Before taking tadalafil, tell your doctor and pharmacist if you are allergic to tadalafil, any other medications, or any of the ingredients in tadalafil tablets. If you have certain health conditions or are taking certain medications, your doctor may tell you to take tadalafil less often or may prescribe a lower dose to be taken once a day. This is not a complete list of interactions; others may occur with Cialis. Tadalafil works for these conditions by promoting muscle relaxation, which improves blood flow in PAH and urinary flow in BPH. By doing so—combined with sexual stimulation—a cascade of events occurs that increases nitric oxide. With PAH, high blood pressure develops when a blockage in the arteries within the lung limits normal blood flow. Sexual activity may be a strain on your heart, especially if you have heart disease.Generic tadalafil pills are often less than half the price of Cialis. A study found that from to , the median price of Cialis jumped from $ to $ for 30 tablets. Generic brands. The drug comes in low-dose versions that can be taken daily. This means you can have sex at any time, rather than needing to take a pill from time to time as needed like other ED brands. The starting dose for daily-use Cialis is milligrams (mg). If that doesn’t work, you can increase your daily dose up to 5 mg. Cialis comes as oral tablets that are available in four strengths: milligrams (mg), 5 mg, 10 mg, and 20 mg. Recommended dosage for Cialis Typically, .