Chloroprocaine (trade name Nesacaine, Nesacaine-MPF) (often in the hydrochloride salt form as the aforementioned trade names) is a local anesthetic given by injection during surgical procedures and labor and delivery. Chloroprocaine vasodilates; this is in contrast to cocaine which vasoconstricts. Chloroprocaine is an ester anesthetic. Medical uses
Chloroprocaine is used for regional anaesthesia including spinal anaesthesia, caudal anaesthesia and epidural anesthesiaIt is also indicated for local anaesthesia including brachial plexus block, cervical nerve block, occipital nerve block. mandibular nerve block or maxillary nerve block for dental anesthesia, ophthalmic anesthesia via infraorbital nerve block, ulnar nerve block, paravertebral block, intercostal nerve block, sciatic nerve block, stellate ganglion block, lumbar sympathetic block and interdigital block.It is also used for obstetric anesthesia including pudendal nerve block and paracervical block.Chloroprocaine is also indicated for ocular surface anesthesia. Subarachnoid block
Chloroprocaine was developed to meet the need for a short-acting spinal anaesthetic that is reliable and has a favourable safety profile to support the growing need for day-case surgery. Licensed in Europe for surgical procedures up to 40 minutes, chloroprocaine is an ester-type local anaesthetic with the shortest duration of action of all the established local anaesthetics. It has a significantly shorter duration of action than lidocaine and is significantly less toxic. Chloroprocaine has a motor block lasting for 40 minutes, a rapid onset time of 3–5 minutes (9.6 min ± 7.3 min at 40 mg dose; 7.9 min ± 6.0 min at 50 mg dose) and a time to ambulation of 90 minutes without complications, especially lacking transient neurologic symptomatology.
Chloroprocaine (pKa 8.7) is the drug of choice for epidural analgesia and a decompensating fetus, because it does not participate in ion trapping. Placental transfer of 2-chloroprocaine is not influenced by fetal acidosis.The in vitro half-life of chloroprocaine is 21 seconds for maternal and 43 seconds for fetal blood. In patients who are homozygous atypical for plasma cholinesterase, chloroprocaine typically exists for two minutes in circulation. Synthesis
The hydrochloride salt of 4-amino-2-chlorobenzoyl chloride is made by the reaction of 2-chloro-4-aminobenzoic acid with thionyl chloride. Synthesis of this drug is then accomplished by directly reacting the product of the last step with the hydrochloride salt of 2-diethylaminoethanol. References
External links
"Chloroprocaine". Drug Information Portal. U.S. National Library of Medicine.