At present, the western medicine for the treatment of impotence is mainly type 5 phosphodiesterase inhibitors, and the commonly used drugs are sildenafil, tadalafil, avanafil and so on. Phosphodiesterase type 5 is mainly found in the smooth muscle of the corpus cavernosum, and the inhibition of this enzyme can promote the diastole of the corpus cavernosum smooth muscle cells and increase the perfusion of the corpus cavernosum, which can effectively improve the erectile function. Inhibitors of this enzyme include tadalafil, sildenafil, avanafil, etc. The effectiveness rate of this enzyme inhibitor can reach 80% for impotence caused by organic lesions, and even higher for impotence caused by psychological reasons. Adverse effects commonly seen with phosphodiesterase inhibitor type 5 include dyspepsia, dizziness, visual abnormalities, back pain, myalgia, facial flushing, headache, etc. Allergy to this drug is contraindicated, and this drug cannot be used in combination with nitrate drugs. Please take the drug under the guidance of a physician, do not use the drug indiscriminately.