How should this medicine be used? Cialis can last in the system for up to 36 hours. Other uses for this medicine This medication may be prescribed for other uses; ask your doctor or pharmacist for more information. You can see an in-person provider or speak with a doctor virtually. Cialis can also interact with other medications, including nitrates and blood pressure medications.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. Side Effects. Headache, stomach upset, back pain, muscle pain, stuffy nose, flushing, or dizziness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. To. C 20 Pill – yellow oval, 12mm. Generic Name: tadalafil Pill with imprint C 20 is Yellow, Oval and has been identified as Cialis 20 mg. It is supplied by Lilly, Eli and Company. Cialis is used in the treatment of Benign Prostatic Hyperplasia; Erectile Dysfunction and belongs to the drug class impotence test1.ru is no proven risk in humans during pregnancy.