose for Cialis intended for once daily use is mg, take at the same time each day, without regard to timing of sexual activity. This may be increased to 5mg/day based on need and tolerability. May be taken with or without food. Cialis is available as a generic, under the name tadalafil. 3.