Instead, you can order Cialis through Felix and have it mailed to your home on a schedule that suits your needs. Several years ago, Cialis became available as a generic medication. The contents herein are for informational purposes only. You may also be able to get your prescription through an online healthcare provider, like Felix. Intake of organic nitrates, alpha-blockers, riociguat, and some other drugs is also a contraindication to Cialis use.You can take Cialis as needed, and only once every 24 hours. It typically takes 30 to 60 minutes for the medication to start working and has an effect that lasts up to 36 hours. . Cialis from Canada. Canada Drugs Online is proudly to serve you branded Cialis and generic Tadalafil from Canada manufactured by Lilly or Aurobingdo or Mylan. Please call . Tadalafil (Cialis) is a phosphodiesterase-5 enzyme (PDE-5) inhibitor. It works by blocking PDE This is a protein in your body that breaks down the molecules that .