What is the recommended daily dose of Copastin (dextromethorphan) tablets?

Copastin (Dextromethorphan) Dosing

For adults and children 12 years and older, the recommended dose of Copastin (dextromethorphan) is 10 mL every 12 hours, not exceeding 20 mL in 24 hours. 1

Adult Dosing (≥12 years)

• Standard dose: 10 mL every 12 hours 1
• Maximum daily dose: 20 mL in 24 hours 1
• Shake bottle well before each use and measure only with the provided dosing cup 1

Pediatric Dosing

Children 6 to under 12 years:

• 5 mL every 12 hours 1
• Maximum: 10 mL in 24 hours 1

Children 4 to under 6 years:

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

Children under 4 years:

• Do not use 1

Clinical Context

The 12-hour dosing interval reflects dextromethorphan's long terminal half-life, which allows for sustained antitussive effect with twice-daily administration 1. Research demonstrates that dextromethorphan at 20 mg doses effectively reduces both cough frequency and intensity, with a favorable safety profile compared to codeine 2. The medication is non-narcotic and has minimal side effects even at therapeutic doses 2.

Important Administration Guidelines

• Always use the dosing cup provided with the specific product 1
• Do not use the dosing cup with other medications 1
• Shake the bottle thoroughly before measuring each dose 1
• Follow the dosing schedule strictly—do not exceed the maximum daily dose 1