Benzonatate is a medication prescribed for the symptomatic relief of cough. It is administered in capsule form and begins to work within 15 to 20 minutes after being taken by mouth, with its effects lasting between 3 and 8 hours. Understanding how the body processes this medication can help clarify how long it generally stays in one’s system.
Understanding Benzonatate
Benzonatate is classified as a non-narcotic antitussive. Its role is to alleviate cough symptoms from acute conditions like the common cold or bronchitis, or chronic issues such as emphysema. The medication works by targeting specific areas within the respiratory system.
Benzonatate’s mechanism of action involves numbing the stretch receptors found in the respiratory passages, lungs, and pleura. These receptors initiate the cough reflex when irritated. By reducing their activity, benzonatate inhibits the cough reflex. It may also influence the transmission of cough reflex impulses in the brain’s medulla, contributing to cough suppression. Benzonatate is chemically similar to local anesthetics such as procaine and tetracaine, explaining its numbing properties.
How the Body Processes Benzonatate
The body’s process for handling medications involves several steps, including absorption, metabolism, and elimination. After oral administration, benzonatate is absorbed into the bloodstream through the gastrointestinal tract. The drug’s elimination half-life, a measure of how long it takes for half of the drug to be removed from the body, is reported to be approximately 1 hour in healthy individuals, though some studies suggest it could be around 3.8 hours. This means that while effects may last for several hours, the drug is quickly processed and removed.
Benzonatate is primarily broken down in the liver through a process called ester hydrolysis, where it is converted into a metabolite called 4-(butylamino)benzoic acid (BABA) by enzymes like plasma butyrylcholinesterase (BChE). This metabolite is believed to be inactive. The exact route and rate of the drug’s excretion from the body are not extensively documented, but it is thought to occur mainly through renal excretion.
Several individual factors can influence how quickly benzonatate is processed and eliminated from the body. Metabolic rate plays a role; faster metabolisms may clear the drug more quickly. Liver and kidney function is also significant, as these organs are central to drug metabolism and excretion. Impaired liver or kidney function can slow down the removal of benzonatate, potentially leading to higher drug levels for longer periods.
Dosage and frequency of medication can also affect its presence in the body. Higher or more frequent doses might lead to greater drug accumulation. Age and overall health can also influence drug processing. For instance, elderly individuals or those with compromised health might metabolize and excrete medications at a slower rate. Genetic factors can also influence the activity of drug-metabolizing enzymes, leading to variations in how quickly benzonatate is cleared.
Important Safety Information
Benzonatate is generally well-tolerated when taken as directed, but specific safety information is important to consider. Common side effects can include drowsiness, dizziness, headache, nausea, constipation, and skin rash. These effects are mild and may lessen as the body adjusts to the medication. If drowsiness or dizziness occurs, caution is advised when driving or operating machinery.
Overdose is a serious concern with benzonatate, and symptoms can appear rapidly, often within 15 to 60 minutes after ingestion. Signs of an overdose may include restlessness, tremors, convulsions, and abnormal heart rhythms, which can progress to cardiac arrest and death. Even a small number of capsules can be fatal, particularly for children under 10. Immediate medical attention is necessary if an overdose is suspected.
Swallow benzonatate capsules whole without chewing, crushing, or dissolving them. If the capsule contents are released in the mouth, it can cause temporary numbness of the mouth and throat, leading to a choking sensation. This local anesthetic effect can also result in more severe reactions like laryngospasm, bronchospasm, or circulatory collapse, especially if a hypersensitivity reaction occurs. There are no known interactions with food or non-alcoholic drinks, but alcohol consumption might increase the risk of sedation or dizziness.