Benzonatate, often recognized by the brand name Tessalon Perles, is a prescription medication used to calm persistent coughing. It functions as a non-narcotic antitussive, suppressing the cough reflex without acting centrally in the brain like opioid-based suppressants. The drug works peripherally by anesthetizing the stretch receptors located in the lungs, pleura, and respiratory passages. This effectively dampens the signal that triggers the cough. Its effects usually begin within 15 to 20 minutes after ingestion and can last for up to eight hours. While benzonatate is generally safe and effective when taken as directed, understanding which medications and substances to avoid is important for patient safety.
Absolute Contraindications for Use
Benzonatate is not appropriate for every patient, and there are specific conditions under which its use is inadvisable. Individuals with a known allergy or hypersensitivity to benzonatate should not take the medication. This warning extends to people with sensitivities to related compounds, such as ester-type anesthetics like procaine and tetracaine, which belong to the para-amino-benzoic acid (PABA) chemical class.
The medication carries a specific restriction regarding age due to the severe risks associated with accidental ingestion. Benzonatate is not recommended for children under the age of ten years. Overdose in this younger age group can be rapidly severe, with symptoms appearing within 15 to 20 minutes and potentially leading to death within an hour.
Patients must strictly follow instructions to swallow the capsule whole, without chewing, sucking, or crushing it. If the drug is released in the mouth, it can cause local numbness, presenting a choking hazard and potentially leading to a severe allergic reaction. Symptoms such as tightness in the throat, difficulty breathing, or hives require immediate medical attention, as they can indicate a serious hypersensitivity reaction.
Interactions with Central Nervous System Depressants
A major safety consideration when taking benzonatate involves its interaction with substances that slow down the brain and nervous system, known as central nervous system (CNS) depressants. Combining these substances creates an additive effect, increasing the potential for unwanted side effects. This combination significantly raises the risk of excessive drowsiness, profound dizziness, and impaired judgment.
One of the most important substances to avoid is alcohol, which acts as a powerful CNS depressant. Consuming alcohol while taking benzonatate can intensify sedation and dizziness, increasing the risk of accidents and falls. Patients should also exercise caution with prescription pain medications, particularly opioids or narcotics, such as oxycodone, hydrocodone, or codeine. Since these drugs already slow respiratory function, combining them with benzonatate heightens the danger of respiratory depression, where breathing becomes dangerously shallow.
Prescription medications used for anxiety, sleep, or muscle relaxation also fall into the category of CNS depressants. This includes benzodiazepines, such as alprazolam or diazepam, and various prescription sleep aids. Taking benzonatate concurrently with any of these drugs can lead to an unsafe level of sedation and confusion. Muscle relaxants should similarly be avoided or used only under direct medical supervision to prevent over-sedation.
Avoiding Over-the-Counter Combinations
The risk of adverse effects is not limited to prescription drugs; many common over-the-counter (OTC) cold and allergy products can also interact negatively with benzonatate. The primary concern is the duplication of sedating effects and the risk of accidental overdose by combining multiple cough suppressants.
Many OTC allergy and cold remedies contain first-generation antihistamines, such as diphenhydramine, which are known to cause significant drowsiness. Combining these sedating antihistamines with benzonatate can lead to an unacceptable level of sleepiness, lightheadedness, and difficulty concentrating. This additive sedation can compromise a person’s ability to safely operate machinery or drive.
Another important class to avoid is other cough suppressants, notably those containing dextromethorphan (DXM). Although benzonatate and DXM work through different mechanisms, taking both can result in an increased likelihood of experiencing side effects like dizziness, confusion, and over-suppression of the cough reflex. It is advisable to use only one type of cough medication at a time unless explicitly directed otherwise by a healthcare professional.
Individuals must carefully read the labels on all combination cold and flu products before taking them with benzonatate. These multi-symptom remedies often contain several active ingredients, including antihistamines or other suppressants, which can inadvertently lead to drug duplication or heightened side effects. Consulting a pharmacist before combining benzonatate with any OTC product helps ensure that there are no hidden ingredients that might cause an unsafe interaction.