benzocaine

アミノ安息香酸エチル。ベンゾカイン 　

WordNet

1. a white crystalline ester used as a local anesthetic (同)ethyl_aminobenzoate

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/12/13 22:19:44」(JST)

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Benzocaine

Systematic (IUPAC) name
Ethyl 4-aminobenzoate
Clinical data
Trade names	Anbesol, Cepacol, Lanacane, Orajel
AHFS/Drugs.com	monograph
Pregnancy category	US: C (Risk not ruled out)
Legal status	UK: General sales list (GSL, OTC) US: OTC
Routes of administration	Topical
Identifiers
CAS Number	94-09-7 Y
ATC code	C05AD03 D04AB04, QN01AX92, N01BA05, R02AD01
PubChem	CID: 2337
DrugBank	DB01086 Y
ChemSpider	13854242 Y
UNII	U3RSY48JW5 Y
KEGG	D00552 Y
ChEBI	CHEBI:116735 Y
ChEMBL	CHEMBL278172 Y
Chemical data
Formula	C9H11NO2
Molecular mass	165.189 g/mol
SMILES O=C(OCC)c1ccc(N)cc1
InChI InChI=1S/C9H11NO2/c1-2-12-9(11)7-3-5-8(10)6-4-7/h3-6H,2,10H2,1H3 Y Key:BLFLLBZGZJTVJG-UHFFFAOYSA-N Y
Y (what is this?)  (verify)

Benzocaine is a local anesthetic commonly used as a topical pain reliever or in cough drops. It is the active ingredient in many over-the-counter anesthetic ointments such as products for oral ulcers. It is also combined with antipyrine to form A/B otic drops to relieve ear pain and remove earwax.

Chemical properties

Benzocaine is the ethyl ester of p-aminobenzoic acid (PABA). It can be prepared from PABA and ethanol by Fischer esterification or via the reduction of ethyl p-nitrobenzoate. Benzocaine is sparingly soluble in water; it is more soluble in dilute acids and very soluble in ethanol, chloroform and ethyl ether. The melting point of benzocaine is 88–90 °C, and the boiling point is about 310 °C. The density of benzocaine is 1.17 g/cm³.

History

Benzocaine was first synthesized in 1890 by the German chemist Eduard Ritsert (1859–1946), in the town of Eberbach and introduced to the market in 1902 under the name "Anästhesin".

Mechanism of action

Pain is caused by the stimulation of free nerve endings. When the nerve endings are stimulated, sodium enters the neuron, causing depolarization of the nerve and subsequent initiation of an action potential. The action potential is propagated down the nerve toward the central nervous system, which interprets this as pain. Benzocaine acts to inhibit the voltage-dependent sodium channels (VDSCs) on the neuron membrane, stopping the propagation of the action potential.

Uses

Benzocaine is indicated to treat a variety of pain-related conditions. It may be used for:

• Local anesthesia of oral and pharyngeal mucous membranes (sore throat, cold sores, mouth ulcers, toothache, sore gums, denture irritation)
• Otic Pain (earache)
• Surgical or procedural local anesthesia

Formulations

Benzocaine can come in a variety of preparations including:
Oral preparations:

• Lozenges (ex. Cepacol, Mycinettes)

Topical preparations:

• Aerosol (ex. Topex)
• Gel (ex. Orajel)
• Paste (ex. Orabase)

Otic preparations:

• Solution (ex. Allergen)

Side effects

Benzocaine is generally well-tolerated and non-toxic when applied topically as recommended.

However, there have been reports of serious, life-threatening adverse effects (e.g., seizures, coma, irregular heart beat, respiratory depression) with over-application of topical products or when applying topical products that contain high concentrations of benzocaine to the skin.

Over-application of oral anesthetics such as benzocaine can increase the risk of pulmonary aspiration by relaxing the gag-reflex and allowing regurgitated stomach contents or oral secretions to enter the airway. Applying an oral anesthetic and consuming beverages before going to bed can be particularly hazardous.

The topical use of higher concentration (14-20%) benzocaine spray products applied to the mouth or mucous membranes has been found to be a cause of methemoglobinemia, a disorder in which the amount of oxygen carried by the blood is greatly reduced. This side effect is most common in children under 2 years of age. As a result, the FDA has stated that benzocaine products should not be used in children under 2 years of age, unless directed by and supervised by a healthcare professional. Symptoms of methemoglobinemia usually occur minutes to hours of applying benzocaine, and can occur upon the first-time use or after additional use.

Benzocaine may cause allergic reactions. These include:

• Contact dermatitis (redness and itchiness)
• Anaphylaxis (rare)

Other uses

Jiffy Toothache Drops bottle (7.75% Benzocaine)

Benzocaine is used as a key ingredient in numerous pharmaceuticals:

• Some glycerol-based ear medications for use in removing excess wax as well as relieving ear conditions such as otitis media and swimmers ear.
• Some previous diet products such as Ayds.
• Some condoms designed to prevent premature ejaculation. Benzocaine largely inhibits sensitivity on the penis, and can allow for an erection to be maintained longer (in a continuous act) by delaying ejaculation. Conversely, an erection will also fade faster if stimulus is interrupted.
• Benzocaine mucoadhesive patches have been used in reducing orthodontic pain.
• In Poland it is included, together with menthol and zinc oxide, in the liquid powder (not to be confused with the liquid face powder) used mainly after mosquito stings. Today's ready made Pudroderm was once used there as pharmaceutical compound.

Benzocaine is commonly found, particularly in Britain, as an impurity in street cocaine. Whilst giving a numbing effect similar to cocaine on users' gums it does not actually produce the effects of cocaine. But Also benzocaine can and has been mistaken for a false positive for cocaine.

Synthesis

Prepd by the esterification of p-aminobenzoic acid: by the reduction of ethyl p-nitrobenzoate:

Benzocaine can be prepared by esterfication using 4-aminobenzoic acid and ethanol. It can also be prepared by reduction of ethyl 4-nitrobenzoate to the amine.

In industrial practice, the reducing agent is usually iron and water in the presence of a little acid.

References

External links

• Public Health Advisory: Benzocaine Sprays by the Food and Drug Administration.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 小児における局所麻酔剤 topical anesthetics in children
• 2. Symptomatic treatment of acute pharyngitis in adults
• 3. メトヘモグロビン血症の臨床的特徴、診断、および治療 clinical features diagnosis and treatment of methemoglobinemia
• 4. 小児および思春期における咽頭痛：対症療法 sore throat in children and adolescents symptomatic treatment
• 5. Hemolytic anemia due to drugs and toxins

English Journal

• Homology modeling of Kv1.5 channel block by cationic and electroneutral ligands.

• Tikhonov DB1, Zhorov BS2.Author information 1Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia. Electronic address: denistikhonov2002@yahoo.com.2Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia; Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.AbstractThe inner pore of potassium channels is targeted by many ligands of intriguingly different chemical structures. Previous studies revealed common and diverse characteristics of action of ligands including cooperativity of ligand binding, voltage- and use-dependencies, and patterns of ligand-sensing residues. Not all these data are rationalized in published models of ligand-channel complexes. Here we have used energy calculations with experimentally defined constraints to dock flecainide, ICAGEN-4, benzocaine, vernakalant, and AVE0118 into the inner pore of Kv1.5 channel. We arrived at ligand-binding models that suggest possible explanations for different values of the Hill coefficient, different voltage dependencies of ligands action, and effects of mutations of residues in subunit interfaces. Two concepts were crucial to build the models. First, the inner-pore block of a potassium channel requires a cationic "blocking particle". A ligand, which lacks a positively charged group, blocks the channel in a complex with a permeant ion. Second, hydrophobic moieties of a flexible ligand have a tendency to bind in hydrophobic subunit interfaces.
• Biochimica et biophysica acta.Biochim Biophys Acta.2014 Mar;1838(3):978-87. doi: 10.1016/j.bbamem.2013.11.019. Epub 2013 Dec 5.
• The inner pore of potassium channels is targeted by many ligands of intriguingly different chemical structures. Previous studies revealed common and diverse characteristics of action of ligands including cooperativity of ligand binding, voltage- and use-dependencies, and patterns of ligand-sensing r
• PMID 24316168

• Potential diversion of local anesthetics from dental offices for use as cocaine adulterants.

• Saraghi M1, Hersh EV.Author information 1Dr. Saraghi was an instructor of dental anesthesiology, Department of Periodontics, Division of Pediatric Dentistry, and Department of Oral Surgery and Pharmacology, School of Dental Medicine, University of Pennsylvania, Philadelphia, when this article was written. She now is a dentist anesthesiologist, Northwest Dental Anesthesia, 5528 E. Green Lake Way N., #19, Seattle, Wash. 98103, msaraghi@gmail.com.AbstractBACKGROUND: /st> Reports of lidocaine and benzocaine in the bloodstreams of people who abuse cocaine with accompanying reports of seizures and methemoglobinemia indicate that there is a potential that local anesthetics are being diverted from dental offices and being used as cocaine adulterants. These adulterants augment the nasal numbness produced by inhaling cocaine.
• Journal of the American Dental Association (1939).J Am Dent Assoc.2014 Mar;145(3):256-9. doi: 10.14219/jada.2013.33.
• BACKGROUND: /st> Reports of lidocaine and benzocaine in the bloodstreams of people who abuse cocaine with accompanying reports of seizures and methemoglobinemia indicate that there is a potential that local anesthetics are being diverted from dental offices and being used as cocaine adulterants.
• PMID 24583890

• Anesthetic efficacy of Oraqix® versus Hurricaine® and placebo for pain control during non-surgical periodontal treatment.

• Mayor-Subirana G1, Yagüe-García J, Valmaseda-Castellón E, Arnabat-Domínguez J, Berini-Aytés L, Gay-Escoda C.Author information 1Facultat d'Odontologia (UB), Campus de Bellvitge, Pavelló de Govern, Feixa Llarga, s/n, 08907 L'Hospitalet de Llobregat, eduardvalmaseda@ub.edu.AbstractObjectives: To evaluate the efficacy of Oraqix® during scaling and root planing (SRP) in comparison with 20% benzocaine and placebo. Study Design: 15 patients requiring 4 sessions of SRP were enrolled. For each patient, Oraqix®, Hurricaine®, vaseline or no anesthetic product were randomly assigned each to a quadrant. Treatment pain was evaluated on a 100 mm Visual Analog Scale (VAS) and on a Verbal Rating Scale (VRS). The amount of product administered, the need to re-anesthetise, patient and operator satisfaction and the onset of side-effects were also recorded. Results: Oraqix® was significantly better than nothing, with a reduction of VAS score to 13.3 units, but without significant differences with Vaseline or Hurricaine®. Oraqix® was better in VRS reduction than not using any anesthetic (p=0.001) or using vaseline (p=0.024), but similar to Hurricaine® (p=0.232). Conclusions: Oraqix® effectively controls pain in SRP procedures, with few side-effects and a good acceptance on the part of patients and clinicians.
• Medicina oral, patología oral y cirugía bucal.Med Oral Patol Oral Cir Bucal.2014 Mar 1;19(2):e192-201.
• Objectives: To evaluate the efficacy of Oraqix® during scaling and root planing (SRP) in comparison with 20% benzocaine and placebo. Study Design: 15 patients requiring 4 sessions of SRP were enrolled. For each patient, Oraqix®, Hurricaine®, vaseline or no anesthetic product were randomly assigne
• PMID 24316699

Japanese Journal

• Pain Perception and Anaesthesia in Research Frogs

• Experimental animals 62(2), 87-92, 2013-04-01
• NAID 10031163547

• 症例 表面局所麻酔剤ハリケーンゲルの使用によって生じたと考えられるメトヘモグロビン血症の1例

• 形成外科 50(10), 1201-1205, 2007-10
• NAID 40015673658

• アフリカツメガエル卵母細胞に発現したセロトニントランスポーターに対する麻酔薬の作用

• 四国歯学会雑誌 19(1), 117-129, 2006-06
• NAID 110006560979

Related Links

• Benzocaineとは - goo Wikipedia (ウィキペディア)

Benzocaine is used as a key ingredient in numerous pharmaceuticals: Some glycerol-based ear medications for use in removing excess wax as well as relieving ear conditions such as otitis media and swimmers ear. Some previous ...

• Benzocaine topical medical facts from Drugs.com

Benzocaine is a local anesthetic (numbing medication). It works by blocking nerve signals in your body. Benzocaine topical is used to reduce pain or discomfort caused by minor skin irritations, sore throat, sunburn ...

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リンク元	「アミノ安息香酸エチル」

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英

ethylaminobenzoate

ラ

ethylis aminobenzoas

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ベンゾカイン benzocaine、パラアミノ安息香酸エチル ethyl p-aminobenzoate

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アネスタミン anestamine、ベンゾカイン benzocaine、ジンジカイン、スルカイン、ニチカイン、ネオザロカインパスタ 、ハリケイン、ヒノポロン、ビーゾカイン、プロネスパスタ、ヘルミチンS