1. Local anesthetics block the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, slowing the propagation of the nerve impulse, and reducing the rate of rising of the action potential. In general, the progression of anesthesia is related to the diameter, myelination, and conduction velocity of affected nerve fibers. Clinically, the order of a loss of nerve function is as follows: pain, temperature, touch, proprioception, and skeletal muscle tone.

2. Mepivacaine hydrochloride of Absorption
Absorbed locally. The rate of systemic absorption of local anesthetics is dependent upon the total dose and concentration of the drug administered, the route of administration, the vascularity of the administration site, and the presence or absence in the anesthetic solution.

3. Rapidly metabolized, with only a small percentage of the anesthetic (5 percent to 10 percent) being excreted unchanged in the urine. The liver is the principal site of metabolism, with over 50% of the administered dose being excreted into the bile as metabolites.

4. Route of elimination. It is rapidly metabolized, with only a small percentage of the anesthetic (5 percent to 10 percent) being excreted unchanged in the urine. The liver is the principal site of metabolism, with over 50% of the administered dose being excreted into the bile as metabolites.