Cough Suppression Guidelines

Introduction to Dextromethorphan

The American Thoracic Society recommends dextromethorphan for cough suppression in adults and children ≥12 years, with a standard adult dosing of 10-30 mg every 4-6 hours, not to exceed 120 mg in 24 hours 1
Dextromethorphan has been shown to suppress cough in chronic bronchitis by 40-60%, but has limited efficacy (<20% suppression) in cough due to upper respiratory infections 1
Maximum cough reflex suppression occurs at 60 mg and can be prolonged, though most OTC preparations contain lower doses 2

For adults and children ≥12 years, the recommended dose is 10-30 mg every 4-6 hours, not to exceed 120 mg in 24 hours 1
For children 6-12 years, the recommended dose is 5-10 mg every 4 hours or 15 mg every 6-8 hours, not to exceed 60 mg in 24 hours 2
The extended-release formulation can be given as 10 mL (30 mg) every 12 hours, not to exceed 20 mL in 24 hours for adults and children ≥12 years 2

Use caution when combining dextromethorphan with serotonergic medications due to the risk of serotonin syndrome 3
Probenecid increases dextromethorphan levels, and MAO inhibitors are contraindicated 3

Dextromethorphan is generally preferred over codeine for cough suppression due to its better safety profile and non-narcotic status 2
Dextromethorphan has similar efficacy to codeine at standard doses, but with fewer side effects 2