Mucinex (Guaifenesin) Dosing Guidelines
Standard Adult Dosing
For adults, the recommended dose of immediate-release guaifenesin is 200-400 mg every 4 hours, up to 6 times daily (maximum 2400 mg/day), while extended-release formulations are dosed at 600-1200 mg every 12 hours. 1
Immediate-Release Formulations
- Adults: 200-400 mg orally every 4 hours 1
- Maximum daily dose: 2400 mg (six 400 mg doses) 1
- Multiple daily doses required to maintain 24-hour therapeutic effect 1
- Flexible dose titration allows adjustment to increase plasma concentrations as needed 1
Extended-Release Formulations
- Adults: 600-1200 mg orally every 12 hours 2, 3
- The 1200 mg dose (two 600 mg tablets) every 12 hours is commonly used for acute upper respiratory tract infections 3
- Steady-state exposures are equivalent between extended-release dosed every 12 hours and immediate-release dosed every 4 hours 2
- Extended-release provides convenience with twice-daily dosing compared to immediate-release formulations 1
Pediatric Dosing
Children Aged 4-11 Years
- Dose range: 100-200 mg every 4 hours for immediate-release formulations 4
- Maximum daily dose varies by age and formulation 4
- Age-based dosing of 100-400 mg has been studied in children aged 2-17 years 4
- When comparing the upper dose for children aged 2-11 years with the lower dose for adolescents aged 12-17 years, similar systemic exposure is observed 4
Adolescents (12 Years and Older)
- Dosing: Follow adult dosing recommendations 4
- Area under the curve and maximum plasma concentration both increase with age when using the upper recommended monograph dose 4
- Oral clearance and volume of distribution increase with age due to increasing body size 4
Important Pediatric Considerations
- Allometric scaling indicates no maturation-related changes in clearance or volume of distribution beyond body size 4
- Terminal half-life increases with age due to larger increases in volume of distribution compared to clearance 4
- Dosing should be administered 2 hours after meals based on pharmacokinetic studies 4
Special Populations
Elderly Patients
- No specific dose adjustment is mentioned in the available evidence for elderly patients 1
- Standard adult dosing appears appropriate, though the flexible dosing range (200-400 mg every 4 hours) allows for individualized titration 1
Renal Impairment
- No specific dosing adjustments for renal impairment are provided in the available evidence 1
- Guaifenesin pharmacokinetics have not been specifically studied in patients with renal dysfunction in the provided literature
Hepatic Impairment
- No specific dosing adjustments for hepatic impairment are documented in the available evidence 1
- No hepatic metabolism considerations are mentioned in the clinical studies reviewed
Food Effects and Administration
Extended-Release Formulations
- Food affects the rate but not extent of absorption 2
- AUC and maximum concentration are equivalent between fasted and fed states for the 1200 mg extended-release dose 2
- Time to maximum concentration is delayed in the fed state compared to fasted state 2
- Can be administered without regard to meals, though timing may affect symptom relief onset 2
Clinical Efficacy Timing
- Most prominent treatment differences appear by Day 4 of therapy 5
- Seven-day treatment courses are commonly studied for acute upper respiratory tract infections 3, 5
Safety and Tolerability
Adverse Events
- Guaifenesin has a well-established and favorable safety profile in both adult and pediatric populations 1
- In a study of 552 adults, only 28 patients (5.1%) experienced treatment-emergent adverse events, all mild in severity 3
- Most common adverse events include gastrointestinal symptoms (n=11), nervous system effects (n=8), and psychiatric symptoms (n=3) 3
- No serious adverse events or deaths occurred in post-marketing surveillance 3