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Dextromethorphan / Promethazine Dosage

Medically reviewed by Drugs.com. Last updated on Aug 11, 2023.

Applies to the following strengths: 15 mg-6.25 mg/5 mL

Usual Adult Dose for Allergic Rhinitis

5 mL orally every 4 to 6 hours
Maximum dose: 30 mL in 24 hours (promethazine 37.5 mg; dextromethorphan 90 mg)

Comments:


Use: For the temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold.

Usual Adult Dose for Cold Symptoms

5 mL orally every 4 to 6 hours
Maximum dose: 30 mL in 24 hours (promethazine 37.5 mg; dextromethorphan 90 mg)

Comments:


Use: For the temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold.

Usual Adult Dose for Cough

5 mL orally every 4 to 6 hours
Maximum dose: 30 mL in 24 hours (promethazine 37.5 mg; dextromethorphan 90 mg)

Comments:


Use: For the temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold.

Usual Pediatric Dose for Allergic Rhinitis

Less than 2 years: Contraindicated

2 years to less than 6 years: 1.25 to 2.5 mL orally every 4 to 6 hours
Maximum dose: 10 mL in 24 hours (promethazine 12.5 mg; dextromethorphan 30 mg)

6 years to less than 12 years: 2.5 to 5 mL orally every 4 to 6 hours
Maximum dose: 20 mL in 24 hours (promethazine 25 mg; dextromethorphan 60 mg)

12 years to 18 years: 5 mL orally every 4 to 6 hours
Maximum dose: 30 mL in 24 hours (promethazine 37.5 mg; dextromethorphan 90 mg)

Comments:


Use: For the temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold.

Usual Pediatric Dose for Cold Symptoms

Less than 2 years: Contraindicated

2 years to less than 6 years: 1.25 to 2.5 mL orally every 4 to 6 hours
Maximum dose: 10 mL in 24 hours (promethazine 12.5 mg; dextromethorphan 30 mg)

6 years to less than 12 years: 2.5 to 5 mL orally every 4 to 6 hours
Maximum dose: 20 mL in 24 hours (promethazine 25 mg; dextromethorphan 60 mg)

12 years to 18 years: 5 mL orally every 4 to 6 hours
Maximum dose: 30 mL in 24 hours (promethazine 37.5 mg; dextromethorphan 90 mg)

Comments:


Use: For the temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold.

Usual Pediatric Dose for Cough

Less than 2 years: Contraindicated

2 years to less than 6 years: 1.25 to 2.5 mL orally every 4 to 6 hours
Maximum dose: 10 mL in 24 hours (promethazine 12.5 mg; dextromethorphan 30 mg)

6 years to less than 12 years: 2.5 to 5 mL orally every 4 to 6 hours
Maximum dose: 20 mL in 24 hours (promethazine 25 mg; dextromethorphan 60 mg)

12 years to 18 years: 5 mL orally every 4 to 6 hours
Maximum dose: 30 mL in 24 hours (promethazine 37.5 mg; dextromethorphan 90 mg)

Comments:


Use: For the temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold.

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Use with caution

Dose Adjustments

Elderly: Dose selection should be cautious, usually starting the low end of the dosing range.

Precautions

US BOXED WARNING: POTENTIALLY FATAL RESPIRATORY DEPRESSION IN CHILDREN LESS THAN 2 YEARS OF AGE:


Safety and efficacy have not been established in patients younger than 2 years.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:


Storage requirements:

General:

Monitoring:

Patient advice:

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.