The CYP2D6*5 allele is assigned as a no function allele by CPIC. Patients carrying the CYP2D6*5 allele in combination with a no, decreased or normal function allele may have decreased metabolism of fluvoxamine as compared to patients with alleles that result in a normal metabolizer phenotype. However, conflicting evidence has been reported. This annotation only covers the pharmacokinetic relationship between CYP2D6 and fluvoxamine and does not include evidence about clinical outcomes. Be aware that the CPIC guideline for fluvoxamine and CYP2D6 has a 鈥榥o recommendation鈥?for ultrarapid metabolizers. 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 fluvoxamine.