A case report of a poor metabolizer of CYP2D6 presented with unusual responses to nortriptyline medication.
We present a case with decreased metabolic activity of CYP2D6, a cytochrome P450 enzyme catalyzing the metabolism of nortriptyline (NT). Conventional dosage regimen led to toxic plasma concentration of NT and adverse effects such as dry mouth, constipation, and dizziness in this case with genotype CYP2D6*5/*10B. This case suggests the clinical usefulness of pharmacogenetic testing in individualized dosage adjustments of NT.
Lee
Soo-Youn
SY
Department of Laboratory Medicine, Sungkyunkwan University School of Medicine Samsung Medical Center, Seoul, Korea.
Ki
Chang-Seok
CS
Hong
Kyung Sue
KS
Kim
Jong Won
JW
D000929:Antidepressive Agents, Tricyclic / Q000009:adverse effects* / Q000493:pharmacokinetics; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics* / Q000378:metabolism; D003863:Depression / Q000188:drug therapy* / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009661:Nortriptyline / Q000009:adverse effects* / Q000493:pharmacokinetics
D000929:Antidepressive Agents, Tricyclic; D009661:Nortriptyline; D019389:Cytochrome P-450 CYP2D6