Lidocaine is not recommended for oral administration. Lidocaine is a commonly used local anesthetic in clinical practice, mostly for surface or infiltrative anesthesia of the skin and mucous membranes, with strong and long-lasting anesthetic effects, and can be injected or applied topically. Lidocaine is also used in the treatment of premature ventricular contractions, ventricular tachycardia and ventricular fibrillation in acute myocardial infarction. If lidocaine is administered orally, it may be absorbed into the blood through the oral mucosa or gastrointestinal tract. If the oral amount is particularly large, it may cause an overdose of lidocaine into the blood, resulting in a systemic toxic reaction, which in turn may lead to lower blood pressure and slower heart rate, requiring emergency resuscitation. In addition, because the action of local anesthetic on the mucous membrane may cause loss of reflex and paralysis of the recurrent laryngeal nerve, lidocaine taken orally may result in accidental aspiration or even asphyxiation. Therefore, lidocaine should be used under the guidance of a physician, and the indications and dosage of the drug should be strictly controlled.