What should I do if I forget a dose? Tadalafil works for these conditions by promoting muscle relaxation, which improves blood flow in PAH and urinary flow in BPH. Symptoms may include sudden urges to urinate urgency , difficulty in starting urination hesitancy , a weak urine stream, and more frequent urination — especially at night. It belongs to the drug class known as PDE5 inhibitors. If you ever need emergency medical treatment for a heart problem, the health care providers who treat you will need to know when you last took tadalafil. Ask your doctor if you are not sure whether any of your medications contain nitrates. Do not stop taking tadalafil without talking to your doctor.Brand names for tadalafil include Cialis. The cost for tadalafil oral tablet 5 mg is around $27 for a supply of 90 tablets, depending on the pharmacy you visit. , Target, WalMart Pharmacy, Duane Reade and 65, pharmacies nationwide. No manufacturer promotions could be found for this medication. Patient Assistance & Copay Programs for. Tadalafil (Cialis) is taken by mouth either as needed before sexual activity or once daily for erectile dysfunction (ED).It’s also taken once daily to treat symptoms from an enlarged prostate (benign prostatic hyperplasia, or BPH).Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this medication include . 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.