MUCINEX 600/MG ER TAB 20/TAB

Indications

Approved Uses

Relief of chest congestion by loosening phlegm (mucus) and thinning bronchial secretions to make coughs more productive.

Dosage & Administration

Dosing by Condition

Adults and children ≥12 years (extended-release): 600 mg every 12 hours; may increase to 1200 mg every 12 hours if needed; maximum 2400 mg/day.

Initial Dose

600mg every 12 hours (extended-release tablet)

Maintenance Dose

600mg to 1200mg orally every 12 hours.

Maximum Dose

2400mg (2.4g) per 24 hours.

How to Take

Swallow the extended-release tablet whole with a full glass of water; do not crush, chew, or split. Maintain adequate fluid intake to help loosen mucus.

Side Effects

Common Side Effects

Nausea, vomiting, dizziness, headache, and gastrointestinal upset (e.g., stomach pain).

Safety & Warnings

Contraindications

Hypersensitivity to guaifenesin or any component of the formulation.

Warnings & Precautions

Do not use for persistent/chronic cough (e.g., smoking, asthma, chronic bronchitis, emphysema/COPD) or cough with excessive phlegm unless directed by a doctor; consult a doctor if cough lasts >7 days, recurs, or is accompanied by fever, rash, or persistent headache; swallow ER tablets whole (do not crush/chew/break); maintain adequate fluid intake; may interfere with urine lab tests (e.g., 5-HIAA, VMA).

Age Restriction

Not recommended for children under 12 years of age for the 600 mg extended-release tablet.

Driving Warning

No effect on ability to drive or operate machinery

Drug Interactions

Drug Interactions

No clinically significant drug-drug interactions are expected; may interfere with certain urine laboratory tests (e.g., 5-HIAA, VMA) causing false results.

Interaction Severity

No major clinically significant drug-drug interactions are expected; may interfere with certain urine laboratory tests (e.g., 5-HIAA/VMA) causing false results.

Food Interaction

No clinically significant food interaction; may be taken with or without food. Encourage adequate water intake.

Special Populations

Pregnancy

Consult Doctor

Breastfeeding

Consult Doctor

Elderly

Standard adult dosing; ensure adequate hydration

Liver Impairment

No specific dose adjustment recommended; use with caution in significant hepatic impairment due to limited data.

Storage & Patient Advice

Missed Dose

Take as soon as remembered; skip if it is almost time for the next dose. Do not double the dose.

Stopping the Medicine

Safe to stop anytime; no tapering required (typically stop when symptoms resolve).

Patient Counseling

Swallow extended-release tablet whole; do not crush, chew, or split. Take with a full glass of water and maintain adequate hydration to help loosen/thin mucus. Do not exceed labeled maximum: 1200 mg every 12 hours (max 2400 mg/day) unless directed by a clinician. Seek medical advice if cough lasts >7 days, recurs, or is accompanied by fever, rash, or headache.

Monitoring Requirements

No routine monitoring required

Pharmacology

Mechanism of Action

Increases the volume and decreases the viscosity of respiratory tract secretions, facilitating mucociliary clearance and expectoration.

Onset of Action

Approximately 30-60 minutes.

Duration of Effect

Approximately 12 hours (extended-release tablet).

Half-Life

Approximately 1 hour.

Bioavailability

Well absorbed from the gastrointestinal tract after oral administration (absolute bioavailability not well characterized in publicly available labeling).

Metabolism

Hepatic metabolism to inactive metabolites, including beta-(2-methoxyphenoxy) lactic acid.

Excretion

Renal; excreted primarily in urine mainly as inactive metabolites (with a small amount as unchanged drug).

Product Information

Available Dosage Forms

For this PRODUCT: extended-release oral tablet (bi-layer). In general, guaifenesin is also marketed in immediate-release tablets/capsules and oral liquids/solutions/syrups and granules (varies by country/brand).

Composition per Dose

Each extended-release bi-layer tablet: 600mg guaifenesin (immediate-release layer + extended-release layer)

Generic Availability

Yes

OTC Alternatives

OTC guaifenesin immediate-release tablets/capsules (e.g., 200 mg or 400 mg) and OTC guaifenesin oral liquids/syrups (various concentrations), depending on local market.

Symptom Target

Congestion, Cough

Sedating

No

Reviewed by Al Mujtama Pharmacy Medical Review Team. Last reviewed 07-07-2026