(1) procaine hydrochloride. This product has weak permeability to mucosa and is generally not used for topical anesthesia. After being injected into the tissue, it can be anesthetized in a few minutes. However, because this product has the function of dilating blood vessels, it can increase the amount of bleeding in the operating area and accelerate the absorption of local anesthetics, thus making local anesthesia ineffective. In order to prolong the action time of local anesthesia and reduce drug absorption, a small amount of epinephrine (0. 1% epinephrine solution 0.5 ml) is often added to this drug solution. Intravenous injection of low concentration procaine has mild inhibitory, analgesic, spasmolytic and antiallergic effects on the central nervous system. It also has inhibitory effect on cardiovascular system. Can be used for treating tachycardia and arrhythmia. Usage and dosage: 0.25% ~ 0.5% solution is used for infiltration anesthesia or local sealing; 2% ~ 5% solution is used for conduction anesthesia and epidural anesthesia.

(2) lidocaine. Compared with procaine, this product has stronger local anesthesia and penetration, faster action, wider diffusion, no irritation to tissues and longer local anesthesia duration (1 ~ 2 hours). Usage and dosage: 2% ~ 5% solution for topical anesthesia; 0.25% ~ 0.5% solution is used for infiltration anesthesia; 2% solution for conduction anesthesia; 0.5% solution was used for epidural anesthesia.