indication

For the production of local anesthesia by infiltration and peripheral nerve block. They are not to be used for lumbar or caudal epidural anesthesia.

pharmacology

Chloroprocaine is an anesthetic agent indicated for production of local or regional anesthesia, particularly for oral surgery. Chloroprocaine (like cocaine) has the advantage of constricting blood vessels which reduces bleeding, unlike other local anesthetics like lidocaine. Chloroprocaine is an ester anesthetic.

mechanism of action

Chloroprocaine acts mainly by inhibiting sodium influx through voltage gated sodium channels in the neuronal cell membrane of peripheral nerves. When the influx of sodium is interrupted, an action potential cannot arise and signal conduction is thus inhibited. The receptor site is thought to be located at the cytoplasmic (inner) portion of the sodium channel. It is hypothesized that Chloroprocaine binds or antagonizes the function of N-methyl-D-aspartate (NMDA) receptors as well as nicotinic acetylcholine receptors and the serotonin receptor-ion channel complex.

toxicity

In mice, the intravenous LD₅₀ of chloroprocaine HCl is 97 mg/kg and the subcutaneous LD₅₀ of chloroprocaine HCl is 950 mg/kg.

biotransformation

Chloroprocaine is rapidly metabolized in plasma by hydrolysis of the ester linkage by pseudocholinesterase.

absorption

The rate of systemic absorption of local anesthetic drugs is dependent upon the total dose and concentration of drug administered, the route of administration, the vascularity of the administration site, and the presence or absence of epinephrine in the anesthetic injection.

half life

21 +/- 2 seconds

route of elimination

Chloroprocaine is rapidly metabolized in plasma by hydrolysis of the ester linkage by pseudocholinesterase. Urinary excretion is affected by urinary perfusion and factors affecting urinary pH.