Guaifenesin (Mucinex) Dosing Recommendations
The recommended adult dosage of guaifenesin is 200-400 mg every 4 hours or 600-1200 mg every 12 hours (extended-release formulation), not to exceed 2400 mg per day. 1
Adult Dosing
Immediate-Release Formulation
- 200-400 mg every 4 hours as needed
- Maximum daily dose: 2400 mg
- Available as 200 mg and 400 mg tablets or 100 mg/5 mL oral solution 2
Extended-Release Formulation
- 600-1200 mg every 12 hours
- Maximum daily dose: 2400 mg
- Available as 600 mg and 1200 mg extended-release tablets 3
- Provides convenience with twice-daily dosing compared to every 4 hours with immediate-release formulations
Pediatric Dosing
Children's dosing is weight-based:
- Maximum daily dose: 15-20 mg/kg per day (not to exceed 1.0 g/day) 1
- For liquid formulations: 100 mg/5 mL concentration is commonly available 2
Age-specific recommendations:
- Children 2-5 years: 50-100 mg every 4 hours (immediate-release)
- Children 6-11 years: 100-200 mg every 4 hours (immediate-release)
- Children 12 years and older: Adult dosing
Clinical Considerations
- Guaifenesin is an expectorant that helps loosen mucus in the airways, making coughs more productive 4
- It is indicated for relief of chest congestion and wet cough due to common cold and stable chronic bronchitis
- Extended-release formulations maintain therapeutic effect for 12 hours, improving compliance compared to immediate-release formulations that require dosing every 4 hours 3
Safety Profile
- Guaifenesin has a well-established safety profile when used at recommended doses 1
- Common side effects are mild and may include:
- Gastrointestinal disturbances (most common)
- Dizziness
- Headache
- Rash (uncommon)
- A 2019 study confirmed that extended-release guaifenesin was well-tolerated with only mild adverse events reported 5
Important Considerations
- Take with adequate fluid to help loosen mucus
- Extended-release tablets should be swallowed whole, not crushed or chewed
- Despite widespread use, evidence for clinical efficacy is stronger in chronic respiratory conditions than in acute upper respiratory infections 4, 6
- No significant drug interactions of clinical importance have been reported
When selecting between immediate-release and extended-release formulations, consider patient preference for dosing frequency and convenience, as both provide equivalent systemic exposure when administered at appropriate intervals 3.