Which Is More Effective? Ask your doctor if you are not sure whether any of your medications contain nitrates. Share personal information without ensuring the site is secure. Potential Side Effects and Interactions While Cialis is generally safe, like all medications, it can have side effects. 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. Tadalafil is sometimes taken as needed, usually at least 30 minutes before sexual activity and not more often than once every 24 hours. Tadalafil works for these conditions by promoting muscle relaxation, which improves blood flow in PAH and urinary flow in BPH.How much does tadalafil or cialis cost near you? Find the best tadalafil or cialis prices near you now with our cost comparison tool and start saving today. (BRAND) CIALIS; Form Tablet. Tablet; Dosage 5 MG. 20 MG; 5 MG; 10 MG; MG; Quantity 30 tablets. 30 tablets; 90 tablets; 10 tablets; 60 tablets; 15 tablets; Custom Qty; Location. Low price Walmart $ retail Save 94% $ Get free savings Walgreens $ retail Save 89% $ Get free savings. Cialis (tadalafil) is a member of the impotence agents drug class and is commonly used for Benign Prostatic Hyperplasia, and Erectile Dysfunction. The cost for Cialis oral tablet .