Patients carrying the CYP2D6*1 allele in combination with another normal function allele may have an increased clearance of mirtazapine as compared to patients with two no function alleles and a decreased clearance of mirtazapine as compared to patients with an increased function allele in combination with a normal function allele. However, conflicting evidence has been reported. This drug-variant pair has been assigned a 鈥渘o recommendation鈥?by DPWG, as it was determined to be not clinically actionable. Other genetic and clinical factors may also influence metabolism of mirtazapine. This annotation only covers the pharmacokinetic relationship between CYP2D6 and mirtazapine and does not include evidence about clinical outcomes.