Please check your internet connection and try again.
# Dextromethorphan
## Overview
Dextromethorphan is a cough suppressant (antitussive) that acts centrally on the cough center in the medulla. It is available in various formulations, often in combination with other agents.
## Primary Indications
Symptomatic relief of cough due to minor throat and bronchial irritation.
## Adult Dosing
* **Immediate-release:** 10-20 mg every 4 hours, or 30 mg every 6-8 hours.
* Maximum: 120 mg per 24 hours.
* **Extended-release:** 60 mg every 12 hours.
* Maximum: 120 mg per 24 hours.
Dosing for combination products will vary based on the specific formulation and may require adjustment if dextromethorphan is present at a different concentration.
## Pediatric Dosing
* **Ages 6 to 12 years:** 5-10 mg every 4 hours, or 15 mg every 6-8 hours.
* Maximum: 60 mg per 24 hours.
* **Ages 2 to 6 years:** 2.5-5 mg every 4 hours, or 7.5 mg every 6-8 hours.
* Maximum: 30 mg per 24 hours.
**Note:** Use in children under 6 years of age should be based on clinical judgment and physician guidance, as safety and efficacy are not well established for this age group. Some guidelines recommend avoiding use in children under 4 years of age.
## Dose Adjustments
No dose adjustments are typically required for renal or hepatic impairment, however, caution is advised in severe hepatic impairment due to potential for increased drug exposure.
## Contraindications
* Hypersensitivity to dextromethorphan or any component of the formulation.
* Concomitant use with or within 2 weeks of discontinuing monoamine oxidase inhibitors (MAOIs).
* Use in patients currently taking selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), or other centrally acting serotonergic agents may increase the risk of serotonin syndrome.
## Adverse Effects
Common: Dizziness, drowsiness, nausea, vomiting, nervousness.
Less common: Confusion, hallucinations, respiratory depression (at high doses), serotonin syndrome (rare, but serious).
## Key Drug Interactions
* **Monoamine Oxidase Inhibitors (MAOIs):** Potentially fatal serotonin syndrome or hypertensive crisis.
* **Serotonergic Agents (SSRIs, SNRIs, TCAs, triptans, St. John's Wort, etc.):** Increased risk of serotonin syndrome.
* **CYP2D6 Inhibitors (e.g., fluoxetine, paroxetine, quinidine):** May increase dextromethorphan plasma concentrations, increasing the risk of adverse effects.
* **Alcohol and other CNS depressants:** Additive sedative effects.
## Monitoring
Monitor for effectiveness in suppressing cough and for adverse effects, particularly CNS effects and signs of serotonin syndrome (agitation, confusion, rapid heart rate, fever, sweating, muscle rigidity, etc.).
## Clinical Pearls
* Dextromethorphan is available in many over-the-counter (OTC) cough and cold preparations, often in combination with other active ingredients like decongestants, antihistamines, expectorants, and analgesics. Carefully review all ingredients in combination products to avoid duplicate therapy and potential for adverse drug events.
* Patients should be advised against exceeding recommended doses due to the risk of serious adverse effects, including hallucinations and respiratory depression.
* Dextromethorphan has a potential for abuse and misuse.
***
**Disclaimer:** This information is intended for healthcare professionals and is not a substitute for professional medical advice. Always consult the most current prescribing information and product monographs for complete and up-to-date details before making any clinical decisions. Local institutional protocols may also apply.
