2024年3月22日 · Related/similar drugs. tamsulosin, finasteride, sildenafil, tadalafil, Flomax, doxazosin, Cialis, Viagra, alprostadil, Adcirca. What happens if I miss a dose? If tadalafil is used as needed, you are not likely to be on a dosing schedule. If you take tadalafil every day and you miss a dose, take the missed dose as soon as you remember.