Guaifenesin Dosage for Chest Congestion
The recommended dosage of guaifenesin for relieving chest congestion is 200-400 mg every 4 hours (up to 2400 mg daily) for immediate-release formulations, or 600-1200 mg every 12 hours for extended-release formulations. 1, 2
Formulations and Dosing Options
Immediate-Release Formulations
- Adults and children 12 years and older: 200-400 mg every 4 hours, not to exceed 2400 mg in 24 hours
- Children 6-11 years: 100-200 mg every 4 hours, not to exceed 1200 mg in 24 hours
- Available as: Oral solution (100 mg/5 mL) 1
Extended-Release Formulations
- Adults and children 12 years and older: 600-1200 mg every 12 hours
- Provides convenience with 12-hour dosing compared to 4-hour dosing with immediate-release products 3, 2
Mechanism of Action and Efficacy
Guaifenesin works as an expectorant by:
- Loosening mucus in the airways
- Making coughs more productive
- Improving mucociliary clearance
- Relieving chest congestion associated with upper respiratory tract infections 2
It remains the only legally marketed expectorant in the US according to the OTC Monograph 2.
Clinical Applications
Guaifenesin is indicated for:
- Relief of chest congestion and wet cough due to common cold
- Secondary indication for use in stable chronic bronchitis (professional indication)
- May have utility in conditions where mucus hypersecretion is prevalent, including acute upper respiratory tract infections and possibly rhinosinusitis 2
Safety Profile
Guaifenesin has a well-established safety profile:
- Generally well-tolerated in both adult and pediatric populations
- Most common adverse events are mild and include gastrointestinal effects, nervous system effects, and skin reactions 4
- No serious adverse events have been reported in clinical studies 4
Important Considerations
- Multiple daily doses are needed to maintain 24-hour therapeutic effect with immediate-release formulations
- Extended-release formulations provide more convenient dosing (every 12 hours)
- Therapeutic plasma concentrations must be maintained for efficacy 3, 2
- Food may delay the time to maximum concentration (Tmax) but does not affect overall bioavailability 3
Cautions
- While generally safe, extremely high doses can potentially cause central nervous system depression in rare cases 5
- Should be used as directed and not exceed recommended dosages
- Consult a healthcare provider if symptoms persist beyond 7 days
Guaifenesin is considered safe and effective for the symptomatic treatment of chest congestion when used as directed, with extended-release formulations offering the convenience of less frequent dosing while maintaining therapeutic efficacy.