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guaifenesin (gwye-fen-e-sin)

Alfen Jr, Altarussin, Benylin-E, Breonesin, Calmylin Expectorant, Diabetic Tussin, Ganidin NR, Guiatuss, Hytuss, Hytuss-2X, Mucinex, Naldecon Senior EX, Organidin NR, Resyl, Robitussin, Scot-tussin Expectorant, Siltussin SA, Siltussin DAS


Therapeutic: allergy, cold, and cough remedies, expectorant


Coughs associated with viral upper respiratory tract infections.


Reduces viscosity of tenacious secretions by increasing respiratory tract fluid. Therapeutic Effects: Mobilization and subsequent expectoration of mucus.

Adverse Reactions/Side Effects

CNS: dizziness, headache. GI: nausea, diarrhea, stomach pain, vomiting. Derm: rashes, urticaria.


Examination and Evaluation

  • Assess the quantity and consistency of sputum to help document whether this drug is successful in reducing the viscosity of respiratory secretions.

  • Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.


  • When implementing airway clearance techniques or other pulmonary interventions, attempt to intervene when the drug has produced expectorant effects. Effects typically begin 30 min after oral administration.

  • Design and implement breathing exercises to maximize ventilation and help prevent infections caused by pulmonary congestion.

Patient/Client-Related Instruction

  • Instruct patient and family/caregivers to report other troublesome side effects such as severe or prolonged headache, skin reactions (rash, welts), or GI problems (diarrhea, nausea, vomiting, stomach pain).


Absorption: Well absorbed after oral administration.

Distribution: Unknown.

Metabolism and Excretion: Renally excreted as metabolites.

Half-life: Unknown.

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TIME/ACTION PROFILE (expectorant action)

PO 30 min unknown 4–6 hr
PO-ER unknown unknown 12 hr


Contraindicated in: Hypersensitivity; Some products contain alcohol and should be avoided in patients with known intolerance; Some products contain aspartame and should be avoided in patients with phenylketonuria.

Use Cautiously in: Cough lasting >1 wk or accompanied by fever, rash, or headache; Pregnancy (although safety has not been established, guaifenesin has been used without adverse effects); Patients receiving disulfiram (liquid products may contain alcohol); Diabetic patients (some products may contain sugar); Children (check age limitations on specific dose forms).


Drug-Drug: None significant.


PO (Adults): 200–400 mg q 4 hr or 600–1200 mg q 12 hr as extended-release product (not to exceed 2400 mg/day).

PO (Children 6–12 yr): 100–200 mg q 4 hr or 600 mg q 12 ...

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