Chloroprocaine

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Chloroprocaine
Chloroprocaine.svg
Systematic (IUPAC) name
2-diethylaminoethyl-4-amino-2-chloro-benzoate
Clinical data
AHFS/Drugs.com Micromedex Detailed Consumer Information
Legal status
?
Identifiers
CAS number 133-16-4 YesY
ATC code N01BA04
PubChem CID 8612
DrugBank DB01161
ChemSpider 8293 YesY
UNII 5YVB0POT2H YesY
KEGG D07678 YesY
ChEBI CHEBI:3636 YesY
ChEMBL CHEMBL1179047 N
Chemical data
Formula C13H19ClN2O2 
Mol. mass 270.755 g/mol
 N (what is this?)  (verify)

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 vasoconstrics. Chloroprocaine is an ester anesthetic.[1]

Sub-arachnoid block or SAB[edit]

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 without TNS.

These data are based upon a retrospective review of 672 patients suitable for spinal anaesthesia in surgical procedures of less than 60 minutes duration using 30–40 mg chloroprocaine. The results showed good surgical anaesthesia, a fast onset time and post-operative mobilization after 90 minutes without complications.[2]

The use of chloroprocaine in the subarachnoid space has been questioned.[3] In the early 1980s, there were several case reports of neurological deficits after inadvertent intrathecal injections intended for epidural delivery.[4] These doses were an order of magnitude higher than is currently used for intrathecal delivery.[5][6][7] It is also thought that these deficits were also related to the preservative sodium bisulfate,[8][9] although this is also controversial.[10][11]

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.[12][13]

It is currently not FDA approved [14] in the United States for intrathecal use but is approved in Europe.[15]

Obstetrics[edit]

Amide-linked local anesthetic agents, such as lidocaine and bupivacaine, can become "trapped" in their ionized forms on the fetal side of the placenta, and therefore their net transfer across the placenta is increased. An ester-linked local anesthetic agent, 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 analgesia and a decompensating fetus, because it does not participate in ion trapping. Placental transfer of 2-chloroprocaine is not influenced by fetal acidosis.[16]

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.[17][18]

It is not used in intravenous regional anesthesia due to the risk of thrombophlebitis.[citation needed]

Chemistry[edit]

Synthesis of this drug is accomplished by directly reacting the hydrochloride salt of 4-amino-2-chlorobenzoyl chloride with the hydrochloride salt of 2-diethylaminoethanol. The hydrochloride salt of 4-amino-2-chlorobenzoyl chloride is synthesized by reacting 2-chloro-4-aminobenzoic acid with thionyl chloride.

Chloroprocaine synthesis: H.C. Marks, H.I. Rubin, U.S. Patent 2,460,139 (1949).

See also[edit]

References[edit]

  1. ^ Drug bank entry for Chloroprocaine
  2. ^ Ampres (chloroprocaine) Summary of Product Characteristics, Palas T, Cloroprocaina in chirurgia ambulatoriale: uno studio osservazionale, Perimed 2009, 3(2):31-34
  3. ^ Drasner K. Chloroprocaine spinal anesthesia: back to the future? Anes analg 2005; 100: 549-52.
  4. ^ Reisner, Laurence S., Bruce N. Hochman, and Michael H. Plumer. "Persistent neurologic deficit and adhesive arachnoiditis following intrathecal 2-chloroprocaine injection." Anesthesia & Analgesia 59.6 (1980): 452-454
  5. ^ Förster, J. G., et al. "Chloroprocaine vs. articaine as spinal anaesthetics for day‐case knee arthroscopy." Acta Anaesthesiologica Scandinavica 55.3 (2011): 273-281.
  6. ^ Förster, J. G., et al. "Chloroprocaine 40 mg produces shorter spinal block than articaine 40 mg in day‐case knee arthroscopy patients." Acta Anaesthesiologica Scandinavica (2013).
  7. ^ Lacasse, Marie-Andrée, et al. "Comparison of bupivacaine and 2-chloroprocaine for spinal anesthesia for outpatient surgery: a double-blind randomized trial." Canadian Journal of Anesthesia/Journal canadien d'anesthésie 58.4 (2011): 384-391.
  8. ^ Gissen, Aaron J., Sanjay Datta, and Donald Lambert. "The Chloroprocaine Controversy: II. Is Chloroprocaine Neurotoxic?." Regional Anesthesia and Pain Medicine 9.3 (1984): 135-145.
  9. ^ Wang, B. C., et al. "Lumbar Subarachnoid Ethylenediaminetetraacetate Induces Hindlimb Tetanic Contractions in Rats Prevention by CaCl2 Pretreatment; Observation of Spinal Nerve Root Degeneration." Anesthesia & Analgesia 75.6 (1992): 895-899.
  10. ^ Taniguchi, Masahiko, Andrew W. Bollen, and Kenneth Drasner. "Sodium bisulfite: scapegoat for chloroprocaine neurotoxicity?." Anesthesiology 100.1 (2004): 85-91.
  11. ^ Cabré, Francesc, et al. "Occurrence and comparison of sulfite oxidase activity in mammalian tissues." Biochemical medicine and metabolic biology 43.2 (1990): 159-162.
  12. ^ Goldblum, E., and A. Atchabahian. "The use of 2‐chloroprocaine for spinal anaesthesia." Acta Anaesthesiologica Scandinavica (2013).
  13. ^ Förster, J. G., et al. "Chloroprocaine 40 mg produces shorter spinal block than articaine 40 mg in day‐case knee arthroscopy patients." Acta Anaesthesiologica Scandinavica (2013).
  14. ^ Pollock, Julia E. "Intrathecal Chloroprocaine—Not yet “Safe” by US FDA Parameters." International Anesthesiology Clinics 50.1 (2012): 93-100.
  15. ^ http://www.anesthesiologynews.com/ViewArticle.aspx?d=Clinical+Anesthesiology&d_id=1&i=June+2013&i_id=962&a_id=23319
  16. ^ Philipson EH, Kuhnert BR, Syracuse CD. Fetal acidosis, 2-chloroprocaine, and epidural anesthesia for cesarean section. Am J Obstet Gynecol. 1985 Feb 1;151(3):322-4.
  17. ^ Chestnut: Obstetric Anesthesia, 3rd ed, p333.
  18. ^ Hughes: Anesthesia for Obstetrics, 4th ed, p75.