After taking a single tablet, some of the active ingredient of Cialis remains in your body for more than 2 days. You can avoid potentially awkward encounters at a physical store. Ask your healthcare professional how you should dispose of any medicine you do not use. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. If you are already taking medication to treat BPH, your doctor may tell you to stop taking your other medication at least one day before starting treatment with tadalafil. · Cialis; Descriptions. Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where . It is available in both brand and generic versions. Cialis is not covered by most Medicare and insurance plans, but manufacturer and pharmacy coupons can help offset the cost. Prices Medicare Drug Info Side Effects Images. Cialis (tadalafil) is a moderately priced drug used to treat erection problems in men. It may also be used to treat the. Tadalafil (Cialis) is available in generic and brand versions in several doses as an oral tablet. You can take Cialis as needed or once a day, depending on the dose and how it’s prescribed.