Guaifenesin Dosage Recommendations for Adults and Children
The recommended dose of guaifenesin for adults and children 12 years and over is 200-400 mg (10-20 mL or 2-4 teaspoonfuls) every 4 hours, not to exceed 6 doses (2400 mg) in a 24-hour period. 1
Adult Dosing
- Adults and children 12 years and older:
- 200-400 mg (10-20 mL or 2-4 teaspoonfuls) every 4 hours
- Maximum: 2400 mg per day (6 doses in 24 hours)
- Extended-release formulation: 1200 mg (two 600 mg tablets) every 12 hours 2
Pediatric Dosing
Children 6 to under 12 years:
- 100-200 mg (5-10 mL or 1-2 teaspoonfuls) every 4 hours
- Maximum: 1200 mg per day (6 doses in 24 hours) 1
Children 2 to under 6 years:
- 50-100 mg (2.5-5 mL or ½-1 teaspoonful) every 4 hours
- Maximum: 600 mg per day (6 doses in 24 hours) 1
Children under 2 years:
- Consult a physician before use 1
Formulations Available
Guaifenesin is available in multiple formulations:
- Immediate-release liquid
- Immediate-release tablets (typically 200 mg)
- Extended-release tablets (600 mg)
- Combination products with other medications (decongestants, antihistamines, etc.)
Clinical Considerations
Mechanism of Action
Guaifenesin acts as an expectorant by loosening mucus in the airways and making coughs more productive. It helps relieve chest congestion by reducing the viscosity of secretions and promoting mucus clearance 3.
Efficacy
- Most effective for conditions with mucus hypersecretion, including acute upper respiratory tract infections and chronic bronchitis 3
- Has been shown to inhibit cough reflex sensitivity in patients with upper respiratory tract infections 4
Administration Guidelines
- For immediate-release formulations, multiple daily doses are needed to maintain 24-hour therapeutic effect
- Extended-release formulations offer the convenience of 12-hour dosing 5, 2
- Can be taken with or without food
Safety Profile
- Guaifenesin has a well-established safety profile in both adult and pediatric populations 3
- Most common adverse effects are mild and include:
- Gastrointestinal disturbances (nausea, stomach pain)
- Dizziness or headache
- Rash (rare)
Precautions
- Avoid excessive dosing; extremely high doses have been associated with central nervous system depression in rare cases 6
- Patients with persistent cough lasting more than 7 days, cough accompanied by fever, or cough producing excessive phlegm should consult a healthcare provider
Special Populations
- Pregnancy: Limited data available; consult healthcare provider
- Breastfeeding: Limited data available; consult healthcare provider
- Renal/Hepatic Impairment: No specific dosage adjustments recommended, but use with caution
Guaifenesin is generally considered safe and effective when used as directed for the temporary relief of chest congestion and productive cough. For symptoms that persist beyond 7 days or are accompanied by fever, consult a healthcare provider.