GUAIFENESIN

(gwye-fen'e-sin)

Anti-Tuss, GG-Cen, Glyceryl Guaiacolate, Glycotuss, Glytuss, Guiatuss, Humibid, Hytuss, Malotuss, Mytussin, Mucinex, Resyl

, Robitussin
Classifications: expectorant;
Therapeutic: expectorant
Pregnancy Category: C

Availability

100 mg/5 mL syrup; 100 mg/5 mL, 200 mg/5 mL liquid; 200 mg capsules; 300 mg sustained release capsules; 100 mg, 200 mg, 1200 mg tablets; 600 mg sustained release tablets

Action

Enhances reflex outflow of respiratory tract fluids by irritation of gastric mucosa.

Therapeutic Effect

Aids in expectoration by reducing adhesiveness and surface tension of secretions.

Uses

To combat dry, nonproductive cough associated with colds and bronchitis. A common ingredient in cough mixtures.

Contraindications

Hypersensitivity to guaifenesin; pregnancy (category C), lactation. Cough due to CHF, ACE inhibitor therapy, or tobacco smoking.

Cautious Use

Chronic cough; asthma; lactation.

Route & Dosage

Cough
Adult: PO 200–400 mg q4h up to 2.4 g/d
Child: PO <2 y, 12 mg/kg/d in 6 divided doses; 2–5 y, 50–100 mg q4h up to 600 mg/d; 6–11 y, 100–200 mg q4h up to 1.2 g/d

Administration

Oral

Ensure that sustained release form of drug is not chewed or crushed. It must be swallowed whole.
Follow dose with a full glass of water if not contraindicated.
Carefully observe maximum daily doses for adults and children.

Adverse Effects (≥1%)

GI: Low incidence of nausea. CNS: Drowsiness.

Diagnostic Test Interference

Guaifenesin may produce color interference with certain laboratory determinations of urinary 5-hydroxyindoleacetic acid (5-HIAA) and vanillylmandelic acid (VMA).

Interactions

Drug: By inhibiting platelet function, guaifenesin may increase risk of hemorrhage in patients receiving heparin therapy.

Nursing Implications

Assessment & Drug Effects

Monitor for therapeutic effectiveness. Persistent cough may indicate a serious condition requiring further diagnostic work.
Notify physician if high fever, rash, or headaches develop.

Patient & Family Education

Increase fluid intake to help loosen mucus; drink at least 8 glasses of fluid daily.
Contact physician if cough persists beyond 1 wk.
Contact physician if high fever, rash, or headache develops.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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