Passing out after taking sildenafil while intoxicated may be due to the fact that alcohol enhances the vasodilatory effect of sildenafil, resulting in low blood pressure leading to fainting. Sildenafil is mainly used in the clinical treatment of male erectile dysfunction, the mechanism of action is to inhibit the type 5 phosphodiesterase on the vascular smooth muscle, thus causing vasodilation, promoting the penile corpus cavernosum congestion, and promoting penile erection. The main adverse effects of sildenafil are cardiovascular adverse effects, mainly hypotension, tachycardia, angina pectoris, myocardial ischemia, which may also lead to heart failure and cardiac arrest. If you take sildenafil after drinking alcohol, the vasodilating effect of alcohol on the blood vessels will exacerbate the cardiovascular adverse effects of sildenafil, which may easily lead to low blood pressure, syncope and cerebrovascular accident. Therefore, sildenafil must be prohibited from drinking alcohol during the period of taking the drug, and once taken by mistake after drinking alcohol, must immediately go to the hospital, do not be negligent, so as to avoid adverse consequences.