Lidocaine is a local anesthetic drug and is commonly used in clinical dosage forms such as creams and injections. Contraindications to lidocaine are mainly allergy to the drug is prohibited. Contraindications for cream include a history of allergy to amide local anesthetics, hypersensitivity to proparacaine or lidocaine, and congenital or idiopathic methemoglobinemia. Contraindications to injections include intravenous contraindication in patients with hypersensitivity to local anesthetics, acute cardiogenic ischemic syndrome, preexcitation syndrome, and severe cardiac conduction block. It should be used with caution in the presence of severe hepatic disease that affects drug metabolism, and should also be used with caution in pregnant as well as lactating women. This product is mainly used for infiltration anesthesia, epidural anesthesia, surface anesthesia and nerve conduction block, etc. Possible adverse reactions include dizziness, dizziness, nausea and vomiting. The drug needs to be used under the guidance of a professional doctor and not blindly used on its own.