CYP2D6 genotypes in revolving door patients with bipolar disorders: A case series.

ABSTRACT

RATIONALE In psychiatric disorders, interindividual differences in cytochrome P450 (CYP)2D6 (CYP2D6) enzymatic activity could be responsible of adverse drug reactions (ADRs) and therapeutic failures (TFs) for CYP2D6-metabolized drugs, contributing to the periodical hospital readmissions of the revolving door (RD) condition. PATIENT CONCERNS We investigated CYP2D6 genotypes in a controlled series of 5 consecutive RD patients with Bipolar Disorder (BD). DIAGNOSES Psychiatric patients affected by Bipolar Disorder. INTERVENTIONS: We defined TFs as a difference at the Brief Psychiatric Rating Scale score ΔBPRS < 25% at each 1-week of stable treatment, and ADRs as the onset of extrapyramidal symptoms and/or metabolic impairment with weight gain. OUTCOMES: At 3 months, a mean number of 2.75 ±â€Š1.26 ADR and a mean ΔBPRS score of 16.07 ±â€Š0.05% were observed. At 6 months of follow-up, compared to the only patient without BD (ΔBPRS < 32.10%), BD patients (n = 4) showed TFs (ΔBPRS < 25%). CYP2D6 genotyping revealed intermediate metabolizer phenotypes for BD patients and an extensive metabolizer phenotype for the patient without BD. In BD patients, the ratio of drugs maintained/discontinued for TFs or ADRs was 1.75 for non-CYP2D6 versus 0.33 for CYP2D6 interacting drugs, while the proportion of ADRTF was 04 versus 63. LESSONS Our findings may suggest that CYP2D6 clinically relevant genotypes may be involved in the unwanted outcomes observed in RD patients with BD.