The effect of nitroglycerin ointment applied to men lasts for about 20 minutes. Clinically nitroglycerin ointment can relax the anal sphincter, relieve spasm and reduce symptoms. Secondly, it can also relax the vascular smooth muscle, diastolic blood vessels, increase blood vessels local blood, promote the healing of ulcers. It is mainly used for the treatment of anal fissure in men and the relief of pain symptoms caused by anal fissure. After applied locally through the anus, the peak concentration of the drug can be reached in 3-10 minutes, and it will be gradually metabolized and excreted from the body in about 20 minutes. Therefore, a man who applies nitroglycerin ointment topically to the anus is usually able to maintain it for about 20 minutes. After topical application of this drug, there may be discomfort such as rectal bleeding, hypotension, and allergic skin reactions. It is also contraindicated in patients younger than 18 years of age, postural hypotension, cerebral hypoperfusion, and severe liver disease. For pregnant and lactating women should be used with caution. In the use of the time to pay attention to the local use of drugs, can not be taken orally. At the same time after using the drug need to wash their hands, to avoid the drug contact with the eyes and mouth, nose and other mucous membrane parts. If the condition requires the application of nitroglycerin ointment for treatment, it must be used in accordance with the doctor’s instructions, and should not be used without authorization to avoid causing adverse reactions.