It is important to tell your doctor about any heart problems you have now or may have had in the past. Take both tablets at the same time each day. Take tadalafil exactly as directed. Talk to your doctor about which dosing schedule is right for you. If you take nitrates in any form, or are on treatment for pulmonary hypertension , you should not take tadalafil. In , Pfizer scientists discovered that sildenafil, which also inhibits the PDE5 enzyme, caused penile erection in males participating in a clinical study of a heart medicine. You should take tadalafil one time a day.Tadalafil Brand names: Cialis, Adcirca. Tadalafil. Find out how tadalafil treats erectile dysfunction, pulmonary hypertension and benign prostate enlargement, and how to take it. Tadalafil Brand names: Cialis, Adcirca. Tadalafil. Find out how tadalafil treats erectile dysfunction, pulmonary hypertension and benign prostate enlargement, and how to take it. Cialis (tadalafil) is an oral medication that treats erectile dysfunction (ED). One dose of Cialis lasts longer than a dose of the well-known Viagra (sildenafil). You can take Cialis when you need it, typically 30 minutes before sex. If that doesn’t work for you, another option is taking a low-dose pill every day for ongoing erectile support.