Skip to main content

Dextromethorphan

 

1. Generic Name & Brand Names

  • Generic Name: Dextromethorphan HBr

  • Common Brands:

    • Robitussin® DM

    • Delsym® (extended-release)

    • Vicks® DayQuil Cough

    • Theraflu® Cough Relief

    • Generic/store brands ("Tussin", "Cough Suppressant")

2. Dosage Forms

  • Oral:

    • Syrup (3-15 mg/5mL)

    • Extended-release suspension (30 mg/5mL)

    • Gel capsules (15-30 mg)

    • Lozenges/sprays

  • Combination Products:

    • With guaifenesin (Mucinex DM®)

    • With antihistamines (NyQuil®)

3. Drug Class

  • NMDA Receptor Antagonist

  • Sigma-1 receptor agonist

  • Centrally-acting antitussive (cough suppressant)

  • Not an analgesic or expectorant

4. Uses

  • Symptomatic Relief of Non-Productive Cough:

    • Common cold, bronchitis, throat irritation

  • Off-label/Investigational:

    • Treatment-resistant depression (with bupropion: Auvelity®)

    • Neuropathic pain

    • Pseudobulbar affect

5. Side Effects

Common (≥5%)Serious (Discontinue Immediately)
DrowsinessSerotonin Syndrome
DizzinessRespiratory Depression (high doses)
NauseaBradycardia
At High Doses:Dissociative Hallucinations
• ConfusionSeizures
• AtaxiaAcute Liver Injury (APAP combos)

6. Critical Warnings

  • 🚫 Contraindications:

    • MAOI use (risk of fatal serotonin toxicity)

    • Asthma/chronic bronchitis with productive cough

  • Black Box Warning (Combination Products):

    • Acetaminophen overdose risk in multi-symptom formulations

  • Abuse Potential:

    • "Robotripping" - recreational use causes dissociative effects at 5-10x doses

    • Schedule V controlled substance in some states

  • Drug Interactions:

    • ⚠️ SSRIs/SNRIs: Serotonin syndrome (agitation, hyperthermia)

    • ⚠️ Quinidine: ↑ DXM levels 20-fold (CYP2D6 inhibition)

7. How to Take

FormAdults (Max Daily)Children (6-12 yrs)
Immediate-Release10-30 mg q4-8h (120 mg)5-15 mg q4-8h (60 mg)
Extended-Release60 mg q12h (120 mg)30 mg q12h (60 mg)

  • Key Rules:

    • Use lowest effective dose for ≤7 days

    • Never combine with alcohol

    • Avoid in children <6 years (AAP recommendation)

8. Toxicity & Overdose

Dose RangeEffects
100-200 mgEuphoria, nystagmus
200-500 mgDissociation, hallucinations
>500 mgComa, respiratory failure

  • Management:

    • Naloxone ineffective (non-opioid mechanism)

    • Activated charcoal + benzodiazepines for seizures

9. Abuse Deterrence

  • "Robotripping" Risks:

    • Hypertension, hyperthermia, brain damage

    • Common in adolescents (easy OTC access)

  • High-Risk Formulations:

    • Alcohol-containing syrups (up to 10% ethanol)

    • Coricidin® ("Triple C") - antihistamine combo causes tachycardia

10. Storage & Safety

  • Lock Away: High abuse potential - keep in secure cabinet

  • Check Combo Products: Many contain acetaminophen (liver risk)

  • Disposal: Use drug take-back programs

Clinical Alternatives for Dry Cough

DrugAdvantageRisk Profile
HoneySafe for >1 year oldNone
PholcodineLess abuse potentialDrowsiness (EU/Asia only)
CodeinePrescription-onlyAddiction/respiratory depression

Critical Safety Alerts

⚠️ Serotonin Syndrome Risk:

  • Fatal cases reported with SSRIs (e.g., fluoxetine) - require 2-week washout.
    ⚠️ Pediatric Mortality:

  • Avoid under age 6 - no proven efficacy and high overdose risk.
    ⚠️ "DXM Calculator" Danger:

  • Online calculators promote recreational dosing - educate teens/parents.

Dextromethorphan vs. Codeine

ParameterDextromethorphanCodeine
MechanismNMDA antagonistμ-opioid agonist
Addiction RiskModerate (high dose)High
CNS DepressionLow (therapeutic dose)Significant
OTC StatusYesPrescription-only

Professional Guidance

✅ Appropriate Use:

  • Short-term suppression of non-productive cough in adults

  • Delsym® for nighttime cough (12-hour duration)
    ❌ Avoid When:

  • Productive cough (retains infection)

  • Asthma/COPD exacerbations

  • With MAOIs/SSRIs/sibutramine
    💡 Pro Tip:

For viral cough: honey (10g) > DXM for efficacy/safety in children (Pediatrics).

📊 Efficacy Note:

  • 30 mg DXM reduces cough frequency by 25-40% vs. placebo (Cochrane Review).

  • No benefit over placebo in children under 12 (BMJ).

Comments

Post a Comment

Popular posts from this blog

First-Year BPT Study Guide: Units 1 to 4 Explained for Physiotherapy Students

  🔹 Introduction Starting your Bachelor of Physiotherapy (BPT) journey? The first year lays the essential groundwork for becoming a skilled physiotherapist. This blog explains the first-year BPT Units 1 to 4—key concepts that cover physiotherapy basics, anatomy, physiology, and professional ethics. Whether you're studying for exams or building your foundation, these insights are crucial for academic and clinical success. 🔹 Unit 1: Introduction to Physiotherapy Keywords: introduction to physiotherapy, first-year physiotherapy course, BPT basics In this unit, students explore the history, scope, and branches of physiotherapy. From treating joint pain to supporting neurological rehabilitation, physiotherapy offers diverse career opportunities. The profession originated in ancient times and gained formal recognition during wartime rehabilitation. Specialties include: Orthopedic physiotherapy Neurological physiotherapy Pediatric physiotherapy Cardiopulmonary physiot...
Post a Comment
Read more

⚠️ Contraindications of Electrotherapy Modalities: Learn Fast

  Electrotherapy is a powerful tool in physiotherapy — but using it safely is just as important as using it effectively. Here's a fast-track guide to the contraindications of common electrotherapy modalities for students, interns, and clinicians. 🚫 What Are Contraindications? These are conditions or situations where electrotherapy should NOT be used due to risk of harm or complications. ⚡ Common Electrotherapy Modalities & Their Contraindications 🔌 1. TENS (Transcutaneous Electrical Nerve Stimulation) Avoid if: Patient has a pacemaker or implantable defibrillator Over pregnant abdomen or uterus Over malignant tumors Broken, infected, or anesthetic skin On carotid sinus area (risk of cardiac reflex) Epileptic patients (caution advised) 🔄 2. IFT (Interferential Therapy) Avoid if: Metal implants in the treatment area Open wounds or skin conditions Pregnancy (especially lower abdomen/lumbar) Over the eyes, carotid sinus, or chest...
Post a Comment
Read more

Metoprolol – heart rate control

  1.  Mechanism & Class Class:  β₁-Selective Beta-Blocker ( Cardioselective ) Action: Blocks cardiac β₁-receptors → ↓  sinus node firing rate  and  AV conduction Reduces resting/peak heart rate (HR), myocardial oxygen demand Formulations: Tartrate (IR):  Short-acting (dosed BID) -  Lopressor® Succinate (ER):  24-hour control -  Toprol-XL® 2.  Key Indications for Rate Control Condition Target HR Formulation Atrial Fibrillation (AFib) 60-100 bpm Tartrate BID Sinus Tachycardia 60-100 bpm Succinate daily Post-MI Tachycardia 50-60 bpm Tartrate BID → Succinate SVT Acute IV → PO IV/PO Tartrate 3.  Dosing Protocols Scenario Initial Dose Titration Max Dose Chronic AFib Tartrate 25 mg BID ↑ by 25 mg BID q3-7d 100 mg BID Acute SVT/AFib (IV) 2.5-5 mg IV slow Repeat q5min × 3 15 mg Post-MI Tartrate 25 mg BID → Switch to Succinate 100 mg daily 200 mg/day Anxiety-Induced Tachycardia Succinate 25 mg daily ↑ 25 mg weekly 200 mg/day Goal HR:...
Post a Comment
Read more