Proper Dosing for Syrup Looz (Dextromethorphan)
The proper dosing for Syrup Looz (dextromethorphan) is 10 mL every 12 hours for adults and children 12 years and older (not exceeding 20 mL in 24 hours), 5 mL every 12 hours for children 6-11 years (not exceeding 10 mL in 24 hours), and 2.5 mL every 12 hours for children 4-5 years (not exceeding 5 mL in 24 hours). 1
Age-Based Dosing Algorithm
The FDA-approved dosing for dextromethorphan syrup follows a clear age-based algorithm:
Adults and children ≥12 years:
- 10 mL every 12 hours
- Maximum: 20 mL in 24 hours
Children 6 to <12 years:
- 5 mL every 12 hours
- Maximum: 10 mL in 24 hours
Children 4 to <6 years:
- 2.5 mL every 12 hours
- Maximum: 5 mL in 24 hours
Children <4 years:
- Do not use 1
Administration Guidelines
When prescribing Syrup Looz (dextromethorphan), follow these important administration guidelines:
- Shake the bottle well before use
- Measure only with the dosing cup provided with the medication
- Do not use the dosing cup with other products
- Administer as directed or as prescribed by a doctor 1
Clinical Efficacy and Considerations
While dextromethorphan is one of the most widely used antitussives for cough associated with acute upper respiratory tract infection, research shows limited evidence supporting its efficacy. A study examining a single 30 mg dose showed minimal clinical benefit compared to placebo in treating cough associated with acute upper respiratory tract infections 2.
Safety Considerations
Mechanism of Action
Dextromethorphan works primarily through NMDA receptor antagonism, which underlies its efficacy in treating acute cough 3. At therapeutic doses, it does not possess the CNS pharmacology of opiates (no analgesia, respiratory depression, or abuse liability) 4.
Potential for Misuse
Be aware that at higher doses, dextromethorphan can cause psychoactive effects, making it potentially appealing for abuse 5. Patients should be counseled to strictly adhere to recommended dosing.
Drug Interactions
Genotypic variations in metabolizing enzymes and interactions with other drugs can result in large inter-individual variability in pharmacological and toxicological effects 5. Consider potential drug interactions when prescribing.
Common Pitfalls to Avoid
Improper measurement: Always emphasize the importance of using only the provided dosing cup for accurate measurement.
Exceeding recommended dosage: Clearly communicate the maximum daily dose to prevent toxicity.
Use in very young children: Reinforce that dextromethorphan is contraindicated in children under 4 years of age.
Extended use: Dextromethorphan should be used for the shortest duration possible to manage symptoms, as prolonged use may lead to tolerance.
Failure to recognize limited efficacy: Be aware that evidence supporting dextromethorphan's clinical efficacy is limited, and manage patient expectations accordingly.