Side effects of Phenobarbamazine Hydrochloride Tablets include pupil constriction and reflex rapid heartbeat. The drug is commonly associated with miosis, reflex rapid heartbeat, postural hypotension, nasal congestion, dry mouth, and gastrointestinal irritation; less commonly, there are neurologic headaches, impotence, drowsiness, blurriness, and lethargy; and, occasionally, angina pectoris and myocardial infarction. Some patients may show signs of hypotension after administration of the drug, so blood pressure changes should be monitored after administration of the drug. Some patients may experience gastrointestinal irritation, such as stomach pain and upset stomach. Recent severe cardiovascular disease, or cerebrovascular accident is prohibited, or use with caution under the supervision of a physician. Prolonged oral administration of phenobenzylamine hydrochloride tablets is prone to gastrointestinal cancer, and patients are advised to take it with food or milk to minimize gastrointestinal irritation. During the period of taking the medicine, it is necessary to have a light and easy to digest diet, avoid spicy and stimulating food, avoid greasy food, avoid too salty food, and avoid overwork. The drug is a prescription drug and should be used under medical supervision.