Background: The Canadian Network for Mood and Anxiety Treatments (CANMAT) conducted a revision of the 2009 guidelines by updating the evidence and recommendations. The scope of the 2016 guidelines remains the management of major depressive disorder (MDD) in adults, with a target audience of psychiatrists and other mental health professionals. Methods: Using the question-answer format, we conducted a systematic literature search focusing on systematic reviews and meta-analyses. Evidence was graded using CANMAT-defined criteria for level of evidence. Recommendations for lines of treatment were based on the quality of evidence and clinical expert consensus. ''Pharmacological Treatments'' is the third of six sections of the 2016 guidelines. With little new information on older medications, treatment recommendations focus on second-generation antidepressants.Results: Evidence-informed responses are given for 21 questions under 4 broad categories: 1) principles of pharmacological management, including individualized assessment of patient and medication factors for antidepressant selection, regular and

nature publishing groupPolymorphisms in CYP2D6 and CYP2C19 affect the efficacy and safety of tricyclics, with some drugs being affected by CYP2D6 only, and others by both polymorphic enzymes. Amitriptyline, clomipramine, doxepin, imipramine, and trimipramine are demethylated by CYP2C19 to pharmacologically active metabolites. These drugs and their metabolites, along with desipramine and nortriptyline, undergo hydroxylation by CYP2D6 to less active metabolites. Evidence from published literature is presented for CYP2D6 and CYP2C19 genotype-directed dosing of tricyclic antidepressants.The use of tricyclics to treat psychological disorders has declined in part because of the occurrence of undesirable side effects. Although tricyclics are still used to treat depression, 1 their main therapeutic use is often for pain management. 2,3 Interindividual differences in side effects and treatment response have been associated with variability of tricyclic plasma concentrations. 4,5 Because both enzymes influence plasma concentrations, the effectiveness and tolerability of tricyclics are affected by CYP2D6 metabolism and partially by CYP2C19 metabolism. 4 The purpose of this guideline is to provide information regarding how to use existing CYP2D6 and/or CYP2C19 genotyping test results to guide dosing of tricyclics for psychological disorders and pain management, focusing particularly on amitriptyline and nortriptyline.Optimal therapeutic plasma concentrations for the tricyclics have been defined. 6 Poor or ultrarapid metabolizers of CYP2D6 and CYP2C19 may have tricyclic plasma concentrations outside the recommended therapeutic range, thereby increasing the risk of treatment failure or side effects. 7-10 Therefore, this guideline takes into consideration both clinical outcomes and observed tricyclic plasma concentrations based on genotype/phenotype characteristics. Detailed guidelines for use of other laboratory tests including therapeutic drug monitoring of tricyclics are beyond the scope of this article. The Clinical Pharmacogenetics Implementation Consortium (CPIC) of the National Institutes of Health's Pharmacogenomics Research Network develops peer-reviewed gene-drug guidelines that are published and updated periodically at http://www.pharmgkb.org based on new developments in the field. FOCUSED LITERATURE REVIEWA systematic literature review focused on CYP2D6 and CYP2C19 genotyping and its relevance to gene-based dosing of tricyclics was conducted (see Supplementary Data online). This guideline was developed based on interpretation of the literature by the authors and experts in the field. GENES: CYP2D6 AND CYP2C19 CYP2D6 backgroundThe CYP2D6 gene is highly polymorphic. 11 More than 100 known allelic variants and subvariants have been identified, and there are substantial ethnic differences in observed allele frequencies (Supplementary Data online). The most commonly reported CYP2C19 backgroundSimilar to CYP2D6, the CYP2C19 gene is highly polymorphic; more than 30 known allelic variants and subvariants have been identif...

The Clinical Pharmacogenetics Implementation Consortium (CPIC) publishes genotype-based drug guidelines to help clinicians understand how available genetic test results could be used to optimize drug therapy. CPIC has focused initially on well-known examples of pharmacogenomic associations that have been implemented in selected clinical settings, publishing nine to date. Each CPIC guideline adheres to a standardized format and includes a standard system for grading levels of evidence linking genotypes to phenotypes and assigning a level of strength to each prescribing recommendation. CPIC guidelines contain the necessary information to help clinicians translate patient-specific diplotypes for each gene into clinical phenotypes or drug dosing groups. This paper reviews the development process of the CPIC guidelines and compares this process to the Institute of Medicine’s Standards for Developing Trustworthy Clinical Practice Guidelines.

Opioids are mainly used to treat both acute and chronic pain. Several opioids are metabolized to some extent by CYP2D6 (codeine, tramadol, hydrocodone, oxycodone, and methadone). Polymorphisms in CYP2D6 have been studied for an association with the clinical effect and safety of these drugs. Other genes that have been studied for their association with opioid clinical effect or adverse events include OPRM1 (mu receptor) and COMT (catechol‐O‐methyltransferase). This guideline updates and expands the 2014 Clinical Pharmacogenetics Implementation Consortium (CPIC) guideline for CYP2D6 genotype and codeine therapy and includes a summation of the evidence describing the impact of CYP2D6, OPRM1, and COMT on opioid analgesia and adverse events. We provide therapeutic recommendations for the use of CYP2D6 genotype results for prescribing codeine and tramadol and describe the limited and/or weak data for CYP2D6 and hydrocodone, oxycodone, and methadone, and for OPRM1 and COMT for clinical use.