Benzonatate

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Benzonatate
Benzonatate.svg
Clinical data
Trade names Tessalon, Tessalon Perles
AHFS/Drugs.com Monograph
MedlinePlus a682640
Pregnancy
category
  • US: C (Risk not ruled out)
Routes of
administration
Oral
ATC code
Pharmacokinetic data
Elimination half-life 3-8 hours
Identifiers
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
ECHA InfoCard 100.002.904 Edit this at Wikidata
Chemical and physical data
Formula C30H53NO11
Molar mass 603.742 g/mol
3D model (JSmol)
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Benzonatate—marketed under the trade names Tessalon, Tessalon Perles, and Zonatuss—is a non-narcotic oral cough suppressant, or antitussive, with effects that last from six to eight hours. Since it is not an opioid, benzonatate has no abuse liability, in contrast to some other cough medications such as codeine. Benzonatate was approved by the U.S. Food and Drug Administration (FDA) in 1958.[1]

Chemical structure[edit]

Benzonatate is a butylamine, chemically related to other ester local anesthetics such as procaine and tetracaine.[citation needed]

Pharmacologic mechanisms of action[edit]

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.[2]

Indications[edit]

An antitussive, benzonatate is employed to reduce coughing in various respiratory conditions such as bronchitis, emphysema, influenza, and pneumonia.[2]

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.[3]

Dosage and administration[edit]

100mg generic Benzonatate capsules
100mg generic benzonatate capsules

Benzonatate is sold as yellow or blue 100 mg and 200 mg softgel capsules. Initial dose is one 100 mg perle (gelcap) by mouth, 3 times a day. Dosage may be increased as necessary, up to a maximum of 600 mg per day.[1]

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

Adverse reactions[edit]

Reported side effects include drowsiness, dizziness, and dysphagia. There are reports of death related to overdose of benzonatate, mostly in children.[4]

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.[5]

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,[citation needed] followed in extreme cases by convulsions and death.[6]

References[edit]

  1. ^ a b MedicineNet.com: Benzonatate
  2. ^ a b Medicalook.com: Benzonatate
  3. ^ Medline Plus: Benzonatate
  4. ^ "Benzonatate".
  5. ^ Crouch, B. I.; Knick, K. A.; Crouch, D. J.; Matsumura, K. S.; Rollins, D. E. (1998). "Benzonatate overdose associated with seizures and arrhythmias". Journal of Toxicology. Clinical Toxicology. 36 (7): 713–718. doi:10.3109/15563659809162620. PMID 9865240.
  6. ^ Cohan, J. A.; Manning, T. J.; Lukash, L.; Long, C.; Ziminski, K. R.; Conradi, S. E. (1986). "Two fatalities resulting from Tessalon (benzonatate)". Veterinary and human toxicology. 28 (6): 543–544. PMID 3788039.