Benzonatate (Tessalon Perles) Contraindications
Benzonatate is contraindicated in patients at high risk of aspiration, and should be used with extreme caution or avoided entirely in frail individuals with serious illnesses, as its local anesthetic effect can cause oropharyngeal anesthesia that impairs protective airway reflexes. 1
Primary Contraindication: Aspiration Risk
Patients with impaired swallowing or airway protection should not receive benzonatate because it acts as a local anesthetic on the oropharynx, which can eliminate protective cough and gag reflexes, dramatically increasing aspiration risk. 1
This is particularly critical in frail cancer patients, elderly individuals, or those with neurological conditions affecting swallowing. 1
The first dose must be administered in an inpatient setting to monitor for reflex bronchospasm, and patients must avoid food and drink for at least one hour after each dose. 1
Relative Contraindications
Pregnancy and Lactation
- Benzonatate should be used with caution in pregnant or breastfeeding individuals due to limited safety data, requiring individualized risk-benefit assessment. 1
Drug Interactions
- While not explicitly stated as contraindications in the provided evidence, benzonatate shares structural similarity with local anesthetics like tetracaine and procaine, suggesting caution with other medications affecting cardiac conduction or sodium channels. 2
Clinical Context for Use
Benzonatate is reserved for opioid-resistant cough that has failed to respond to peripheral antitussives, not as first-line therapy. 3, 1
The typical dosing is 100-200 mg up to four times daily. 3, 1
Severe toxicity can occur rapidly with overdose, including seizures, cardiac arrest, dysrhythmias, and death, particularly with intentional ingestions. 4, 5, 6
Important Safety Considerations
Benzonatate inhibits voltage-gated sodium channels (including Nav1.7) similar to local anesthetics, which explains both its therapeutic effect and toxicity profile. 2
Serious adverse effects occurred in 22% of intentional overdoses but were rare (0.7%) in unintentional exposures in one poison center review. 6
Deaths have been reported even in young patients, with cardiac arrest occurring within 1-2 hours of ingestion. 4, 5