What is benzonatate?
Benzonatate is a non-narcotic, prescription medication used to provide symptomatic relief from coughing. It is available under brand names such as Tessalon Perles, which are often described as small, liquid-filled capsules that resemble jelly beans. Since its FDA approval in 1958, its use has increased significantly, becoming a widely prescribed cough suppressant. Unlike over-the-counter cough medicines, benzonatate requires a doctor's prescription due to its specific mechanism of action and the serious risks associated with improper use or accidental ingestion. It is chemically related to other anesthetic agents, which explains its unique numbing properties.
Mechanism of action: How benzonatate works
Benzonatate's effectiveness comes from its dual mechanism of action, affecting both the peripheral and central nervous systems to suppress the cough reflex.
- Peripheral action: The drug's primary function is to anesthetize, or numb, the stretch receptors in the lungs, airways, and pleura (the membranes covering the lungs). By desensitizing these nerve endings, benzonatate raises the threshold at which the cough reflex is triggered, making it less sensitive to irritation.
- Central action: Benzonatate also has a central effect, working to suppress the cough center in the brain's medulla. However, unlike other cough suppressants, it does so without depressing the respiratory center at recommended dosages, which helps differentiate it from narcotics.
This combination of peripheral and central action makes benzonatate an effective antitussive for controlling coughing associated with various respiratory conditions. The onset of action is relatively fast, typically within 15 to 20 minutes after swallowing, with effects lasting between 3 and 8 hours.
Approved uses and indications
Healthcare providers may prescribe benzonatate for the symptomatic relief of cough caused by a variety of respiratory conditions in adults and children over 10 years old. These conditions can include:
- Bronchitis
- Common cold
- Flu (influenza)
- Pneumonia
- Chronic obstructive pulmonary disease (COPD)
- Other lung irritations
It is important to note that benzonatate is intended for the symptomatic relief of cough and does not treat the underlying cause of the illness. Its use is not recommended for chronic coughs resulting from conditions like smoking, asthma, or emphysema where there is significant mucus production, as it can hinder the body's ability to expel phlegm.
Important safety information and proper administration
Proper administration is critical for the safe use of benzonatate. The liquid-filled capsules must be swallowed whole and should never be broken, chewed, crushed, or dissolved.
- Risk of local anesthesia: If the capsule is compromised in the mouth, the contents can be released, causing a rapid and temporary numbing of the mouth, tongue, and throat. This can lead to a dangerous choking sensation or breathing difficulties.
- Hypersensitivity reactions: Severe allergic reactions, such as bronchospasm (airway constriction), laryngospasm (vocal cord constriction), and cardiovascular collapse, can occur, especially if the drug is chewed or sucked on.
- Ingestion by children: The FDA has issued a drug safety warning regarding accidental ingestion by children younger than 10 years of age, which can be fatal. Even one or two capsules can be life-threatening for a small child, with symptoms appearing rapidly, often within 15 to 20 minutes. For this reason, benzonatate must be stored in a child-resistant container and kept out of a child's reach at all times.
Common and serious side effects
While many people tolerate benzonatate well when taken as prescribed, it is associated with a range of possible side effects.
Common side effects include:
- Dizziness
- Drowsiness
- Headache
- Nausea and stomach upset
- Constipation
- Stuffy nose
- Chills
- Burning sensation in the eyes
Serious side effects requiring immediate medical attention can include:
- Confusion or hallucinations
- Numbness or tingling in the mouth, throat, or chest
- Severe allergic reactions (hives, itching, swelling of the face, tongue, or throat)
Benzonatate vs. other cough medications: A comparison
Benzonatate differs significantly from other commonly used antitussives, such as dextromethorphan, in its mechanism, availability, and specific warnings.
| Feature | Benzonatate (Tessalon Perles) | Dextromethorphan (Delsym, Robitussin DM) |
|---|---|---|
| Availability | Prescription-only | Over-the-counter (OTC) |
| Mechanism of Action | Local anesthetic numbing lungs and airways (peripheral) and suppresses central cough center | Acts solely on the cough center in the brain (central) |
| Age Restriction | Approved for adults and children 10 years and older due to fatality risk in younger children | Varies by product, but often used for children over the age of 4 |
| Administration | Must be swallowed whole to prevent choking or local anesthesia | Available in liquid, capsule, or lozenge forms |
| Serious Risks | Severe reactions possible if chewed; fatal in young children if ingested | Potential for serotonin syndrome when combined with certain medications |
Conclusion
The drug commonly referred to as "benzon" is actually benzonatate, a prescription antitussive that works by anesthetizing stretch receptors in the lungs and suppressing the cough reflex in the brain. While effective for relieving cough in patients over 10 when used correctly, it carries significant risks, most notably the potential for fatal overdose in young children and serious allergic reactions if the capsule is chewed or broken. It is crucial for patients to follow all prescribed instructions and to store the medication securely away from children. Always consult a healthcare provider to ensure safe and appropriate use. For more information, you can visit the FDA's official safety communication regarding benzonatate.
