1. It is strictly forbidden to use with nitrate drugs (including nitroglycerin, cardiac pain, Lunan Xinkang) at the same time, otherwise it will make the blood pressure drop sharply and cause sudden death. 2. Contraindicated for hypotension, refractory arrhythmia, refractory hypertension, stroke or myocardial infarction within the last 6 months; or taking alpha-blockers, etc. 3. If you have any of the following diseases or conditions, be sure to inform your doctor before deciding whether you can use the medication. These include heart problems, stroke, high or low blood pressure, retinitis pigmentosa, kidney or liver disease, blood disorders (e.g. sickle cell anemia, leukemia), allergy to ingredients of Viagra-type drugs, peptic ulcer or other bleeding conditions. 4. You should not drink alcohol before or after taking the drug, and you should not take a bath.