Robitussin (Dextromethorphan) 10 mg Dosing
For adults and children 12 years and older, the proper dose of dextromethorphan is 10 mL (containing 10 mg) every 12 hours, not exceeding 20 mL in 24 hours. 1
Age-Based Dosing Guidelines
The FDA-approved dosing for dextromethorphan follows strict age-based parameters rather than weight-based calculations 1:
Adults and Adolescents (≥12 years)
- 10 mL every 12 hours
- Maximum: 20 mL in 24 hours 1
Children 6 to under 12 years
- 5 mL every 12 hours
- Maximum: 10 mL in 24 hours 1
Children 4 to under 6 years
- 2.5 mL every 12 hours
- Maximum: 5 mL in 24 hours 1
Children under 4 years
- Do not use 1
Important Administration Details
The medication must be measured only with the dosing cup provided with the product and this cup should not be used with other medications. 1 The bottle should be shaken well before each use. 1
Pediatric Considerations and Limitations
The American Academy of Pediatrics notably does not include specific dextromethorphan dosing recommendations in their drug formularies, reflecting ongoing concerns about its use in children. 2 When prescribing for pediatric patients, weight-based and age-specific factors require careful consideration, and consultation with current product labeling or a pediatric pharmacist is recommended. 2
Clinical Context
While dextromethorphan has been used for over 30 years as a cough suppressant, its efficacy for acute cough remains uncertain and is not strongly supported by pediatric guidelines. 3 The age-based dosing (rather than weight-based) results in substantial variability in the relative amount of drug administered per kilogram of body weight. 3
Research suggests that doses around 0.5 mg/kg may provide better symptomatic relief while balancing adverse events, though the standard FDA-approved age-based dosing remains the recommended approach for clinical practice. 3
Safety Profile
Adverse reactions are generally infrequent and not severe when used at recommended doses, with predominant symptoms being dose-related neurological, cardiovascular, and gastrointestinal disturbances. 4 The most significant safety concern is abuse potential at supratherapeutic doses, where dextromethorphan can produce dissociative effects similar to ketamine. 5