Cialis is the trade name, generic name of tadalafil tablets, there are certain side effects, such as neurological side effects, gastrointestinal side effects, ocular side effects, cardiovascular side effects, and so on. 1. Patients may experience neurological side effects such as transient ischemic attack, fainting, sleep disorder, migraine, and nervousness. 2. Gastrointestinal side effects such as loss of appetite, anorexia, diarrhea, and abdominal pain may occur. 3. Some patients experience side effects such as conjunctival congestion, eyelid swelling, eye pain, and blurred vision. 4. Some patients may experience cardiovascular system side effects such as angina pectoris, chest pain, arrhythmia, rapid heart rate, hypotension, sudden cardiac death, myocardial infarction. Tadalafil tablets should be used under medical supervision. Tadalafil tablets are strictly prohibited for patients who are taking any form of nitrate medication. Tadalafil tablets should not be taken by patients with known hypersensitivity to tadalafil.