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Codeine / Guaifenesin Dosage

Medically reviewed by Last updated on Jan 5, 2022.

Applies to the following strengths: 10 mg-100 mg/5 mL; 10 mg-300 mg; 2.5 mg-75 mg/5 mL; 10 mg-300 mg/5 mL; 10 mg-200 mg/5 mL; 7.5 mg-225 mg/5 mL; 9 mg-200 mg; 6.3 mg-100 mg/5 mL; 10 mg-400 mg; 20 mg-400 mg; 8 mg-200 mg/5 mL

Usual Adult Dose for:

Additional dosage information:

Usual Adult Dose for Cough

1 dose orally every 4 to 6 hours as needed
-Codeine: Single dose: up to 20 mg; Maximum dose: 120 mg in 24 hours
-Guaifenesin: Single dose: up to 400 mg; Maximum dose: 2400 mg in 24 hours
Maximum dose should not exceed maximum dose of either of the single ingredient doses

-Liquid preparations should be measured with an accurate milliliter measuring device.
-This combination drug should not be used in patients with chronic pulmonary disease or shortness of breath unless directed by a health care professional.

Uses: Temporary relief of coughs due to minor throat and bronchial irritations as may occur with the common cold or inhaled irritants; helps loosen phlegm and thin bronchial secretions to make cough more productive.

Renal Dose Adjustments

Dose adjustments not recommended

Liver Dose Adjustments

Dose adjustments not recommended


The US FDA requires a Risk Evaluation and Mitigation Strategy (REMS) for all opioids intended for outpatient use. The new FDA Opioid Analgesic REMS is a designed to assist in communicating the serious risks of opioid pain medications to patients and health care professionals. It includes a medication guide and elements to assure safe use. For additional information:

-Opioid Analgesic REMS: To ensure that the benefits of opioid analgesics outweigh the risks of addiction, abuse, and misuse, a REMS is required for these products. Under the requirements of the REMS, drug companies with approved opioid analgesic products must make REMS-compliant education programs available to healthcare providers. Healthcare providers are strongly encouraged to complete a REMS-compliant education program; counsel patients and/or their caregivers, with every prescription on safe use, serious risks, storage, and disposal of these products; emphasize to patients and their caregivers the importance of reading the Medication Guide every time it is provided by their pharmacist, and consider other tools to improve patient, household, and community safety.

The US FDA recommends against use of codeine-containing cough and cold medications in patients less than 18 years because it has been determined that the risks outweigh benefits.

Consult WARNINGS section for additional precautions.

US Controlled Substance: Schedule V


Data not available

Other Comments

Administration advice:
-Take orally with or without food; take with plenty of water
-Oral measuring devices should be provided to ensure accuracy in dosing; a household teaspoon should not be considered an accurate measuring device

Storage requirements:
-Protect from moisture and light

-Patients who are ultra-rapid metabolizers of codeine due to a CYP450 2D6 polymorphism, will convert codeine more rapidly and completely to morphine resulting in unexpectedly high morphine levels, which may be life-threatening.
-Codeine use is contraindicated in the postoperative period in children who have undergone tonsillectomy and/or adenoidectomy.

-Cardiovascular: Monitor for signs of hypotension, especially in those whose blood pressure is compromised
-Respiratory: Monitor for respiratory depression
-Gastrointestinal: Monitor for constipation and decreased bowel motility in post-operative patients.
-Patients should be monitored for the development of addiction, abuse, or misuse.

Patient advice:
-Patients should understand that codeine use can result in addiction, abuse, and misuse.
-Patients should understand that this product is for temporary relief of cough; if cough persists for longer than 1 week, recurs, or is accompanied by fever, rash, or persistent headaches, a health care professional should be consulted.
-Patients should understand risks of life-threatening respiratory depression and when this risk is greatest; patients should be aware that a genetic mutation may result in greater codeine toxicity in some patients; breastfed infants of women who have this genetic mutation are also at risk.
-Women who are breastfeeding, pregnant, or planning to become pregnant should speak to their healthcare provider before using this product.
-This drug may cause drowsiness, dizziness, or impair thinking or motor skills; patients should avoid driving or operating machinery while taking this drug.
-Concomitant use of alcohol, sedatives, and tranquilizers may increase drowsiness; patients should avoid alcohol and consult with their healthcare provider regarding concomitant use of other CNS depressants
-Patients should be instructed to read the US FDA-approved Medication Guide each time this drug is dispensed; they should understand the safe use, serious risks, and proper storage and disposal of this drug.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.