Are Tessalon Perles (benzonatate) contraindicated in the elderly?

Tessalon Perles (Benzonatate) Use in the Elderly

Tessalon Perles (benzonatate) is not contraindicated in the elderly, but it requires cautious use with careful patient selection and education due to significant safety concerns, particularly the risk of severe toxicity from accidental overdose or misuse.

Key Safety Considerations

Toxicity Profile

• Benzonatate can cause rapid-onset life-threatening adverse events including cardiac arrest, seizures, and severe neurological complications even with relatively small overdoses 1
• Fatal cases have been documented with ingestion of as few as 10 capsules (2000 mg), with death occurring within 1 hour of ingestion 2, 1
• The drug is structurally similar to local anesthetics (tetracaine, procaine) and shares their potential for serious toxicity 1

Age-Related Vulnerabilities in the Elderly

• Altered pharmacokinetics: Elderly patients have reduced water content and increased fat content, affecting drug distribution; they should be treated as renally insufficient patients even with normal serum creatinine 3
• Diminished homeostatic mechanisms: The elderly experience stronger drug effects with higher rates of adverse events due to progressive decline in counterregulatory mechanisms 3
• Increased CNS sensitivity: The aging brain is especially sensitive to drug effects, with increased risk of confusion, delirium, and impaired motor coordination 3
• Polypharmacy risks: Elderly patients often take multiple medications, increasing the risk of drug interactions and adverse drug events 4

Clinical Recommendations

Patient Selection Criteria

• Cognitive assessment required: Avoid benzonatate in patients with cognitive impairment who may not understand proper administration instructions 4
• Evaluate swallowing ability: The capsules must be swallowed whole; patients who cannot reliably do this should not receive benzonatate 1
• Screen for depression/suicidal ideation: Given the rapid lethality in overdose, careful psychiatric screening is essential 1

Prescribing Precautions

• Limit quantity prescribed: Dispense the smallest effective quantity to minimize overdose risk 1
• Explicit patient education: Emphasize that capsules must never be chewed, crushed, or dissolved in the mouth due to risk of severe local anesthetic effects and systemic toxicity 1
• Consider safer alternatives first: Given the limited treatment options in overdose and rapid onset of life-threatening complications, evaluate whether safer antitussive options are appropriate 1

Monitoring Requirements

• Assess for signs of CNS depression, confusion, or coordination impairment, which may be more pronounced in elderly patients 3
• Evaluate renal function before prescribing, as drug excretion declines with age 3

Common Pitfalls to Avoid

• Do not assume normal cognition: Even seemingly intact elderly patients may have subtle cognitive deficits that impair medication safety 4
• Do not prescribe without explicit counseling: The rapid lethality of benzonatate overdose demands thorough patient and caregiver education 1
• Do not overlook polypharmacy: Review all concurrent medications for potential interactions and cumulative CNS effects 4