What Does Benzonatate Do? Understanding this Prescription Cough Suppressant

October 7, 2025 •

4 min read

Benzonatate, a prescription cough suppressant first approved in the U.S. in 1958, provides relief by acting as an anesthetic to calm the cough reflex. This detailed guide explains exactly what does benzonate do and how it differs from common over-the-counter remedies.

Quick Summary

Benzonatate is a prescription antitussive medication used to relieve coughs. It works by numbing stretch receptors in the lungs, dampening the cough reflex centrally in the brain. It is crucial to swallow the capsules whole to avoid serious side effects.

Key Points

Peripheral Anesthetic: Benzonatate works by numbing the stretch receptors in the lungs and airways, which are responsible for triggering the cough reflex.
Central Action: It also suppresses the cough reflex in the medulla region of the brain, offering a dual mechanism of action.
Proper Administration is Critical: Capsules must be swallowed whole without chewing or sucking to prevent the drug from releasing locally and causing serious numbing effects in the mouth and throat.
Fatal Overdose Risk in Children: Accidental ingestion by children under 10 is extremely dangerous and can be fatal. The medication should be stored securely out of their reach.
Prescription Only: Benzonatate is not an over-the-counter product and requires a doctor's prescription.
Avoid Certain Combinations: It can interact with other sedating medications, alcohol, and certain psychiatric drugs, increasing the risk of adverse effects.

Understanding the Mechanism of Benzonatate

Benzonatate is a non-narcotic prescription medication primarily used to relieve symptoms of cough caused by various respiratory conditions. Its unique mechanism of action sets it apart from many over-the-counter (OTC) cough medicines. Instead of working solely on the central nervous system like some opioid-based antitussives, benzonatate provides a dual-action effect.

First, benzonatate acts as a local anesthetic, or numbing agent, on specific receptors in the respiratory system. It anesthetizes the stretch receptors of the vagal afferent nerves found in the bronchi, alveoli, and pleura in the lower airways and lungs. These nerve endings are responsible for triggering the cough reflex when they detect irritation. By desensitizing them, benzonatate significantly reduces the urge to cough.

Second, the medication also exhibits a central antitussive effect. It suppresses the transmission of the cough reflex within the central nervous system at the level of the medulla. This combination of peripheral and central action makes it an effective tool for managing persistent, dry coughs associated with conditions such as bronchitis, pneumonia, and the common cold. It is important to note that benzonatate does not treat the underlying cause of the cough but rather offers symptomatic relief.

Proper Usage and Precautions

Proper administration is critical when taking benzonatate to ensure its safety and effectiveness. The medication is available as liquid-filled capsules that must be swallowed whole.

Never chew, suck, or crush the capsules. Improper administration can release the numbing medication into the mouth and throat, causing temporary numbness. This can lead to a choking sensation, difficulty swallowing, and serious hypersensitivity reactions, including bronchospasm and cardiovascular collapse.
If accidental chewing or sucking occurs, contact a healthcare provider immediately if numbness persists or worsens.
Keep benzonatate in a child-resistant container and out of reach of children. The small, pearl-like appearance of the capsules can be mistaken for candy, and accidental ingestion by young children has led to rapid overdose and death.

Common and Severe Side Effects

While generally well-tolerated, benzonatate can cause a range of side effects. Most are mild, but some serious reactions can occur, especially with improper use.

Common Side Effects: dizziness, drowsiness, headache, nausea, constipation, stuffy nose, and a burning sensation in the eyes.
Serious Side Effects: Confusion, hallucinations, allergic reactions (hives, difficulty breathing), and severe numbness in the mouth, chest, or face. If you experience these, seek immediate medical attention.

Comparing Benzonatate and Dextromethorphan

For many patients, the choice of a cough suppressant comes down to prescription benzonatate or over-the-counter dextromethorphan. While both are effective, they have different mechanisms, administration requirements, and potential side effects.


Feature	Benzonatate (Tessalon Perles)	Dextromethorphan (Delsym, Robitussin DM)
Prescription Status	Prescription only	Available over-the-counter
Mechanism of Action	Numbing agent for lung stretch receptors and central cough reflex suppressant	Acts centrally on the brain's cough center to raise the cough threshold
Administration	Swallow capsule whole; do not chew or suck due to numbing risk	Oral liquid, tablet, or lozenge; often available in combination products
Onset of Action	15–20 minutes	Varies by formulation
Duration	3–8 hours	Varies by formulation, often longer than benzonatate
Common Side Effects	Drowsiness, headache, dizziness, nausea	Nausea, stomach upset, mild drowsiness
Serious Risks	Fatal overdose in children, accidental numbing and choking	Serotonin syndrome with MAOI use, potential for abuse at high doses

Drug Interactions

Before taking benzonatate, it is essential to inform your doctor or pharmacist about all other medications, vitamins, and supplements you are taking. Combining benzonatate with other sedating drugs can worsen side effects like dizziness and drowsiness. Common interacting substances include:

Alcohol: Can intensify side effects like dizziness and sleepiness.
Anesthesia Medications: Chemically related to some anesthetics like tetracaine and procaine; concurrent use can lead to excessive drowsiness.
Opioid Pain Medications: Can increase the risk of slowed breathing and excessive sedation.
Certain Mental Health Medications: Rare psychiatric side effects like confusion and hallucinations may be more likely when taken with monoamine oxidase inhibitors (MAOIs) or tricyclic antidepressants.
OTC Antihistamines: Older antihistamines like Benadryl (diphenhydramine) can worsen drowsiness.

Conclusion

In summary, benzonatate is a unique, prescription-only antitussive that suppresses cough by numbing peripheral receptors in the lungs and acting on the central cough reflex. While effective, it requires strict adherence to proper administration, namely swallowing the capsules whole, to avoid serious and potentially fatal side effects, especially in children under 10. When taken correctly and with awareness of its potential drug interactions, benzonatate can provide significant relief for persistent coughs. Always consult a healthcare professional to determine if it is the right medication for your specific condition.

For additional information and precautions, refer to the Drugs.com patient tips for benzonatate.

Frequently Asked Questions

Benzonatate typically begins to work within 15 to 20 minutes of oral administration. The effects of a single dose generally last for 3 to 8 hours.

Benzonatate is prescribed for symptomatic relief of coughs due to the common cold, flu, and certain chronic conditions like bronchitis and pneumonia. It is not intended for chronic coughs associated with smoking, asthma, or emphysema where there is significant mucus.

Chewing or crushing benzonatate capsules can cause rapid numbing of the mouth, tongue, and throat, which can lead to a choking sensation, difficulty swallowing, and in severe cases, allergic reactions like laryngospasm and cardiovascular collapse.

No, benzonatate is not recommended for children under 10 years of age due to the risk of accidental overdose, which can be fatal. Even small amounts can be dangerous for young children.

No, benzonatate is a non-narcotic cough suppressant and is not considered addictive. It works by anesthetizing nerve endings rather than affecting the brain's opioid receptors.

It is best to avoid or limit alcohol consumption while taking benzonatate. Both can cause dizziness and drowsiness, and combining them may intensify these side effects.

Benzonatate is typically taken three times daily as needed. It's important to follow your healthcare provider's instructions regarding the frequency of doses.