• More than 100 alleles
• Multiple copies- the more copies, the
more active the enzyme
• Ultrarapid (UM)
• Extensive (EM)
• Intermediate (IM)
• Poor (PM)
• CYP2D6 PMs are likely to have poor
tolerance of TCAs and Venlafaxine
• CYP2D6 UMs are likely to have low
levels of TCAs and Venlafaxine
• Try BCEMS (Bupropion, Citalopram,
Escitalopram, Mirtazapine, Sertraline)
• A fellow-psychiatrist calls you, describing one
of her complex patients with bipolar disorder.
The patient’s history is long and complicated.
In brief, he did not respond to mood
stabilizers, Wellbutrin, Seroquel, Geodon, etc.
This led the treating psychiatrist to believe
that the patient must be a UM, and she
wanted to know how he could be tested.
• A 23-year-old patient with borderline personality traits
was admitted to the hospital. The patient has had a
pattern of utilizing multiple emergency rooms, with
false allegations of symptoms. Problems have included
use of drugs or alcohol, psychotic symptoms, and
suicidal and homicidal ideation. During this admission,
he complained of "voices," was treated with
perphenazine, 4 mg/day, and developed a severe case
of stiffness. Several years ago he received a high dose of
parenteral haloperidol and developed a serious case of
neuroleptic malignant syndrome. There are also some
indications that the patient may have developed
priapism on trazadone.
Before testing your patient
• Remember- clinical applications are still
• Most labs will only tell you if patient
has >3 copies.
• Current testing may have false