Should a patient take benzonatate (generic name) when not coughing to maintain therapeutic effects?

Benzonatate Should Only Be Taken When Coughing Occurs, Not Prophylactically

Benzonatate should be taken only when needed for symptomatic relief of cough, not on a scheduled basis when not experiencing cough symptoms. 1 Taking benzonatate when not coughing provides no therapeutic benefit and unnecessarily exposes patients to potential side effects.

Mechanism of Action and Dosing

Benzonatate works peripherally by anesthetizing stretch receptors in the respiratory passages, lungs, and pleura, reducing the cough reflex at its source. It:

• Begins acting within 15-20 minutes
• Effects last for 3-8 hours
• Has no inhibitory effect on the respiratory center at recommended dosages 1

The FDA-approved dosing is:

• 100-200 mg three times daily as needed for cough
• Maximum daily dose: 600 mg in three divided doses
• Capsules must be swallowed whole (not broken, chewed, dissolved, cut, or crushed) 1

Evidence Supporting "As-Needed" Use

The American College of Chest Physicians guidelines specifically position benzonatate as a local anesthetic to be used for intractable cough that has not responded to other approaches 2. It is considered a third-line agent after:

1. Demulcents (first-line)
2. Opiate derivatives (second-line)
3. Peripherally-acting antitussives (third-line) 2

In lung cancer patients with opioid-resistant cough, benzonatate is suggested as a trial therapy when other pharmacological approaches have failed 2. This positioning as a rescue medication supports its use only when symptoms are present.

Safety Considerations

Taking benzonatate unnecessarily increases risk without benefit:

• Benzonatate has structural similarities to local anesthetics like tetracaine and procaine 3
• Overdose can lead to serious adverse effects including seizures, dysrhythmias, and cardiac arrest 3, 4
• Cases of torsades de pointes and cardiac arrest have been reported even in pediatric patients 5
• As a local anesthetic, benzonatate can increase the risk of aspiration, which is particularly concerning in frail patients 2

Clinical Approach to Benzonatate Use

For patients with chronic cough requiring benzonatate:

1. Use only when symptomatic: Take 100-200 mg when cough occurs, not on a scheduled basis
2. Limit frequency: Do not exceed three doses per day or 600 mg total daily
3. Monitor effectiveness: If cough is not controlled, consult healthcare provider rather than increasing dose
4. Discontinue if ineffective: If a short course does not lead to improvements, the treatment should be discontinued and another approach tried 2

Special Considerations

For patients with lung cancer or other advanced diseases:

• Benzonatate may be particularly useful for opioid-resistant cough 6
• Assessment of aspiration risk should be performed before prescribing 2
• Pretreatment with a beta-agonist by handheld inhaler or nebulizer is recommended due to risk of bronchospasm 2
• Patients should be advised not to eat or drink for about an hour after treatment due to reduced sensitivity of the cough reflex 2

Bottom Line

Benzonatate is indicated for symptomatic relief of cough only. Taking it prophylactically when not coughing provides no therapeutic benefit while unnecessarily exposing the patient to potential adverse effects. The medication should be used on an as-needed basis for active cough symptoms, not as a scheduled medication to maintain therapeutic levels.