Coughing is a common reflex that helps clear irritants and secretions from the airways. Many seek relief from persistent coughs through medications known as cough suppressants. These products reduce the frequency and intensity of coughing episodes.
How Cough Suppressants Work
Cough suppressants function through two mechanisms: central and peripheral action. Centrally acting suppressants target the cough reflex center in the brainstem, reducing signals that trigger a cough.
Other suppressants numb cough receptors in the respiratory tract. These receptors send signals to the brain that initiate the cough reflex. By desensitizing these peripheral receptors, medications diminish the urge to cough.
Types of Cough Suppressants and Their Efficacy
Over-the-counter (OTC) cough suppressants commonly contain active ingredients such as Dextromethorphan (DM). While widely used, scientific evidence regarding its effectiveness for coughs associated with acute upper respiratory tract infections can be mixed, with some studies showing little significant difference compared to placebo. However, some research suggests DM may reduce daytime cough frequency in children with common colds.
Prescription cough suppressants, such as codeine or hydrocodone, are stronger antitussive agents. These opioid-based medications work by binding to opioid receptors in the central nervous system, suppressing the cough reflex. While effective, their use is limited by potential side effects, including drowsiness, dizziness, nausea, constipation, and the risk of misuse or addiction. The FDA has restricted the use of codeine and hydrocodone for cough to adults 18 years and older due to these risks, particularly in children.
Cough suppressants differ from expectorants, like guaifenesin. Expectorants do not suppress cough; instead, they thin and loosen mucus in the airways, making it easier to cough up. Guaifenesin helps clear congestion by increasing the volume and reducing the stickiness of respiratory secretions. Suppressants are generally more appropriate for dry, unproductive coughs, while expectorants are for coughs with mucus.
Considerations and When to Seek Medical Advice
Cough suppressants are generally suited for dry, non-productive coughs that can interfere with sleep or daily activities. These medications address the symptom of coughing but do not treat the underlying cause of the cough. It is important to adhere strictly to dosage instructions provided on the product label or by a healthcare professional. Overdosing, especially with combination products that contain multiple active ingredients, can lead to serious side effects. Common side effects can include drowsiness, dizziness, and gastrointestinal discomfort.
Medical advice should be sought if a cough persists longer than 7 to 10 days, or if it is accompanied by concerning symptoms. These symptoms include a high or persistent fever, shortness of breath, chest pain, wheezing, or coughing up blood or thick, discolored phlegm. For infants and very young children, caution is advised, as many over-the-counter cough and cold medicines are not recommended for those under specific age limits due to safety concerns and a lack of proven efficacy. Individuals with pre-existing health conditions should consult their doctor before using cough suppressants to avoid potential interactions or complications.