Benzonatate

Benzonatate

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Systematic (IUPAC) name
2-[2-[2-[2-[2-[2-[2-[2- (2-methoxyethoxy) ethoxy] ethoxy] ethoxy] ethoxy] ethoxy] ethoxy] ethoxy] ethyl4-butylaminobenzoate
Clinical data
Pregnancy category	US: C (Risk not ruled out)
Pharmacokinetic data
Biological half-life	3-8 hours
Identifiers
CAS Number	104-31-4
ATC code	R05DB01 (WHO)
PubChem	CID 7699
DrugBank	APRD00629
Chemical data
Formula	C30H53NO11
Molar mass	603.742 g/mol[[]]
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Benzonatate or 2,5,8,11,14,17,20,23,26-nonaoxaoctacosan-28-yl para-butylaminobenzoate is a non-narcotic oral antitussive (cough suppressant) with effects that last from 6 to 8 hours. Being non-narcotic, benzonatate is not prone to abuse like some other cough medications such as codeine or dextromethorphan. Benzonatate was approved by the FDA in 1958.

Chemical structure

Benzonatate is a butylamine, chemically related to other ester local anesthetics such as procaine and tetracaine. Benzonatate is unrelated to codeine, dextromethorphan, and other opioids that are frequently used to suppress coughs. Benzonatate has the following structural formula:

Pharmacologic mechanisms of action

Benzonatate is thought to act as a local anesthetic, decreasing the sensitivity of stretch receptors in the lower airway and lung, thereby reducing the drive to cough after taking a deep breath.

Indications

A potent antitussive, benzonatate is employed to reduce coughing in various respiratory conditions such as asthma, bronchitis, emphysema, influenza, and pneumonia.

It has been used in small doses as a topical anesthetic for mouth or pharyngeal pain. This practice is not recommended, because the oropharyngeal anesthesia may result in pulmonary aspiration.

Dosage and administration

Benzonatate is sold as yellow or blue 100mg and 200mg softgel capsules. Initial dose is one 100mg perle (gelcap) by mouth, 3 times a day. Dosage may be increased as necessary, up to a maximum of 600mg per day.

Due to its potency and potential toxicity, the capsules must be swallowed intact in order to allow slower release of the medication.

Adverse reactions

Reported side effects include drowsiness and dizziness and dysphagia.

Para-aminobenzoic acid (PABA) is a metabolite of the ester class of local anesthetics, which includes benzonatate, as well as procaine and tetracaine. Severe allergic reactions have been reported in patients who are allergic to PABA. Severe sensitivity reactions to benzonatate have resulted in respiratory side effects such as bronchospasm, laryngospasm and cardiac arrest.

Excessive absorption of benzonatate (a local anesthetic) in the oral mucosa will result in the rapid development of numbness of the mouth and throat. In extreme cases, the mouth and pharynx may become so numb that pulmonary aspiration may occur.

Excessive absorption of benzonatate will occur if the gelcaps are chewed or allowed to dissolve in the mouth. This may lead to an overdose of the drug. Overdose of benzonatate may manifest as central nervous system side effects, such as mental confusion and hallucination, restlessness and tremors, followed in extreme cases by convulsions and death.

Brand names

It is sold in the USA generically or under the brand name Tessalon Perles (gelcaps) or Tessalon Capsules. It is sold in other countries under various brand names, including Benzonatato, Benzonatatum, Benzononantin, Benzononatine, Exangit, Tesalon, Tessalin, and Ventussin.

References

pl:Benzonatat pt:Benzonatato