DrugindexOnline^{2nd edition}

Pronouncation: (GWHY-fen-ah-sin/KOE-deen FOSS-fate)
Class: Antitussive with expectorants

Trade Names:
Guaitussin AC
- Syrup 10 mg codeine phosphate and 100 mg guaifenesin per 5 mL

Trade Names:
Mytussin AC
- Syrup 10 mg codeine phosphate and 100 mg guaifenesin per 5 mL

Trade Names:
Romilar AC
- Syrup 10 mg codeine phosphate and 100 mg guaifenesin per 5 mL

Mechanism of Action

Pharmacology

Guaifenesin

May enhance output of respiratory tract fluid by reducing adhesiveness and surface tension, enhancing removal of viscous mucus, and making nonproductive coughs more productive and less frequent.

Codeine

Stimulates opiate receptors in CNS; also causes suppression of cough.

Indications and Usage

Temporary control of cough caused by minor throat and bronchial irritation as occurs with common cold or inhaled irritants; assists in loosening phlegm (mucus) and thins bronchial secretions to make cough more productive.

Contraindications

Hypersensitivity to any component of product.

Dosage and Administration

Administer with special measuring device for accurate dose.

Adults and Children 12 yr of age and older

PO 1 tsp (5 mL) to 2 tsp (10 mL) every 4 to 6 h (max, 12 tsp [60 mL] in 24 h).

Children 6 to younger than 12 yr of age

PO ½ tsp (2.5 mL) to 1 tsp (5 mL) every 4 to 6 h (max, 6 tsp [30 mL] in 24 h).

Children younger than 6 yr of age

PO As directed by health care provider.

General Advice

• Give with food or milk if GI upset occurs.
• Use dosing spoon or syringe for pediatric doses.

Storage/Stability

Store syrup at controlled room temperature (59° to 86°F). Keep tightly capped.

Drug Interactions

Antidepressants (eg, MAOIs), sedatives (eg, barbiturates), tranquilizers (eg, benzodiazepines)

May cause increased drowsiness.

Laboratory Test Interactions

Guaifenesin may interfere with the interpretation of the test for urinary 5-hydroxyindoleacetic acid for the diagnosis of carcinoid syndrome.

Adverse Reactions

Cardiovascular

Codeine

Hypotension; orthostatic hypotension; bradycardia; tachycardia; shock.

CNS

Guaifenesin

Dizziness; headache.

Codeine

Lightheadedness; dizziness; sedation; disorientation; incoordination; euphoria; delirium.

Dermatologic

Guaifenesin

Rash; urticaria.

Codeine

Sweating; pruritus; urticaria.

EENT

Codeine

Miosis.

GI

Guaifenesin

Nausea; vomiting.

Codeine

Nausea; vomiting; constipation; abdominal pain; anorexia; biliary tract spasm.

Genitourinary

Codeine

Urinary retention or hesitancy.

Respiratory

Codeine

Laryngospasm; depression of cough reflex; respiratory depression.

Miscellaneous

Codeine

Tolerance; psychological and physical dependence with chronic use.

Precautions

Children

Not recommended for children younger than 2 yr of age.

Dependence

Codeine has abuse potential; may be habit forming.

Persistent cough

Persistent cough may be a sign of a serious condition. Consult health care provider for a cough of more than 1 wk duration or for a cough accompanied by fever, rash, or persistent headache. Do not use for chronic or persistent cough, cough accompanied by excessive phlegm (mucus), shortness of breath, or chronic pulmonary disease without consulting health care provider.

Overdosage

Symptoms

Miosis, respiratory and CNS depression, circulatory collapse, seizures, cardiopulmonary arrest, death.

Patient Information

• Advise patient to take prescribed dose every 4 h as needed, up to 6 times/day.
• Advise caregiver to use dosing spoon or syringe when giving liquid to children.
• Advise patient to take with food or milk if GI upset occurs.
• Advise patient that if a dose is missed to take as soon as remembered unless it is nearing time for the next dose. Caution patient to not double the dose to catch up.
• Advise patient that if cough is not controlled, not to increase the dose of medication but to inform health care provider.
• Caution patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.
• Advise patient to avoid alcohol and other CNS depressants because of risk of excessive sedation.