Chloroprocaine, sold under the brand name Nesacaine among others is a

local anesthetic A local anesthetic (LA) is a medication that causes absence of all sensation (including pain) in a specific body part without loss of consciousness, providing local anesthesia, as opposed to a general anesthetic, which eliminates all sensati ...

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 ...

. It is used as the hydrochloride salt. Chloroprocaine is a local anesthetic.

Medical uses

Chloroprocaine (Nesacaine) is

indicated In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...

for the production of local anesthesia by infiltration and peripheral nerve block; and for the production of local anesthesia by infiltration, peripheral and central nerve block, including lumbar and caudal epidural blocks. Chloroprocaine (Clorotekal) is indicated for intrathecal injection in adults for the production of subarachnoid block (spinal anesthesia). Chloroprocaine is used for

regional anesthesia 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, i.e. local insensitivity to pain, although other local senses may be affected as well. It all ...

including

spinal anesthesia 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 with or without an opioi ...

, caudal anesthesia and epidural anesthesia. It is also indicated for

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

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 c ...

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 t ...

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 nerves, cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which ...

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 Sense, sensation from the maxilla, nasal cavity, Sinus (anatomy ...

block for dental anesthesia, 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 arises in the pterygopalatine fossa. It passes through the inferior orbital fissure to enter the orbit. It travels through the orbit, ...

block,

ulnar nerve The ulnar nerve is a nerve that runs near the ulna, one of the two long bones in the forearm. 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 ...

block, paravertebral block, intercostal nerve block, sciatic nerve block, stellate ganglion block,

lumbar In tetrapod anatomy, lumbar is an adjective that means of or pertaining to the abdominal segment of the torso, between the diaphragm (anatomy), diaphragm and the sacrum. Naming and location The lumbar region is sometimes referred to as the lowe ...

sympathetic block and interdigital block. It is also used for obstetric anesthesia including pudendal nerve block and paracervical block. Chloroprocaine (Iheezo) is 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 anesthesia in surgical procedures less than 60 minutes' duration using 30–40 mg chloroprocaine. The results showed good surgical anesthesia, a fast onset time, and postoperative mobilization after 90 minutes without complications. The use of chloroprocaine in the

subarachnoid In anatomy, the meninges (; meninx ; ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid sp ...

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 bisulfite Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO3. Sodium bisulfite is not a real compound, but a mixture of salts that dissolve in water to give solutions compose ...

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

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 and ventricular fibrillation. When used for local anae ...

and

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

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

placenta The placenta (: placentas or placentae) 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 ...

, 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 ...

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 is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''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

{{Authority control Local anesthetics 4-Aminobenzoate esters Chlorobenzene derivatives Diethylamino compounds