Generic & Brand Names
Generic: Guaifenesin
Common Brands: Robitussin®, Benylin Expectorant®, Mucinex® (ER)
Drug Class
Expectorant Respiratory Agent Mechanism of Action
Guaifenesin increases the volume and reduces the viscosity of respiratory tract secretions, facilitating mucus clearance and making coughs more productive.
Indications
- Productive (wet) cough
- Chest congestion associated with upper respiratory tract infections
- Adjunct in acute bronchitis
Dosage (General)
- Adults: 200–400 mg every 4 hours (max 2.4 g/day)
- Extended-release (adults): 600–1200 mg every 12 hours
- Children 6–12 years: 100–200 mg every 4 hours
- Children <6 years: Use only if prescribed
Encourage adequate fluid intake.
Side Effects
- Nausea
- Vomiting
- Dizziness
- Headache
- Gastrointestinal discomfort
Contraindications & Precautions
- Hypersensitivity to guaifenesin
- Persistent or chronic cough (evaluate underlying cause)
- Avoid prolonged use without medical advice
Drug Interactions
- No clinically significant interactions reported
- Often combined with antitussives or antihistamines
Pregnancy & Lactation
Generally considered low risk. Use only if clearly needed.
Key Notes
- Best for wet, productive cough
- Not a cough suppressant
- Hydration improves effectiveness
References
- British National Formulary for Children (BNFc). Expectorants – Guaifenesin.
- Kliegman RM, St. Geme JW. Nelson Textbook of Pediatrics, 22nd ed. Elsevier; Cough and cold preparations.
- Katzung BG, Trevor AJ. Basic & Clinical Pharmacology, 15th ed. McGraw-Hill; Drugs affecting the respiratory system.
- Manufacturer prescribing information.