Dextromethorphan (DXM) is a widely available over-the-counter (OTC) cough suppressant found in many cold and flu preparations. It offers temporary relief from coughing, making it a common choice for managing respiratory illness symptoms. Understanding its proper use is important for both effectiveness and safety.
What Dextromethorphan Is
Dextromethorphan functions as an antitussive, suppressing the cough reflex. It targets the cough center in the brain. Though derived from opioids, DXM does not typically cause opioid-like analgesic or addictive effects at recommended doses. This medication is available in various forms, including syrups, tablets, liquid-filled capsules, dissolving strips, and lozenges. DXM is often combined with other active ingredients in multi-symptom cold and flu medications.
Recommended Dosing for Dextromethorphan
Recommended dosing is crucial for safe and effective use. For adults and adolescents 12 years and older, a typical immediate-release dose is 10-20 milligrams every four hours, or 30 milligrams every six to eight hours. The maximum daily dose should not exceed 120 milligrams within 24 hours. Extended-release formulations often have different schedules, such as 60 milligrams every 12 hours, with a maximum of 120 milligrams in 24 hours.
For children, age-based guidelines apply; DXM is generally not recommended for those under four. Children aged four to five may take 2.5-5 mg every four hours (max 30 mg/24 hours). For ages six to 11, immediate-release doses are typically 5-10 mg every four hours or 15 mg every six to eight hours (max 60 mg/24 hours). Extended-release options for this group are 30 mg every 12 hours.
Always read the Drug Facts label on any product containing dextromethorphan, as concentrations vary. Use the provided measuring device for liquid formulations to ensure accurate dosing. These are general guidelines; always follow specific product instructions to prevent accidental overdose.
Key Safety Considerations
Key safety considerations extend beyond dosage. Be aware of potential drug interactions, particularly with monoamine oxidase inhibitors (MAOIs). Taking DXM within 14 days of an MAOI can lead to serotonin syndrome due to excessive serotonin levels.
SSRIs, common antidepressants, also increase serotonin levels, heightening serotonin syndrome risk when combined with DXM. Always check active ingredients in all medications, as DXM is often in combination products. This prevents accidental excessive intake and unintended drug interactions.
Individuals with pre-existing medical conditions should use caution. Those with liver impairment may experience prolonged effects, as DXM is metabolized in the liver. For individuals with asthma, DXM can decrease the cough reflex, making it harder to clear mucus. Its use is not recommended during an acute asthma attack. Pregnant or breastfeeding individuals should consult a healthcare professional before use, as effects on unborn or nursing infants are a consideration.
Recognizing Excessive Dextromethorphan Intake
Excessive DXM intake can lead to adverse effects. Mild signs include nausea, vomiting, dizziness, drowsiness, unsteadiness, nervousness, or restlessness. These symptoms often appear within 15-30 minutes of ingestion and can last for several hours.
More severe signs include confusion, blurred vision, rapid heartbeat, hallucinations, difficulty breathing, seizures, or significantly elevated body temperature. If severe symptoms occur or overdose is suspected, seek immediate medical attention. Contact poison control or emergency medical care for prompt assessment and treatment.