guaifenesin

Action

Exerts vasoconstrictive action that leads to decreased edema and congestion. Also increases respiratory secretions and reduces mucus viscosity.

Availability

Capsules: 200 mg

Oral solution: 100 mg/5 ml, 200 mg/5 ml

Syrup: 100 mg/5 ml

Tablets: 100 mg, 200 mg, 400 mg

Tablets (extended-release): 600 mg

Indications and dosages

➣ Cough due to upper respiratory tract infection

Adults: 200 to 400 mg P.O. q 4 hours (not to exceed 2,400 mg/day), or 600 to 1,200 mg P.O. (extended-release tablets) q 12 hours (not to exceed 2,400 mg/day)

Children ages 6 to 12: 100 to 200 mg P.O. q 4 hours (not to exceed 1,200 mg/day), or 600 mg P.O. (extended-release) q 12 hours (not to exceed 1,200 mg/day)

Children ages 2 to 6: 50 to 100 mg P.O. q 4 hours (not to exceed 600 mg/day)

Contraindications

• Hypersensitivity to drug

• Alcohol intolerance (with some products)

Precautions

Use cautiously in:

• diabetes mellitus, cough lasting more than 1 week or accompanied by fever, rash, or headache

• patients receiving disulfiram concurrently

• pregnant patients.

Administration

• Give with full glass of water.

Adverse reactions

CNS: headache, dizziness

GI: nausea, vomiting, diarrhea, stomach pain

Skin: rash, urticaria

Interactions

Drug-diagnostic tests. Urinary 5-hydroxyindoleacetic acid, vanillylmandelic acid: inaccurate results

Patient monitoring

• Assess cough quality and productivity. Reevaluate treatment if cough persists and is accompanied by fever or headache.

Patient teaching

• Tell patient to take with 8 oz of water and to drink plenty of fluids.

• Instruct patient to contact prescriber if cough lasts more than 1 week.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the tests mentioned above.