Benzonatate (Systemic)


VA CLASSIFICATION
Primary: RE302

Commonly used brand name(s): Tessalon.

Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).



Category:


Antitussive. —

Indications

Accepted

Cough (treatment) {16}—Benzonatate is indicated for the symptomatic relief of nonproductive cough. It is used to provide relief of acute cough due to minor throat and bronchial irritation occurring with colds or inhaled irritants. {01} {03} {04} {09} {12} {13} {14} {15}


Pharmacology/Pharmacokinetics

Physicochemical characteristics:
Molecular weight—
    603.7 {16}

Mechanism of action/Effect:

Suppresses cough through a peripheral action, anesthetizing the stretch or cough receptors of vagal afferent fibers, which are located in the respiratory passages, lungs, and pleura; also, may suppress transmission of the cough reflex by a central mechanism, at the level of the medulla. {01} {03} {04} {09} {12}


Other actions:

Local anesthetic activity when applied topically to the mucosa. {03} {04} {09}


Onset of action:

Usually within 15 to 20 minutes. {01} {13}

Duration of action:

Up to 8 hours. {01} {13}

Elimination:
    As with other ester-type local anesthetics (e.g., tetracaine) to which benzonatate is chemically related, excretion may be primarily via metabolism, followed by renal excretion of metabolites. {10}


Precautions to Consider

Cross-sensitivity and/or related problems

Patients sensitive to tetracaine or other ester-type local anesthetics may also be sensitive to benzonatate. {01} {10}

Pregnancy/Reproduction

Pregnancy—
Studies have not been done in humans.

Studies have not been done in animals.

FDA Pregnancy Category C. {01} {13}

Breast-feeding

It is not known whether benzonatate is distributed into breast milk. However, problems in humans have not been documented. {01} {13}

Pediatrics

Appropriate studies have not been performed in children up to 10 years of age. However, benzonatate should not be used in infants and young children since numbness of the mouth, tongue, and pharynx may occur, which may cause swallowing difficulty and aspiration. {03} {07} Children should be instructed not to chew or suck on the capsule before swallowing it since the mouth and throat may become numb from contact with the benzonatate within the capsule and choking may occur. {16}


Geriatrics


No information is available on the relationship of age to the effects of benzonatate in geriatric patients.

Drug interactions and/or related problems
The following drug interactions and/or related problems have been selected on the basis of their potential clinical significance (possible mechanism in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):


Note: Combinations containing any of the following medications, depending on the amount present, may also interact with this medication.

Central nervous system (CNS) depression–producing medications, other (see Appendix II )    (concurrent use may potentiate the CNS depressant effects of these medications or benzonatate {12})


Medications, other    (concurrent use of benzonatate with other medications has resulted rarely in bizarre behavior, including confusion and visual hallucinations {16})


Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).


Risk-benefit should be considered when the following medical problems exist
» Cough, productive    (inhibition of cough reflex may lead to retention of secretions {03} {15})


Sensitivity to benzonatate or topical anesthetics{01}{03}


Side/Adverse Effects
The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:

Those indicating need for medical attention
Incidence rare
    
Confusion{16} —may occur with concurrent use of other medications{16}
    
hypersensitivity reactions, severe, such as bronchospasm{16} (shortness of breath, troubled breathing, tightness in chest, or wheezing), laryngospasm{16} (difficulty in speaking or breathing), or cardiovascular collapse{16} —possibly related to local anesthesia caused by sucking or chewing the capsule rather than swallowing it whole{16}
    
visual hallucinations{16} (seeing things that are not there)—may occur with concurrent use of other medications{16}




Those indicating need for medical attention only if they continue or are bothersome
Incidence less frequent or rare
    
Constipation{01}{03}{04}{09}{13}
    
dizziness, mild{01}{03}{04}{09}{13}
    
drowsiness, mild{01}{03}{04}{09}{13}
    
headache{16}
    
nausea or vomiting{01}{03}{04}{09}{13}
    
pruritus{16} (itching)
    
sensation of burning in the eyes{16}
    
skin rash{01}{03}{04}{09}{13}
    
stuffy nose{01}{03}{04}{09}{13}





Overdose
For more information on the management of overdose or unintentional ingestion, contact a Poison Control Center (see Poison Control Center Listing ).

Clinical effects of overdose
The following effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)–not necessarily inclusive:
Acute and/or chronic
    
CNS stimulation {01}{04}{13}(convulsions; restlessness; trembling)
    
oropharyngeal anesthesia{16} —if capsules are chewed or dissolved in mouth{16}

Note: CNS stimulation may cause tremors and restlessness that may develop into clonic convulsions followed by profound CNS depression. {01} {13} {16}
In some cases, deliberate or accidental overdose has resulted in death. {16}



Treatment of overdose
Specific treatment—Treatment consists of gastric lavage and liberal administration of activated charcoal slurry. Even for conscious patients, protection against aspiration of gastric contents is required because of the possibility of depressed cough and gag reflexes. A short-acting intravenous barbiturate in the smallest effective dose should be used if convulsions are present. Respiratory, cardiovascular, and renal function support are also essential in the treatment of severe intoxication from benzonatate overdosage. CNS stimulants should be avoided. {16}

Supportive care— Patients in whom intentional overdose is confirmed or suspected should be referred for psychiatric consultation.


Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Benzonatate (Systemic) .

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):

Before using this medication
»   Conditions affecting use, especially:
Sensitivity to benzonatate or topical anesthetics





Use in children—Importance of children not chewing or sucking on the capsule before swallowing it; if the medication contained in the capsules comes in contact with the mouth, the mouth and throat may become numb and choking may occur {16}

Other medical problems, especially a productive cough

Proper use of this medication
» Not chewing or sucking on capsules; swallowing whole to avoid local anesthetic effect and choking {01} {03} {13} {16}

» Proper dosing
Missed dose: Taking as soon as possible; not taking if almost time for next dose; not doubling doses

» Proper storage

Precautions while using this medication
Checking with physician if cough persists after medication has been used for 7 days or if high fever, skin rash, or continuing headache is present with cough


Side/adverse effects
Signs of potential side effects, especially confusion, bronchospasm, laryngospasm, cardiovascular collapse, and visual hallucinations


General Dosing Information
It is recommended that the capsules not be chewed or sucked on before they are swallowed. Release of benzonatate from the capsule may produce temporary local anesthesia of the oral mucosa and choking may occur. {01} {03} {09} {13} In addition, severe hypersensitivity reactions have occurred. {16}

For treatment of adverse effects
Severe hypersensitivity reactions, such as bronchospasm, laryngospasm, or cardiovascular collapse, have occurred and may be related to local anesthesia caused by sucking or chewing the capsule rather than swallowing it whole. {16} Severe reactions have required treatment with vasopressor agents and use of supportive measures. {16}


Oral Dosage Forms

BENZONATATE CAPSULES USP

Usual adult and adolescent dose
Antitussive
Oral, 100 mg three times a day, as needed. {01} {13} {15} {16}


Usual adult prescribing limits
600 mg per day. {16}

Usual pediatric dose
Antitussive
Children up to 10 years of age: Dosage has not been established. {16}

Children 10 years of age and older: See Usual adult and adolescent dose . {16}


Usual geriatric dose
See Usual adult and adolescent dose .

Strength(s) usually available
U.S.—


100 mg (Rx) [Tessalon{16}][Generic]

Canada—


100 mg (OTC) [Tessalon]

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a tight, light-resistant container. {11} {13} {16}

Auxiliary labeling:
   • Do not chew or suck on capsule. {01} {16}



Revised: 08/13/1998



References
  1. Tessalon package insert (Forest—US), Rev 1986.
  1. Laverty RF. New cough products call for close counseling. Drug Topics 1983 Nov 21: 30-6.
  1. AMA Drug evaluations. 6th ed. Chicago: American Medical Association, September 1986: 383.
  1. Reynolds JEF, editor. Martindale, the extra pharmacopeia. 29th ed. London: The Pharmaceutical Press, 1989: 906.
  1. Irwin RS, Curley FJ, Pratter MR. The effects of drugs on cough. Eur J Respir Dis Suppl 1987; 153: 173-81.
  1. Weippl G. Therapeutic approaches to the common cold in children. Clin Ther 1984; 6(4): 475-82.
  1. Cohan JA, Manning TJ, Lukash L, et al. Two fatalities resulting from Tessalon. Vet Hum Toxicol 1986; 28(6): 543-4.
  1. Knauer CM, Castell JA, Dalton CB, et al. Pharyngeal/upper esophageal sphincter pressure dynamics in humans. Dig Dis Sci 1990; 35(6): 774-80.
  1. McEvoy GK, editor. AHFS Drug information 90. Bethesda, MD: American Society of Hospital Pharmacists, 1990: 1508.
  1. Anesthetics (Mucosal-Local) monograph, USP DI 1990.
  1. The United States pharmacopeia. The national formulary. USP 22nd revision (January 1, 1990). NF 17th ed (January 1, 1990). Rockville, MD: The United States Pharmacopeial Convention, Inc.; 1990.
  1. Reviewers' responses to monograph revision of 12/90.
  1. Tessalon package insert (Forest—US), Rev 8/88.
  1. Irwin RS, Curley FJ, Bennett FM. Appropriate use of antitussives and protussives. Drugs 1993; 46(1): 80-91.
  1. Tessalon insert (Ciba-Geigy—Canada). In Krogh CME, editor. CPS Compendium of pharmaceuticals and specialties. 26th ed. Ottawa: Canadian Pharmaceutical Association; 1991. p. 1198.
  1. Tessalon (Forest). In: PDR Physicians' desk reference. 52nd ed. 1998. Montvale, NJ: Medical Economics Company; 1998. p. 955-6.
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