Chloroprocaine (trade name Nesacaine, Nesacaine-MPF) (often in the hydrochloride salt form as the aforementioned trade names) is a

local anesthetic A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general an ...

given by

injection Injection or injected may refer to: Science and technology * Injective function, a mathematical function mapping distinct arguments to distinct values * Injection (medicine), insertion of liquid into the body with a syringe * Injection, in broadca ...

during

surgical procedures Many Surgery, surgical procedure names can be broken into parts to indicate the meaning. For example, in gastrectomy, "ectomy" is a suffix (linguistics), suffix meaning the removal of a part of the body. "Gastro-" means stomach. Thus, ''gastrectom ...

and

labor and delivery Childbirth, also known as labour and delivery, is the ending of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million births globall ...

. Chloroprocaine vasodilates; this is in contrast to cocaine which vasoconstricts. Chloroprocaine is an ester anesthetic.

Medical uses

Chloroprocaine is used for

regional anaesthesia Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It ...

including

spinal anaesthesia Spinal anaesthesia (or spinal anesthesia), also called spinal block, subarachnoid block, intradural block and intrathecal block, is a form of neuraxial regional anaesthesia involving the injection of a local anaesthetic or opioid into the subarac ...

, caudal anaesthesia and

epidural anesthesia Epidural administration (from Ancient Greek ἐπί, , upon" + ''dura mater'') is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians and ...

It is also indicated for

local anaesthesia Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It ...

including

brachial plexus block Brachial plexus block is a regional anesthesia technique that is sometimes employed as an alternative or as an adjunct to general anesthesia for surgery of the upper extremity. This technique involves the injection of local anesthetic agents in cl ...

cervical nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the ...

block, occipital nerve block.

mandibular nerve In neuroanatomy, the mandibular nerve (V) is the largest of the three divisions of the trigeminal nerve, the fifth cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which contain only aff ...

block or

maxillary nerve In neuroanatomy, the maxillary nerve (V) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate a ...

block for

dental anesthesia Dental anesthesia (or dental anaesthesia) is the application of anesthesia to dentistry. It includes local anesthetics, sedation, and general anesthesia. Local anesthetic agents in dentistry In dentistry, the most commonly used local anesthetic ...

, ophthalmic anesthesia via

infraorbital nerve The infraorbital nerve is a branch of the maxillary nerve, itself a branch of the trigeminal nerve (CN V). It travels through the orbit and enters the infraorbital canal to exit onto the face through the infraorbital foramen. It provides sensory ...

block,

ulnar nerve In human anatomy, the ulnar nerve is a nerve that runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is ...

block, paravertebral block,

intercostal nerve block Intercostal nerve block (abbreviated ICNB) is a nerve block which temporarily or permanently interrupts the flow of signals along an intercostal nerve, usually performed to relieve pain. Uses An ICNB relieves the pain associated with injured i ...

sciatic nerve block A sciatic nerve block is a nerve block that uses local anesthetic to achieve analgesia in the leg. The block works by affecting the sciatic nerve and is used for surgeries at or below the knee. The sciatic nerve is located in the gluteus maximus ...

stellate ganglion The stellate ganglion (or cervicothoracic ganglion) is a sympathetic ganglion formed by the fusion of the inferior cervical ganglion and the first thoracic (superior thoracic sympathetic) ganglion, which exists in 80% of people. Sometimes, the seco ...

block,

lumbar In tetrapod anatomy, lumbar is an adjective that means ''of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum.'' The lumbar region is sometimes referred to as the lower spine, or as an area of the back i ...

sympathetic block and interdigital block. It is also used for

obstetric anesthesia Obstetric anesthesia or obstetric anesthesiology, also known as ob-gyn anesthesia or ob-gyn anesthesiology, is a sub-specialty of anesthesiology that provides peripartum (time directly preceding, during or following childbirth) pain relief (analges ...

including

pudendal nerve block Pudendal anesthesia, also known as a pudendal block, or saddle block, is a form of local anesthesia commonly used in the practice of obstetrics to relieve pain during the delivery of baby by forceps. The pudendal nerve block prevents fainting durin ...

and

paracervical block A paracervical block is an anesthetic procedure used in obstetrics and gynecology, in which a local anesthetic is injected into between two and six sites at a depth of 3–7 mm alongside the vaginal portion of the cervix in the vaginal fornices ...

. 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. These data are based upon a retrospective review of 672 patients suitable for spinal anaesthesia in surgical procedures less than 60 minutes' duration using 30–40 mg chloroprocaine. The results showed good surgical anaesthesia, a fast onset time, and postoperative mobilization after 90 minutes without complications. The use of chloroprocaine in the subarachnoid space has been questioned. In the early 1980s, several cases were reported of neurological deficits after inadvertent intrathecal injections intended for epidural delivery. These doses were an order of magnitude higher than is currently used for intrathecal delivery. It is also thought that these deficits were also related to the preservative

sodium bisulfate Sodium bisulfate, also known as sodium hydrogen sulfate, is the sodium salt of the bisulfate anion, with the molecular formula NaHSO4. Sodium bisulfate is an acid salt formed by partial neutralization of sulfuric acid by an equivalent of sodium b ...

, although this is also controversial. In recent years, several studies have been published on the safe use of intrathecal chloroprocaine when appropriate dosage is used and with preservative-free preparations. It is currently approved for intrathecal use in the United States and in Europe.

Obstetrics

Amide-linked local anesthetic agents, such as

lidocaine Lidocaine, also known as lignocaine and sold under the brand name Xylocaine among others, is a local anesthetic of the amino amide type. It is also used to treat ventricular tachycardia. When used for local anaesthesia or in nerve blocks, lidoca ...

and

bupivacaine Bupivacaine, marketed under the brand name Marcaine among others, is a medication used to decrease feeling in a specific area. In nerve blocks, it is injected around a nerve that supplies the area, or into the spinal canal's epidural space. It ...

, can become "trapped" in their ionized forms on the fetal side of the

placenta The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mater ...

, so their net transfer across the placenta is increased. An ester-linked local anesthetic agent, such as 2-chloroprocaine, is rapidly metabolized, and placental transfer is limited. Since the metabolism of 2-chloroprocaine by fetal plasma is slower than in maternal plasma, the potential for ion trapping exists. Fetal pH is slightly lower than maternal (7.32 to 7.38), thus most unionized drugs are "ion trapped" to a degree, even in a healthy fetus. Chloroprocaine (pKa 8.7) is the drug of choice for

epidural Epidural administration (from Ancient Greek ἐπί, , upon" + ''dura mater'') is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians and ...

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 Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...

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.Hughes: Anesthesia for Obstetrics, 4th ed, p75.

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 Diethylethanolamine (DEAE) is a chemical compound with the molecular formula C6H15NO. It is used as a Precursor (chemistry), precursor in the production of a variety of chemical commodities such as the local anesthetic procaine. It can be reacte ...

References

External links

* * {{Portal bar , Medicine Local anesthetics 4-Aminobenzoate esters Chlorobenzenes Diethylamino compounds