Read more on male sexual health on the Sexual Health Australia site. This information is reviewed by a licensed practitioner who will assess your eligibility for the medication. People taking nitrates like nitroglycerin Nitrostat or isosorbide mononitrate Imdur should not take PDE5 inhibitors, as doing so could result in a dangerous drop in blood pressure. What important information should you know about Cialis? Tell your healthcare provider that you take Cialis. Soon, in , ICOS received a patent for compound IC structurally unlike sildenafil and vardenafil , and Phase 1 clinical trials began in Viagra, Cialis, sildenafil, tadalafil: Yes: Lemonaid Best for Cialis: Starting at $2 to $8 per pill: Yes: Sildenafil, tadalafil (as-needed and daily) Yes: Roman Best for Viagra: $8 to $44 per . 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 .  · But on average, its effects start to lessen 2 to 3 hours after you take a dose. The typical dose for once-daily Cialis for ED is milligrams (mg) to 5 mg. When used as needed for ED, the usual.