Follow your doctor’s orders or the directions on the label. In some cases, ED can cause a strain on relationships and impact self-esteem. Avanafil Stendra. Will Cialis be prescription or OTC over-the-counter? When taken at the correct time and paired with sexual stimulation, the erection lasts long enough for successful intercourse.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 . Cialis can cost around $ to $ per month out of pocket, depending on the dosage you need. The first generic version of Cialis was released in October , and other manufacturers have released generic versions since then. This has increased market competition, driving prices down.  · For treatment of pulmonary arterial hypertension: Adults—40 milligrams (mg) (two 20 mg tablets) taken once a day. Take both tablets at the same time each day. Do not divide the 40 mg dose. Your doctor may adjust your dose as needed. Children—Use and dose must be determined by your doctor.