You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail. If approved, the provider will issue a prescription. Often, these are prescribed for chest pain called angina. Oral ED medicines might not work or might be dangerous if you also take any of the following: Nitrate medicines. Cialis: Is one right for you?How Cialis Works. Tadalafil and other PDE5 inhibitors primarily work by inducing muscle relaxation. Tadalafil stops the breakdown of a chemical responsible for relaxing muscles. In ED and PAH, the drug targets muscle cells in blood vessels. When the blood vessel muscle cells relax, this expands the vessel and increases blood flow; this . Learn more about Cialis oral. 1. This is a generic drug. The average cost for 30 Tablet(s), 5mg each of the generic (tadalafil) is $ You can buy tadalafil at the discounted price of $ by using the MDRx coupon, a savings of 93%. Even if this drug is covered by Medicare or your insurance, we recommend you compare prices. CIALIS for Use as Needed. Creatinine clearance 30 to 50 mL/min: A starting dose of 5 mg not more than once per day is recommended, and the maximum dose is 10 mg not more than once in every 48 hours. Creatinine clearance less than 30 mL/min or on hemodialysis: The maximum dose is 5 mg not more than once in every 72 hours [see .