Drug class
Non-narcotic oral antitussive agent" that "acts peripherally by anesthetizing the stretch receptors located in the respiratory passages, lungs, and pleura," reducing the cough reflex at its source rather than acting centrally; onset is "within 15 to 20 minutes" with effect lasting "3 to 8 hours.
Uses
"Benzonatate capsules is indicated for the symptomatic relief of cough" in patients over age 10.
Boxed warning
BOXED WARNING Hypersensitivity Severe hypersensitivity reactions (including bronchospasm, laryngospasm and cardiovascular collapse) have been reported which are possibly related to local anesthesia from sucking or chewing the capsule instead of swallowing it. Severe reactions have required intervention with vasopressor agents and supportive measures. Psychiatric Effects Isolated instances of bizarre behavior, including mental confusion and visual hallucinations, have also been reported in patients taking benzonatate in combination with other prescribed drugs. Accidental Ingestion and Death in Children Keep benzonatate out of reach of children. Accidental ingestion of benzonatate resulting in death has been reported in children below age 10. Signs and symptoms of overdose have been reported within 15 to 20 minutes and death has been reported within one hour of ingestion. If accidental ingestion occurs, seek medical attention immediately (see OVERDOSAGE ).
Warnings
No boxed warning, but the label carries a prominent warning regarding accidental ingestion. Contraindicated in patients with "hypersensitivity to benzonatate or related compounds," including possible cross-sensitivity to local anesthetics such as tetracaine. Major warnings: capsules must be swallowed whole, never chewed, dissolved, or sucked, because "severe hypersensitivity reactions (including bronchospasm, laryngospasm and cardiovascular collapse)" and rapid oropharyngeal anesthesia/choking can occur if the capsule ruptures in the mouth; "accidental ingestion of benzonatate capsules resulting in death has been reported in children below age 10," so it must be kept out of children's reach; isolated reports of "bizarre behavior, including mental confusion and visual hallucinations" when combined with other drugs.
Contraindications
CONTRAINDICATIONS Hypersensitivity to benzonatate or related compounds.
Overdose
OVERDOSAGE Intentional and unintentional overdose may result in death, particularly in children. The drug is chemically related to tetracaine and other topical anesthetics and shares various aspects of their pharmacology and toxicology. Drugs of this type are generally well absorbed after ingestion. Signs and Symptoms The signs and symptoms of overdose of benzonatate capsules have been reported within 15-20 minutes. If capsules are chewed or dissolved in the mouth, oropharyngeal anesthesia will develop rapidly, which may cause choking and airway compromise. CNS stimulation may cause restlessness and tremors which may proceed to clonic convulsions followed by profound CNS depression. Convulsions, coma, cerebral edema and cardiac arrest leading to death have been reported within 1 hour of ingestion. Treatment In case of overdose, seek medical attention immediately. Evacuate gastric contents and administer copious amounts of activated charcoal slurry. Even in the conscious patient, cough and gag reflexes may be so depressed as to necessitate special attention to protection against aspiration of gastric contents and orally administered materials. Convulsions should be treated with a short-acting barbiturate given intravenously and carefully titrated for the smallest effective dosage. Intensive support of respiration and cardiovascular-renal function is an essential feature of the treatment of severe intoxication from overdosage. Do not use CNS stimulants.
Dosage & administration
DOSAGE AND ADMINISTRATION Adults and Children over 10 years of age: Usual dose is one 100 mg or 200 mg capsule three times a day as needed for cough. If necessary to control cough, up to 600 mg daily in three divided doses may be given. Benzonatate capsules should be swallowed whole. Benzonatate capsules are not to be broken, chewed, dissolved, cut or crushed.
Side effects
Reported reactions include CNS effects such as "sedation; headache; dizziness; mental confusion; visual hallucinations," gastrointestinal effects ("constipation; nausea; GI upset"), and other effects including "nasal congestion; numbness of the chest; pruritus; skin eruptions."
