Benzonatate

Approved Indications:

• Symptomatic relief of cough associated with:
• Acute and chronic bronchitis
• Pneumonia
• Upper respiratory tract infections (e.g., pharyngitis, laryngitis)
• Chronic obstructive pulmonary disease (COPD)
• Influenza and other viral respiratory illnesses
• Postoperative cough (e.g., after bronchoscopy or thoracic surgery)
• Asthma (as adjunct therapy, not primary treatment)

Clinically Accepted Off-Label Uses:

• Persistent, non-productive cough that interferes with rest or recovery
• Cough-related insomnia where suppression is temporarily needed

Adults and Adolescents ≥10 years:

• Usual dose: 100 mg to 200 mg orally, three times daily as needed
• Maximum dose: 600 mg/day
• Administration route: Oral (capsule must be swallowed whole)

Pediatric Use (<10 years):

• Contraindicated due to risk of fatal overdose, even with a single capsule

Geriatric Patients:

• Use standard adult dosing
• Monitor closely for CNS side effects such as confusion or sedation

Renal or Hepatic Impairment:

• No formal adjustment guidelines available
• Use with caution; monitor for toxicity and CNS effects

Important Administration Instructions:

• Capsules must be swallowed whole with water
• Do not chew, suck, or dissolve the capsule in the mouth due to risk of:
• Oropharyngeal anesthesia
• Choking
• Laryngospasm or bronchospasm

Benzonatate is a peripherally acting antitussive. It works by anesthetizing stretch receptors located in the respiratory tract, including bronchi, alveoli, and pleura. This numbing effect reduces the sensitivity of these receptors to stimuli, thereby suppressing the cough reflex at its source. Benzonatate is chemically related to local anesthetics (e.g., procaine) and does not act centrally like codeine. The result is cough suppression without sedation or dependence.

• Absorption: Rapid after oral administration
• Onset of action: Within 15–20 minutes
• Duration of action: Approximately 3–8 hours
• Bioavailability: Not precisely established
• Distribution: Primarily to the respiratory tract tissues
• Metabolism: Rapid hydrolysis in plasma to para-aminobenzoic acid (PABA) and other metabolites
• Half-life: Approximately 3–8 hours
• Elimination: Renally excreted as metabolites in urine

• Pregnancy:
  No FDA-assigned pregnancy category; however, use is not recommended unless clearly necessary due to lack of sufficient human and animal data. Use with caution.
• Lactation:
  Unknown whether benzonatate is excreted in breast milk. Risk to nursing infants cannot be ruled out. Caution is advised during breastfeeding.
• General Advice:
  Avoid use in pregnant or lactating women unless the potential benefit outweighs the risk.

• Primary Class: Non-narcotic antitussive
• Subclass: Peripherally acting cough suppressant
• Chemical Relation: Ester-type local anesthetics

• Known hypersensitivity to benzonatate or related local anesthetics (e.g., tetracaine, procaine)
• Children under 10 years of age (due to life-threatening toxicity from even a single capsule)
• Inability to swallow capsules whole

• Pediatric risk:
  Even 1–2 capsules may cause death in children under 10 years. Symptoms (e.g., seizures, cardiac arrest) may occur within 15–60 minutes of ingestion.
  → Keep out of reach of children at all times.
• Capsule chewing hazard:
  If chewed or sucked, it may cause:
• Severe numbness of the mouth and throat
• Choking, laryngospasm, or bronchospasm
• Life-threatening airway compromise
• Central nervous system effects:
  May cause drowsiness, confusion, hallucinations, restlessness, or tremors.
• Overdose risk:
  Overdose is rapidly toxic and can result in:
• Seizures
• Cardiac arrest
• Coma
• Death
• Monitoring:
  Monitor patients for signs of CNS depression or allergic reactions, especially during initial use.

Common Side Effects:

• Drowsiness
• Dizziness
• Headache
• Constipation
• Nausea
• Nasal congestion
• Mild GI upset

Less Common:

• Rash
• Itching
• Chest numbness
• Visual disturbances

Serious (Rare but Severe):

• Seizures
• Laryngospasm
• Bronchospasm
• Cardiac arrest (especially after overdose or in children)
• Anaphylaxis
• Hallucinations or delirium

Timing & Severity:

• Effects typically occur within 30–60 minutes of dosing
• Risk increases with higher doses or improper use (e.g., chewing capsules)

Major Interactions:

• CNS depressants (e.g., opioids, benzodiazepines, sedating antihistamines, alcohol):
  Additive sedative effects; increased risk of respiratory depression
• Alcohol:
  May potentiate CNS effects such as drowsiness or confusion
• Local anesthetics:
  Structural similarity may cause cross-reactivity in patients allergic to ester-type anesthetics

Enzyme Involvement:

• Not metabolized via CYP450 system; interactions through hepatic enzymes are minimal

• Regulatory Warnings:
  The FDA and international health bodies have issued repeated alerts about the fatal toxicity of benzonatate in children under 10 years. Packaging now includes strong warnings and child-proofing requirements.
• Practice Trends:
  Increasingly recommended as a non-opioid alternative to codeine-based cough suppressants amid efforts to reduce opioid misuse.
• Labeling Revisions:
  Emphasis on proper administration (swallow whole) and strict pediatric safety precautions.

• Temperature: Store below 25°C (77°F)
• Humidity: Store in a dry place; avoid excess moisture
• Light Protection: Keep in original packaging; protect from light
• Handling Precautions:
• Do not chew or crush capsules
• Keep in child-resistant containers
• Ensure secure storage to prevent accidental ingestion by children