Annotation

Codeine is indicated for treatment of mild to moderate pain as well as for controlling coughing. Excerpts from the codeine product monograph:

Ultra-Rapid Metabolizers of Codeine. Some individuals may be ultra-rapid metabolizers due to a specific CYP2D6*2x2 genotype. These individuals convert codeine into its active metabolite, morphine, more rapidly and completely than other people. This rapid conversion results in higher than expected serum morphine levels. Even at labeled dosage regimens, individuals who are ultra-rapid metabolizers may experience overdose symptoms such as extreme sleepiness, confusion, or shallow breathing.

Lactation. Codeine is secreted into human milk...some women are ultra-rapid metabolizers of codeine. These women achieve higher-than-expected serum levels of codeine's active metabolite, morphine, leading to higher-than-expected levels of morphine in breast milk and potentially dangerously high serum morphine levels in their breastfed infants...maternal use of codeine can potentially lead to serious adverse reactions, including death, in nursing infants.

For the complete product monograph text with sections containing pharmacogenetic information highlighted, see the codeine product monograph.

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