A cough can be an uncomfortable symptom of various conditions, from the common cold to allergies. Many people turn to over-the-counter cough suppressants for relief, aiming to quiet a persistent cough. These medications work by targeting the body’s cough reflex, helping to reduce the frequency and intensity of coughing. Understanding how to use these products correctly, including appropriate dosages, is important for both safety and effectiveness.
Understanding Common Cough Suppressants
Over-the-counter cough suppressants typically contain active ingredients that act on the central nervous system to reduce the urge to cough. Two common examples are Dextromethorphan (DXM) and Diphenhydramine. Dextromethorphan works by decreasing activity in the part of the brain responsible for the cough reflex, acting as an antitussive.
Diphenhydramine is primarily an antihistamine that also possesses cough-suppressing properties. It helps to block histamine receptors and has mild sedative effects, which can aid in quieting coughs, particularly those associated with minor throat or bronchial irritation. It is important to distinguish cough suppressants from expectorants, such as guaifenesin. While suppressants reduce the cough reflex, expectorants thin and loosen mucus in the airways for easier clearance.
Following Dosage Instructions
Determining the correct dosage for cough suppressants involves carefully reading the drug facts label on the product packaging. This label provides specific instructions regarding the recommended single dose, how often it can be taken, and the maximum daily dosage. Adhering to these limits is important to avoid potential adverse effects.
For Dextromethorphan, an adult may take 10 to 20 milligrams (mg) every four hours, or 30 mg every six to eight hours, for immediate-release formulations. The maximum daily dose for adults should not exceed 120 mg. If using an extended-release form, a common adult dosage is 60 mg every 12 hours. Do not use Dextromethorphan for more than seven days.
For Diphenhydramine, adults take 25 to 50 mg orally every four to six hours. The maximum daily dosage for cough relief is 150 mg per day. Diphenhydramine is for short-term use, a few days, to manage cough symptoms. Always use a specially marked spoon or cup for liquid medications to ensure an accurate dose.
Important Considerations Before Taking
Before taking a cough suppressant, be aware of potential side effects and interactions with other medications. Dextromethorphan can cause nausea, dizziness, drowsiness, and stomach discomfort. Higher doses may lead to agitation or panic. Diphenhydramine causes drowsiness, dizziness, and dry mouth, nose, or throat. It can also lead to impaired coordination and blurred vision.
Serious interactions can arise when cough suppressants are combined with other drugs. Dextromethorphan should not be taken with monoamine oxidase inhibitors (MAOIs) or within 14 days of stopping them, due to the risk of severe reactions like serotonin syndrome. Combining Dextromethorphan with selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants increases the risk of serotonin syndrome. Both Dextromethorphan and Diphenhydramine can increase the sedative effects of alcohol and other central nervous system depressants, causing increased drowsiness and dizziness.
Certain health conditions or populations need caution. Individuals with asthma, emphysema, or chronic bronchitis should use Dextromethorphan cautiously, especially if their cough produces excessive phlegm, as it can hinder mucus clearance. Diphenhydramine is not recommended for those with breathing problems. Liver disease can affect how the body processes these medications, potentially leading to drug buildup.
Older adults are more susceptible to side effects such as drowsiness, confusion, dry mouth, and an increased risk of falls. Pregnant or breastfeeding individuals should consult a healthcare provider before using cough suppressants.
When Professional Medical Advice is Needed
While over-the-counter cough suppressants can provide temporary relief, there are situations when professional medical advice is necessary. Consult a healthcare provider if a cough persists for more than seven days after taking Dextromethorphan, or a few days with Diphenhydramine, or generally for more than three weeks. Medical advice is also needed if the cough is accompanied by other symptoms, such as a high fever or one lasting several days.
Other concerning symptoms that warrant medical attention include:
- Rash, headache, sore throat, chest pain, shortness of breath, or wheezing.
- Unusual phlegm (thick, green, yellow, or bloody mucus).
- Night sweats, unexplained weight loss, difficulty swallowing, or fainting.
If a cough does not respond to over-the-counter medications, seek professional guidance. For suspected accidental overdose, contact poison control or seek emergency medical care immediately. Overdose symptoms can include severe sleepiness, nausea, vomiting, hallucinations, changes in blood pressure, a fast heartbeat, or seizures.