What is the recommended dose of benzonatate for an adult patient with acute cough and a history of cardiovascular disease, currently taking Plavix (clopidogrel)?

Benzonatate Dosing for Acute Cough

For acute cough in adults, benzonatate should be dosed at 100-200 mg three times daily as needed, with a maximum of 600 mg per day in three divided doses, and there are no known drug interactions between benzonatate and clopidogrel (Plavix), making concurrent use safe. 1

Standard Dosing Regimen

• The FDA-approved dose is 100-200 mg capsules three times daily as needed for cough 1
• If necessary to control cough, up to 600 mg daily in three divided doses may be given 1
• Capsules must be swallowed whole and should never be broken, chewed, dissolved, cut, or crushed 1

Critical Safety Considerations

Swallowing Instructions:

• Breaking or chewing benzonatate capsules can cause release of the medication in the mouth, producing temporary local anesthesia of oral mucosa and potential choking 1
• If numbness or tingling of the tongue, mouth, throat, or face occurs, patients must refrain from eating or drinking until numbness resolves 1

Overdose Risk:

• Overdosage resulting in death may occur in adults 1
• Do not exceed a single dose of 200 mg or total daily dosage of 600 mg 1
• Signs of overdose (restlessness, tremors, convulsions, coma, cardiac arrest) have been reported within 15-20 minutes, with death occurring within one hour of ingestion 1

Compatibility with Plavix (Clopidogrel)

There are no documented drug interactions between benzonatate and clopidogrel. Benzonatate is chemically related to para-amino-benzoic acid class anesthetic agents (procaine, tetracaine) and works as a peripherally-acting local anesthetic on the respiratory tract 1. Clopidogrel is metabolized primarily by CYP2C19 hepatic enzymes and works through ADP-dependent platelet inhibition 2, 3. These distinct mechanisms and metabolic pathways mean concurrent use is safe.

Clinical Context for Use

• Benzonatate is recommended as a local anesthetic option for opioid-resistant cough that does not respond to peripheral antitussives 4
• The CHEST guidelines suggest benzonatate as a trial option alongside nebulized lidocaine/bupivacaine for difficult-to-control cough 4
• Benzonatate is positioned as a later-line therapy, not first-line treatment for acute cough 4

Common Pitfalls to Avoid

• Never prescribe benzonatate to children under 10 years of age - accidental ingestion has resulted in death in this population 1
• Ensure patients understand the critical importance of swallowing capsules whole 1
• Keep benzonatate out of reach of children, as fatal overdose can occur rapidly 1
• Assess for prior sensitivity to related anesthetic agents (procaine, tetracaine) before prescribing 1

Cardiovascular Disease Considerations

For patients with cardiovascular disease on clopidogrel:

• Continue clopidogrel as prescribed - it is essential for preventing thrombotic events in patients with established cardiovascular disease 5, 3
• Benzonatate can be safely added without concern for drug interactions
• The standard benzonatate dosing of 100-200 mg three times daily applies regardless of cardiovascular comorbidities 1