What is the maximum recommended dose of extended release Mucinex (Guaifenesin)?

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Last updated: July 26, 2025View editorial policy

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Maximum Recommended Dose of Extended Release Mucinex (Guaifenesin)

The maximum recommended dose of extended release Mucinex (guaifenesin) is 2400 mg per day, taken as 1200 mg (2 tablets of 600 mg) every 12 hours.

Dosage Information

Extended release Mucinex (guaifenesin) is available as:

  • 600 mg extended-release tablets
  • Recommended adult dosing: 1200 mg (2 tablets) every 12 hours
  • Maximum daily dose: 2400 mg per day

Clinical Considerations

Mechanism of Action

Guaifenesin works as an expectorant by:

  • Loosening mucus in the airways
  • Making coughs more productive
  • Thinning bronchial secretions
  • Facilitating the removal of mucus from the respiratory tract

Clinical Efficacy

  • Guaifenesin is the only FDA-approved over-the-counter expectorant in the United States 1
  • Most effective in conditions where mucus hypersecretion is prevalent:
    • Acute upper respiratory tract infections
    • Chronic bronchitis
    • Possibly rhinosinusitis

Safety Profile

Guaifenesin has a well-established safety profile when used as directed:

  • Common side effects (generally mild):

    • Nausea
    • Gastrointestinal discomfort
    • Drowsiness
  • Serious adverse effects are rare with therapeutic doses, but can include:

    • Kidney stones (with prolonged high-dose use)
    • Potential CNS depression at extremely high doses 2

Special Populations and Considerations

Renal/Hepatic Impairment

  • No specific dosage adjustments are recommended in the product labeling
  • However, caution is advised in patients with significant renal or hepatic dysfunction

Pregnancy and Lactation

  • Limited data available on safety during pregnancy
  • Use only if potential benefits outweigh risks

Important Warnings

Overdose Risk

  • Extremely high doses of guaifenesin have been associated with CNS depression 2
  • A case report documented asystole following massive guaifenesin overdose 2

Efficacy Limitations

  • A study examining a single 1200 mg dose of extended-release guaifenesin showed no significant effect on mucociliary clearance or cough clearance compared to placebo in patients with acute respiratory tract infections 3
  • Multiple daily doses may be needed to maintain therapeutic effect 1

Duration of Use

  • If symptoms persist beyond 7 days or are accompanied by fever, consult a healthcare provider
  • Extended-release formulations provide 12-hour dosing convenience compared to immediate-release products that require more frequent administration 1

Conclusion

When using extended-release Mucinex (guaifenesin), adhere to the maximum recommended dose of 2400 mg per day (1200 mg every 12 hours) to ensure safety while maximizing potential therapeutic benefits.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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