Cialis (tadalafil) may cause headaches, stomach upset, and back pain. It can also cause prolonged erections in some people. Review the side effects of Cialis and learn how to manage them. This guide covers common tadalafil side effects, why they happen, how to reduce each one, the rare warning signs, the all-important nitrate interaction, and who should avoid the drug entirely. Although rare, Cialis can cause serious side effects like sudden hearing loss or vision changes, chest pain, or a prolonged erection that requires immediate medical attention. The risk of. Tadalafil increases blood flow to particular areas of the body and is used to treat erectile dysfunction. Learn about side effects, interactions and indications. Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco. Cialis, a medication for erectile dysfunction and benign prostatic hyperplasia, may cause common side effects, such as headaches, upset stomach, and muscle pain, which are usually temporary. Learn about the side effects of tadalafil, from common to rare, for consumers and healthcare professionals. Tadalafil's most common side effects - headache, flushing, indigestion, back pain, and nasal congestion - are generally milder than those of sildenafil (Viagra) but longer-lasting, reflecting the drug's 36-hour duration of action. What are the serious side effects of tadalafil? While less common, the most serious side effects of tadalafil are described below, along with what to do if they happen. Tadalafil is prescribed for benign prostatic hyperplasia, erectile dysfunction, and pulmonary arterial hypertension. Learn about side effects and more.