Adult Starting Dosage for Guaifenesin 100mg/5ml
The recommended adult starting dosage for guaifenesin 100mg/5ml is 200-400 mg (10-20 ml) every 4 hours, not to exceed 2400 mg (120 ml) in 24 hours.
Dosing Guidelines
Immediate-Release Formulation
- Guaifenesin 100mg/5ml liquid should be dosed at 200-400 mg (10-20 ml) every 4 hours 1
- Maximum daily dose should not exceed 2400 mg (120 ml) in 24 hours 1
- Multiple daily doses are required to maintain therapeutic effect throughout the day due to guaifenesin's short half-life 1, 2
Extended-Release Formulation Alternative
- If considering extended-release tablets instead of liquid, the dosage is 600-1200 mg every 12 hours 2
- Extended-release formulation provides convenience with twice-daily dosing compared to the every 4-hour dosing of immediate-release formulations 2, 3
Clinical Considerations
Mechanism of Action
- Guaifenesin acts by loosening mucus in the airways and making coughs more productive 1
- It is indicated for relief of wet cough and chest congestion due to common cold and as an expectorant in stable chronic bronchitis 1
Safety Profile
- Guaifenesin has a well-established and favorable safety profile in adult populations 1, 3
- Most common adverse effects are mild and include gastrointestinal disturbances, nervous system effects, and skin reactions 3
Efficacy
- Clinical efficacy has been demonstrated most widely in chronic respiratory conditions where excess mucus production and cough are more stable symptoms 1
- Studies show guaifenesin inhibits cough-reflex sensitivity in acute viral cough 4
Important Precautions
- Dose titration may be needed to achieve optimal therapeutic effect 1
- Although rare, high doses of guaifenesin have been associated with central nervous system depression in overdose cases 5
- For patients with persistent symptoms beyond 7 days, medical evaluation is recommended 3