Phosphodiesterase-5 inhibitors are a class of drugs that selectively inhibit phosphodiesterase activity, mainly with positive inotropic and vasodilatory effects, and are generally used in the treatment of erectile dysfunction in men, as well as cardiovascular disease. However, patients need to take the drug strictly under the guidance of professional doctors, pay attention to the contraindications and avoid adverse reactions. Drug efficacy 1, erectile dysfunction: the current drug of choice for the treatment of erectile dysfunction of the penis is usually phosphodiesterase-5 inhibitors, mainly sildenafil, vardenafil and tadalafil three drugs, generally with fewer side effects and significant results. There are usually short-acting and long-acting, but all can relax the smooth muscle, making more blood flow into the cavernous body of the penis, thus promoting cavernous congestion to achieve a rapid erection; 2, cardiovascular disease: common drugs such as milrinone, aminon, cilostazol, etc., can play a vasodilator, positive inotropic effect to increase myocardial contractility, reduce pulmonary artery pressure, and restore the function of the heart and lungs. Therefore, it can be generally used to treat heart failure and improve the symptoms of chest tightness, shortness of breath and dyspnea in heart failure patients, as well as coronary artery disease and angina pectoris. Precautions 1, prohibit the combination with such as isosorbide mononitrate, isosorbide nitrate, nitroglycerin and other nitrate drugs, to avoid causing intractable hypotension and other adverse consequences; 2, safer when combined with anti-hypertensive drugs, can play a slight synergistic effect, will not increase adverse reactions; 3, with the treatment of prostatitis, prostate hypertrophy drugs, must be used strictly under the guidance of a professional doctor The actual fact is that you can find a lot of people who are not able to get a good deal on a lot of things. You must reduce the dose or stagger the time of oral intake in accordance with medical advice or instructions to avoid adverse reactions.