Benadryl Tablet is an antihypertensive drug whose side effects mainly include cough and insomnia. The side effects of Benadryl Tablet are mainly manifested as dizziness, head stuffiness, cough, insomnia, etc. It can also be manifested as symptomatic low blood pressure, syncope, tremor and decreased libido, skin manifestations can be blushing, fever, rash, skin nodules, etc. Digestive system can be manifested as dry mouth, nausea, abdominal pain, constipation, etc. It can also be manifested as hypokalemia, malnutrition, etc. Benadryl tablets should be used under the guidance of a doctor, for the drug allergy, renal failure, renal artery stenosis is prohibited to use the drug. Therefore, Benadryl tablets should be taken at any time to monitor the changes in blood pressure, if there is any discomfort, you should consult a doctor in time.