Can a 69-year-old woman with dementia, COVID-19, influenza, streptococcal pharyngitis, who is taking amlodipine, atorvastatin, an angiotensin-converting enzyme inhibitor (donzepril), levothyroxine, lorazepam, and prescribed antivirals/antibiotics safely take benzonatate for cough?

Can This Patient Take Benzonatate?

Yes, benzonatate can be used cautiously in this 69-year-old woman with dementia, COVID-19, influenza, and streptococcal pharyngitis for symptomatic cough relief, but it is not the preferred first-line option given her complex medical situation and dementia.

Preferred Cough Management Approach

First-Line Recommendations for COVID-19 Related Cough

• Codeine-based antitussives are preferred for distressing cough in COVID-19 patients, including codeine linctus, codeine phosphate tablets, or morphine sulfate oral solution 1
• These centrally acting cough suppressants have better evidence for efficacy and safety in acute respiratory infections 1
• Non-pharmacological approaches should be attempted first, including controlled breathing techniques, pursed-lip breathing, and positioning strategies 1

Why Benzonatate is Not First-Line

• While benzonatate has demonstrated effectiveness in controlling cough (80% efficacy in one case series), the evidence is primarily from cancer-related cough, not acute respiratory infections 1
• Benzonatate poses significant safety concerns in overdose, particularly risk of seizures, cardiac dysrhythmias, and death due to its sodium channel blocking properties similar to local anesthetics 2, 3
• In patients with dementia, medication management is already compromised, increasing risk of accidental overdose 4, 5

Critical Safety Considerations if Benzonatate is Used

Dementia-Specific Risks

• Patients with dementia have substantially elevated rates of polypharmacy (91.7% taking ≥4 medications) and medication errors 5
• The COVID-19 pandemic has further constrained access to monitoring services for dementia patients, potentially worsening medication-related issues 5, 6
• Benzonatate capsules must be swallowed whole and never chewed or dissolved, as this can cause rapid release and severe toxicity—a critical concern in patients with dementia who may have difficulty following instructions 2, 3

Overdose Risk Profile

• Intentional exposures to benzonatate resulted in serious adverse effects in 22% of cases, including seizures, ECG changes, CNS depression, and death 3
• Even unintentional exposures can cause toxicity, though serious effects are rare (0.7% in unintentional adult exposures) 3
• Two deaths occurred in a 20-year poison center review, both from intentional exposures 3
• No standard treatment guidelines exist for benzonatate toxicity, with management limited to supportive care 3

Drug Interaction Assessment

ACE Inhibitor Consideration

• The patient is taking donepezil (not an ACE inhibitor as stated—donepezil is a cholinesterase inhibitor for dementia)
• If the patient were on an ACE inhibitor (like perindopril), ACE inhibitor-induced cough should be ruled out first before adding antitussive therapy 7, 8, 9
• ACE inhibitor cough typically resolves within 1-4 weeks of discontinuation 7, 9

Lorazepam Interaction

• The patient is taking lorazepam, which can cause CNS depression
• Combining benzonatate with benzodiazepines may increase sedation risk, particularly concerning in elderly patients with dementia 1

Practical Management Algorithm

Step 1: Assess Cough Severity and Etiology

• Determine if cough is distressing enough to warrant pharmacologic intervention 1
• Ensure cough is from COVID-19/influenza/pharyngitis and not from other causes (aspiration, heart failure, medication-induced) 1

Step 2: Implement Non-Pharmacological Measures First

• Controlled breathing techniques and positioning 1
• Adequate hydration (no more than 2 liters daily) 1
• Treatment of fever with acetaminophen if present 1

Step 3: Pharmacologic Treatment Selection

Preferred option:

• Codeine phosphate 15-30 mg every 4-6 hours as needed 1
• Or morphine sulfate immediate-release 2.5-5 mg every 2-4 hours if cough is severe and distressing 1

If benzonatate must be used:

• Standard dose: 100-200 mg three times daily 1
• Ensure caregiver supervision to prevent chewing/dissolving capsules 2, 3
• Limit quantity prescribed to minimize overdose risk 3
• Educate caregiver about signs of toxicity: confusion, seizures, cardiac symptoms 2

Step 4: Monitoring Requirements

• Close caregiver supervision of medication administration given dementia diagnosis 4, 5
• Monitor for excessive sedation, especially with concurrent lorazepam use 1
• Reassess cough severity within 48-72 hours 1

Common Pitfalls to Avoid

• Do not prescribe benzonatate without ensuring proper caregiver supervision in patients with dementia—risk of improper administration is substantial 4, 5
• Do not use benzonatate as first-line when codeine-based antitussives have better evidence in acute respiratory infections 1
• Do not prescribe large quantities given overdose risk and limited treatment options for toxicity 3
• Do not combine with multiple CNS depressants without careful monitoring 1