Cialis Tadalafil

Usage: Used for the treatment of erectile dysfunction. Although sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) all work by inhibiting PDE5, it's pharmacologic distinction is its longer half-life (17.50 hours) - compared to sildenafil (4.0-5.0 hours) and vardenafil (4.0-5.0 hours) - resulting in longer duration of action, and so partly responsible for "The Weekend Pill" sobriquet. Furthermore, the longer half-life is the basis for current investigation of tadalafil's daily therapeutic use in relieving pulmonary arterial hypertension. Sildenafil is approved in several world regions as a thrice-daily therapy for pulmonary arterial hypertension.