Is Disudrin (dextromethorphan) syrup suitable for a 5-year-old, 21kg male patient?

Dextromethorphan Syrup for a 5-Year-Old Child

Dextromethorphan syrup is appropriate for this 5-year-old, 21kg patient at a dose of 2.5 mL every 12 hours, not exceeding 5 mL in 24 hours, based on FDA-approved dosing guidelines. 1

FDA-Approved Dosing for This Age Group

For children 4 to under 6 years of age, the approved dosing is:

• 2.5 mL every 12 hours
• Maximum: 5 mL in 24 hours 1

This patient at 5 years old and 21kg falls squarely within this dosing category. The FDA label explicitly provides dosing for this age range, making it suitable for use. 1

Safety Profile in Pediatric Patients

Dextromethorphan has a reassuring safety profile when used at therapeutic doses in children. 2

Key safety considerations include:

• Adverse events are infrequent and usually not severe at therapeutic doses 2
• The most significant safety concern identified through surveillance is abuse/overdose, not therapeutic use 2, 3
• In a large surveillance study of 1,716 pediatric cases with adverse events, only 3% followed therapeutic dosing—78% involved overdose 3
• No deaths occurred in children following dextromethorphan-only ingestions in multifaceted surveillance programs 3

Common Adverse Effects at Therapeutic Doses

When adverse reactions occur, they are typically:

• Dose-related neurological symptoms (ataxia, drowsiness) 2, 3
• Cardiovascular effects (mild tachycardia) 2, 3
• Gastrointestinal disturbances (nausea) 2
• Flushing or urticarial rash (occurred in 18.1% of overdose cases, less common at therapeutic doses) 3

Critical Safety Warnings

Do not use dextromethorphan if the child is taking monoamine oxidase inhibitors (MAOIs)—this represents the most significant drug interaction concern. 2

Additional precautions:

• Ensure supervised administration to prevent accidental overdose, as 69% of adverse events involved unsupervised self-administration 3
• Use only the dosing cup provided with the product 1
• Shake bottle well before each use 1

Duration of Use

Dextromethorphan should be used for short-term treatment only. 2 If cough persists beyond 7 days or worsens, reevaluation is warranted to identify underlying causes requiring different management.

When NOT to Use Dextromethorphan

Avoid dextromethorphan in:

• Children under 4 years of age (per FDA labeling) 1
• Patients taking MAOIs 2
• Situations where cough serves a protective function (e.g., productive cough clearing secretions)