Clinical practice guideline: CYP2D6 genotyping for safe and efficacious codeine therapy.

This guideline is intended to provide a basis for informed decision-making regarding genetic testing to identify those individuals who will not benefit from codeine therapy, as well as those who are at an increased risk for codeine-induced toxicity. This guideline addresses the following key questions: 1) Should genetic testing for CYP2D6 be performed in patients prior to the initiation of codeine therapy? 2) How should patients with an indication for codeine therapy be managed based on their genotyping results for CYP2D6?