An erection will not occur just by taking a pill. Stop using tadalafil and call your doctor at once if you have: heart attack symptoms–chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating; vision changes or sudden vision loss; ringing in your ears or sudden hearing loss; or an erection is painful or lasts longer than 4 hours prolonged erection can damage the penis. If you miss a dose of Adcirca or Alyq, take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Swallow it whole. Follow all directions on your prescription label and read all medication guides or instruction sheets. This is not a complete list of side effects and others may occur. What should I do if I missed a dose of Cialis Tadalafil?Cialis is a prescription medication containing the active ingredient tadalafil. Cialis belongs to a group of medications known as phosphodiesterase-5 (PDE-5) inhibitors. Healthcare providers commonly prescribe tadalafil to treat erectile dysfunction (ED).  · Is taking Cialis 40 mg daily safe? Medically reviewed by test1.ru Last updated on April 5, Official answer by test1.ru The recommended daily dosage of Cialis is 20mg. By taking a high dose you increase the risks of severe side effects. test1.ru test1.ru . Reviewed: March 5, The Cialis brand of tadalafil is used in men to treat erectile dysfunction (impotence) and symptoms of benign prostatic hypertrophy (enlarged prostate). Adcirca and Alyq.