Class: Antitussive, Opioid/Expectorant Combination Product, C-V
Dosage Forms. Syrup: (codeine/guaifenesin) 10 mg/5 mL-100 mg/5 mL
Common FDA Label Indication and Dosing.
1. Cough, due to minor throat and bronchial irritation: Adults and Children 12 y and older: 5-10 mL (codeine 10-20 mg/guaifenesin 100-200 mg) po q4-6h prn; not to exceed 60 mL/24 h; Children 6-12 y old: 2.5-5 mL (codeine 10-20 mg/guaifenesin 100-200 mg) po q4-6h prn; not to exceed 30 mL/24 h
Off-Label Uses. None
MOA. Codeine is 3-methoxymorphine, a phenanthrene opioid with very low affinity for opioid receptors. It works as an antitussive through suppression of the cough reflex by directly affecting the cough center in the medulla. Guaifenesin works by thinning bronchial secretions and increasing sputum volume, thereby promoting lower respiratory tract drainage and removal of mucus.
Drug Characteristics: Guaifenesin/Codeine
Medication Safety Issues: Guaifenesin/Codeine
Drug Interactions: Guaifenesin/Codeine
Adverse Reactions: Guaifenesin/Codeine
Efficacy Monitoring Parameters. Relief of cough.
Toxicity Monitoring Parameters. Seek medical attention if severe skin rash, excessive drowsiness, and decreased respiration.
Key Patient Counseling Points. If using chronically, use a stool softener and/or laxative for preventing constipation. May cause drowsiness; avoid driving or other tasks requiring motor coordination. Avoid alcohol.
Clinical Pearls. Three deaths occurred in children receiving codeine for pain relief after tonsillectomy; all 3 were CYP2D6 ultrarapid metabolizers. Use caution in elderly, appear more sensitive to the effects. Use concurrent CNS depressants with caution, may have additive effects. Tolerance and physical dependence may occur with chronic use, avoid abrupt discontinuation. CYP2D6 inhibitors may also prevent activation of codeine to morphine. Products with various concentrations of guaifenesin/codeine solutions are available.