It is not recommended to take sildenafil citrate tablets every day, and for patients who do need to take the drug, it is recommended to take it between about half an hour and four hours before intercourse. The drug is a selective inhibitor of cyclic guanosine monophosphate specific type 5 phosphodiesterase, which is one of the commonly used drugs for the treatment of erectile dysfunction in men. During administration, the drug may cause vasodilation in the body circulation, leading to a drop in prone blood pressure, which is also dangerous for patients. Therefore, it is not recommended for patients to take it on a daily basis. For patients who do need to take the medication, it can be taken about half an hour to four hours before intercourse. It is important for patients to note that if they have recently taken or are taking nitrate drugs, they should not use this medication to prevent the lowering of blood pressure from inducing a dangerous event. Therefore, in order to ensure the safety of medication, patients need to follow the doctor’s instructions to use the drug, do not arbitrarily use their own medicine.