Guaifenesin
MUCINEX
Pronunciation: gwye-FEN-e-sin
“Mucin, next Guy fencin’”
What it isExpectorant with incidental NMDA antagonism and an otherwise uncertain target; cough with thick secretions.
Why this oneIt is the only widely used oral expectorant, but its popularity greatly exceeds the strength of its evidence.
What limits itBenefit is often indistinguishable from hydration; stop if there is no clear response rather than escalating combination products.
FDA-approved for
- cough (expectorant) (~1952)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Expectorant (OTC Uses): helps loosen phlegm (mucus) and thin bronchial secretions to rid the bronchial passageways of bothersome mucus and make coughs more productive | Adults and children >=12 y | 1-2 tablets (600-1,200 mg ER) q12h | 1-2 tablets (600-1,200 mg ER) q12h | 4 tablets (2,400 mg) per 24 h |
| Expectorant (OTC Uses): helps loosen phlegm (mucus) and thin bronchial secretions to rid the bronchial passageways of bothersome mucus and make coughs more productive | Children <12 y | Do not use | Do not use | Do not use |
Renal Undefined
Hepatic Undefined
Do not exceed 4 tablets in 24 hours.
Instructions
- Do not crush, chew, or break the tablet.
- Take with a full glass of water.
- May be taken without regard to the timing of meals.
- Do not use in children under 12 years.
Available strengths
- ER tab 600, 1200 mg
- tab 200, 400, 600, 1200 mg
- sol 200, 400 mg/10 mL
- sol 300 mg/15 mL
- sol 50 mg/2.5 mL
- sol 100 mg/5 mL
Pregnancy Undefined
Lactation Undefined
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 600 mg | ER tab | 60 BID | $17.04 | out of stock |
| 1200 mg | ER tab | 60 BID | $25.90 | not offered |
Generic entryPre-1982
NO BOXED WARNINGS
Principal riskLittle
Classes and tags
Clinical profile
Legacy pregnancy categoryNot assigned — OTC/monograph
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.