Please check your internet connection and try again.
# Arsil (Dextromethorphan Hydrobromide)
## Overview
Dextromethorphan (DX) is a synthetic morphine derivative used primarily as an antitussive. Unlike codeine, it lacks significant analgesic or addictive properties at therapeutic doses, though it acts centrally on the cough center in the medulla to elevate the cough threshold.
## Primary Indications
Temporary relief of cough caused by minor throat and bronchial irritation (common cold or inhaled irritants).
## Adult Dosing
* **Immediate-Release (Liquid/Tablet/Strip):** 10–20 mg every 4 hours or 30 mg every 6–8 hours as needed.
* **Extended-Release:** 60 mg every 12 hours.
* **Maximum Dose:** 120 mg per 24 hours.
## Pediatric Dosing
* **Children 6–12 years:** 5–10 mg every 4 hours or 15 mg every 6–8 hours. Maximum: 60 mg/24 hours.
* **Children 4–6 years:** 2.5–5 mg every 4 hours. Maximum: 30 mg/24 hours.
* **Under 4 years:** Generally not recommended unless directed by a pediatrician due to lack of efficacy data and safety risks.
## Dose Adjustments
* **Hepatic Impairment:** Reduce dose or increase dosing interval in severe hepatic impairment, as dextromethorphan is extensively metabolized by the liver (CYP2D6).
* **Renal Impairment:** No specific adjustment required, but caution is advised in severe cases due to metabolite accumulation.
## Contraindications
* Hypersensitivity to dextromethorphan or excipients.
* Concomitant use with MAO inhibitors (MAOIs) or within 14 days of stopping MAOI therapy (risk of serotonin syndrome).
## Adverse Effects
* **Common:** Dizziness, drowsiness, nausea, vomiting, stomach pain.
* **Rare/High-Dose:** Confusion, ataxia, serotonin syndrome, hallucinations, and respiratory depression (at toxic doses).
## Key Drug Interactions
* **MAOIs (e.g., phenelzine, selegiline):** Life-threatening serotonin syndrome.
* **CYP2D6 Inhibitors (e.g., fluoxetine, paroxetine, quinidine):** May significantly increase plasma concentrations of dextromethorphan, increasing the risk of toxicity.
* **CNS Depressants (e.g., alcohol, opioids, benzodiazepines):** May enhance sedative effects.
## Monitoring
* Monitor frequency and severity of cough.
* Assess for signs of misuse or "robotripping" (dextromethorphan abuse).
* Re-evaluate if the cough persists for >7 days or is accompanied by fever, rash, or persistent headache.
## Clinical Pearls
* Dextromethorphan has no role in treating productive coughs associated with lower respiratory tract conditions like pneumonia or COPD/Asthma; suppressing these coughs can be harmful.
* It is frequently found in multi-ingredient OTC cold preparations; advise patients to check labels to avoid unintentional overdose from overlapping ingredients (e.g., acetaminophen, antihistamines).
* Genetic polymorphism of the CYP2D6 enzyme means some individuals ("poor metabolizers") are at significantly higher risk for adverse effects even at standard doses.
***
**Educational Disclaimer:** This information is for educational purposes only. Always consult the most recent product monograph, local institutional protocols, or clinical decision support tools (e.g., Lexicomp, UpToDate) before prescribing or administering medication.
