Guaifenesin (Monograph)

Brand names: Children’s Mucinex, Diabetic Tussin, Guiatuss, Mucinex
Drug class: Expectorants
VA class: RE516
CAS number: 93-14-1

Medically reviewed by Drugs.com on Jan 22, 2025. Written by ASHP.

Introduction

Expectorant.

Uses for Guaifenesin

Cough

Symptomatic management of productive cough to loosen and thin sputum and bronchial secretions and ease expectoration.

Improves cough symptoms associated with common cold, bronchitis, laryngitis, pharyngitis, pertussis, influenza, measles, and coughs provoked by chronic paranasal sinusitis.

May be useful in the management of irritative nonproductive cough and coughs productive of scanty amounts of thick, viscous secretions.

May indirectly diminish the tendency to cough, but mechanism of this effect differs from that of antitussives (which inhibit or suppress cough); insufficient evidence to support efficacy as antitussive.

Used in fixed combination with other agents (e.g., acetaminophen, chlorpheniramine, dextromethorphan, ephedrine, phenylephrine, pseudoephedrine) for the temporary relief of productive cough and/or other symptoms (nasal congestion, fever).

Guaifenesin Dosage and Administration

Administration

Administer orally.

Do not break, crush, or chew extended-release tablets.

Dosage

Because combinations and dosage strengths vary for fixed-combination preparations, consult manufacturer’s product labeling for appropriate dosage of the specific preparation.

Pediatric Patients

Cough

Oral

Children <2 years of age: Individualize dosage. (See Pediatric Use under Cautions.)

Children 2 to <6 years of age, conventional preparations: 50–100 mg every 4 hours, up to 600 mg daily. (See Pediatric Use under Cautions.)

Children 2–6 years of age, extended-release preparations: 300 mg every 12 hours, up to 600 mg daily. (See Pediatric Use under Cautions.)

Children 6 to <12 years of age, conventional preparations: 100–200 mg every 4 hours, up to 1.2 g daily.

Children 6–12 years of age, extended-release preparations: 600 mg every 12 hours, up to 1.2 g daily.

Children ≥12 years of age, conventional preparations: 200–400 mg every 4 hours, up to 2.4 g daily.

Children ≥12 years of age, 600-mg extended-release tablets: 600 mg or 1.2 g every 12 hours, up to 2.4 g daily.

Adults

Cough

Oral

Conventional preparations: 200–400 mg every 4 hours, up to 2.4 g daily.

600-mg extended-release tablets: 600 mg or 1.2 g every 12 hours, up to 2.4 g daily.

Prescribing Limits

Pediatric Patients

Cough

Oral

Children 2 to <6 years of age, conventional preparations: Maximum 600 mg daily.

Children 2–6 years of age, extended-release preparations: Maximum 600 mg daily.

Children 6 to <12 years of age, conventional preparations: Maximum 1.2 g daily.

Children 6–12 years of age, extended-release preparations: Maximum 1.2 g daily.

Children ≥12 years of age, conventional preparations: Maximum 2.4 g daily.

Children ≥12 years of age, extended-release preparations: Maximum 2.4 g daily.

Adults

Cough

Oral

Conventional preparations: Maximum 2.4 g daily.

Extended-release preparations: Maximum 2.4 g daily.

Cautions for Guaifenesin

Contraindications

Known hypersensitivity to guaifenesin.

Warnings/Precautions

General Precautions

Excessive Dosage

Emesis may result from doses larger than those required for expectorant action, but GI upset at ordinary dosage is rare.

Persistent Cough

Do not use as self-medication for persistent or chronic cough (e.g., that associated with smoking, asthma, chronic bronchitis, emphysema), or cough accompanied by excessive phlegm unless directed by a clinician.

Persistent cough may indicate serious condition; if it persists for >1 week, is recurrent, or is accompanied by fever, rash, or persistent headache, consult a clinician.

Use of Fixed Combinations

When used in fixed combination with other agents (e.g., acetaminophen, chlorpheniramine, codeine, dextromethorphan, ephedrine, phenylephrine, pseudoephedrine), consider the cautions, precautions, and contraindications associated with the concomitant agent(s).

Specific Populations

Pregnancy

Category C.

Lactation

Not known whether guaifenesin is distributed into milk.

Pediatric Use

Safety and efficacy of Mucinex 600-mg extended-release tablets not established in children <12 years of age.

Risk of overdosage and toxicity (including death) in children <2 years of age receiving OTC preparations containing antihistamines, cough suppressants, expectorants, and nasal decongestants alone or in combination for relief of symptoms of upper respiratory tract infection. Limited evidence of efficacy for these preparations in this age group; appropriate dosages not established. Therefore, FDA recommends not to use such preparations in children <2 years of age; safety and efficacy in older children under evaluation. Because children 2–3 years of age also are at increased risk of overdosage and toxicity, some manufacturers of oral nonprescription cough and cold preparations agreed to voluntarily revise the product labeling to state that such preparations should not be used in children <4 years of age. FDA recommends that parents and caregivers adhere to dosage instructions and warnings on the product labeling that accompanies the preparation and consult a clinician about any concerns. Clinicians should ask caregivers about use of OTC cough/cold preparations to avoid overdosage.

Stability

Storage

Tight containers.

Actions

Reduces the viscosity of tenacious secretions and acts as an expectorant by increasing respiratory tract fluid.
Increases expectorated sputum volume over the first 4–6 days of a productive cough, decreases sputum viscosity and difficulty in expectoration, and improves associated symptoms.

Advice to Patients

Importance of contacting a clinician if cough persists for >1 week, tends to recur, or is accompanied by fever, rash, or persistent headache.
Importance of not using for self-medication for persistent or chronic cough unless directed by a clinician.
Importance of keeping Mucinex 600-mg extended-release tablets out of reach of young children to avoid accidental swallowing and choking.
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs as well as any concomitant illnesses.
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.
Importance of informing patients of other important precautionary information. (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

guaiFENesin
Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Granules	50 mg per packet	Mucinex Mini Melts	Reckitt Benckiser
		100 mg per packet	Mucinex Mini Melts	Reckitt Benckiser
	Solution	100 mg/5 mL*	Children’s Mucinex Chest Congestion	Reckitt Benckiser
			Diabetic Tussin Expectorant	Health Care Products
			Guaifenesin Oral Solution
			Guiatuss Syrup	Goldline
		200 mg/5 mL	Diabetic Tussin Mucus Relief	Health Care Products
	Tablets	200 mg*	Guaifenesin Tablets
	Tablets, extended-release	600 mg	Mucinex	Reckitt Benckiser
		1.2 g	Mucinex Maximum Strength	Reckitt Benckiser

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

guaiFENesin and Codeine Phosphate
Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Solution	100 mg/5 mL Guaifenesin and Codeine Phosphate 10 mg/5 mL*	Cheratussin AC (C-V)	Qualitest
			Guaiatussin AC (C-V)	Hi-Tech
			Guaifenesin AC Cough Syrup (C-V)
			Guaifenesin and Codeine Phosphate Oral Solution (C-V)
			Robafen AC (C-V)	Major
		200 mg/5 mL Guaifenesin and Codeine Phosphate 8 mg/5 mL	Codar GF (C-V)	Respa

Other guaiFENesin Combinations
Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	For Solution	400 mg/packet with Acetaminophen 1 g/packet	Theraflu Flu & Chest Congestion	Novartis
		400 mg/packet with Acetaminophen 1 g/packet, Dextromethorphan Hydrobromide 30 mg/packet, and Pseudoephedrine Hydrochloride 60 mg/packet	Theraflu Max-D Severe Cold & Flu	Novartis
	Granules	50 mg per packet with Dextromethorphan Hydrobromide 5 mg/packet	Mucinex Cough Mini Melts	Reckitt Benckiser
	Solution	33.3 mg/5 mL with Dextromethorphan Hydrobromide 3.3 mg/5 mL	Vick’sNature Fusion Cough and Chest Congestion	Procter & Gamble
		50 mg/5 mL with Dextromethorphan Hydrobromide 5 mg/5 mL and Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Robitussin Cold & Cough CF	Pfizer
		50 mg/5 mL with Phenylephrine Hydrochloride 2.5 mg/5 mL	Triaminic Chest and Nasal Congestion	Novartis
		66.6 mg/5 mL with Acetaminophen 108.3 mg/5 mL, Dextromethorphan Hydrobromide 3.3 mg/5 mL, and Phenylephrine Hydrochloride 1.6 mg/5 mL	Tylenol Cold Multi-Symptom Severe	McNeil
			Tylenol Cold & Flu Severe	McNeil
		66.6 mg/5 mL with Acetaminophen 108.3 mg/5 mL, and Phenylephrine Hydrochloride 1.6 mg/5 mL	Theraflu Warming Relief Cold & Chest Congestion	Novartis
		66.6 mg/5 mL with Dextromethorphan Hydrobromide 3.3 mg/5 mL	Vick’s Dayquil Mucus Control DM	Procter & Gamble
		66.6 mg/5 mL with Dextromethorphan Hydrobromide 6.6 mg/5 mL	Vick’s Formula 44 Custom Care Chesty Cough	Procter & Gamble
		100 mg/5mL with Acetaminophen 162.5 mg/5 mL, Dextromethorphan Hydrobromide 5 mg/5 mL, and Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Mucinex Cold, Cough, and Sore Throat	Reckitt Benckiser
			Children’s Mucinex Multi-symptom Cold & Fever	Reckitt Benckiser
		100 mg/5 mL with Dextromethorphan Hydrobromide 5 mg/5 mL	Children’s Mucinex Cough	Reckitt Benckiser
			Pediacare Children’s Cough & Congestion	Prestige Brands
		100 mg/5 mL with Dextromethorphan Hydrobromide 5 mg/5 mL and Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Mucinex Multi-symptom Cold	Reckitt Benckiser
		100 mg/5 mL with Dextromethorphan Hydrobromide 10 mg/5 mL	Robitussin Peak Cold Cough + Chest Congestion DM	Pfizer
		100 mg/5 mL with Dextromethorphan Hydrobromide 10 mg/5 mL and Phenylephrine Hydrochloride 5 mg/5 mL	Robitussin Peak Cold Multi-Symptom Cold	Pfizer
		100 mg/5 mL with Phenylephrine Hydrochloride 2.5 mg/5 mL	Children’s Mucinex Stuffy Nose & Cold	Reckitt Benckiser
		100 mg/5 mL with Phenylephrine Hydrochloride 5 mg/5 mL	Rescon-GG	Capellon
		200 mg/5 mL with Dextromethorphan Hydrobromide 10 mg/5 mL	Robitussin Peak Cold Maximum Strength Cough + Chest Congestion DM	Pfizer
		200 mg/5 mL with Dextromethorphan Hydrobromide 10 mg/5 mL and Phenylephrine Hydrochloride 5 mg/5 mL	Robitussin Peak Cold Maximum Strength Multi-Symptom Cold	Pfizer
	Tablets	200 mg with Acetaminophen 325 mg, Dextromethorphan 10 mg, and Phenylephrine Hydrochloride 5 mg	Tylenol Cold Multi-symptom Severe	McNeil
			Tylenol Cold & Flu Severe	McNeil
		200 mg with Ephedrine Hydrochloride 12.5 mg	Primatene	Pfizer
		400 mg with Ephedrine Sulfate 25 mg	Bronkaid Dual Action Caplets	Bayer
		400 mg with Pseudoephedrine Hydrochloride 60 mg	Congestac Caplets	Ascher
	Tablets, extended-release	600 mg with Dextromethorphan Hydrobromide 30 mg	Mucinex DM	Reckitt Benckiser
		600 mg with Pseudoephedrine Hydrochloride 60 mg	Mucinex D	Reckitt Benckiser
		1.2 g with Dextromethorphan Hydrobromide 60 mg	Mucinex DM Maximum Strength	Reckitt Benckiser
		1.2 g with Pseudoephedrine Hydrochloride 120 mg	Mucinex D Maximum Strength	Reckitt Benckiser