Tadalafil has a molecular formula of C22H19N3O4 with a molecular weight of 389.4 and has been widely used to treat erectile dysfunction in men since 2003 under the trade name Cialis. In 2008, Eli Lilly sold the commercial development rights for the treatment of PAH to United Therapeutics. In June 2009, Tadanafil was approved by the FDA for the treatment of patients with pulmonary arterial hypertension (PAH) in the United States under the trade name Adcirca. Tadalafil was introduced in 2003 as a drug for the treatment of ED, and the effect of Chemicalbook was 30min after administration, but its best effect was 2h after the effect, the effect could last for 36h, and its effect was not affected by food. Tadanafil is administered in doses of 10 or 20mg, with the recommended initial dose of 10mg, depending on the patient's reaction and adverse reactions. Pre-market studies showed that after 12 weeks of oral administration of 10 or 20mg of tadalafil, response rates were 67% and 81%, respectively. Many studies have shown that tadanafil has a good effect on ED. Tadanafil is indicated for the treatment of erectile dysfunction (ED) and pulmonary hypertension in men