A persistent cough can be disruptive, interfering with daily activities and sleep. For those seeking relief, cough suppressants, known as antitussives, can reduce its frequency and intensity.
Understanding Antitussives: Purpose and Function
Antitussives are medications that suppress the cough reflex, reducing the urge to cough. They provide relief from dry, irritating, non-productive coughs, which are those where no mucus or phlegm is expelled.
Antitussives differ from expectorants, such as guaifenesin, which thin and loosen mucus for easier expulsion. Antitussives are not recommended for productive coughs, as suppressing them can lead to mucus buildup and increased infection risk.
How Antitussives Work
Antitussives interact with the body’s cough reflex pathway. The reflex starts when nerve receptors in the throat and airways are stimulated, sending signals to the cough center in the brainstem, which then triggers a cough.
Centrally-acting antitussives inhibit the cough center in the brainstem, reducing the brain’s signal to cough. Other antitussives act peripherally, affecting nerve receptors in the respiratory passages and lungs, desensitizing them and reducing cough signals to the brain.
Common Types of Antitussives
Antitussive medications are categorized into opioid-based and non-opioid types, each with distinct characteristics and availability. Opioid antitussives, such as codeine and hydrocodone, are often prescription-only and are considered potent cough suppressants. These drugs are thought to act centrally on mu-opioid receptors in the central nervous system, directly suppressing the cough reflex in the medulla.
Non-opioid antitussives are widely available over-the-counter. Dextromethorphan (DM) is a common example, structurally similar to codeine but without its addictive properties or significant central nervous system depression. It also acts on the cough center in the medulla to suppress coughing. Another non-opioid type, benzonatate, functions as a peripherally-acting antitussive by numbing stretch receptors in the respiratory passages and lungs, thereby reducing the urge to cough.
Important Considerations for Use
Antitussives are appropriate for acute, non-productive coughs that interfere with daily life, such as those from colds or upper respiratory infections. Consult a healthcare professional for chronic coughs (lasting over two weeks) or those with concerning symptoms like fever or rash.
Potential side effects of antitussives can include dizziness, drowsiness, headache, nausea, constipation, and stomach upset. Opioid-based antitussives carry additional risks such as respiratory depression and dependence. Children, pregnant or breastfeeding individuals, and those with pre-existing conditions should exercise caution and seek medical advice before using these medications. Always adhere to the dosage instructions on the label and discuss any other medications or supplements with a healthcare provider to avoid potential drug interactions, especially with dextromethorphan and MAO inhibitors.