There may be rare occurrences of priapism or painful, prolonged erections. You can report an adverse event either online, by regular mail or by fax, using the contact information at the bottom of this page. Cialis will be available as oral tablets in 5mg, 10mg and 20mg strengths. When will Cialis be available to pharmacies? What Is Cialis? What should I talk to my doctor about when considering if Cialis is right for me? ED occurs more frequently in older men.Roman sells the following versions of Cialis: Generic: available in tablets of 5, 10, and 20 milligrams (mg), starting from $11 Daily Generic: available in doses of and 5 mg at $8 Branded. Tadalafil is a medicine used to treat erectile dysfunction (ED, also called impotence) and problems with urination caused by an enlarged prostate (benign prostatic hypertrophy or BPH). It is sometimes known by its generic name tadalafil, and sometimes known by its trade name, Cialis. There are also other brands of this medicine available.  · Below, we’ll detail nine of the most common tadalafil interactions to keep in mind. 1. Nitrates. Nitrates are used to treat and prevent angina (chest pain) caused by heart disease. Examples include nitroglycerin (Nitrostat), isosorbide mononitrate (Monoket), and isosorbide dinitrate (Isordil).