Use of anti-psychotic
medications in Long QT
General information:
a.
Anti-psychotics that prolong QT
i.
Typical anti-psychotics
1.
Low-potency are associated with higher risk of
QT prolongation
a.
Especially at higher doses – e.g. 2 g of Chlorpromazine
(a phenothiazine)
2.
High-potency anti-psychotics
a.
Fluphenazine (a phenothiazine)
b.
Pimozide (Dopamine blocker) – decreases BP.
ii.
Atypical anti-psychotics
1.
Ziprasidone
2.
Haloperidol
3.
Quetiapine
4.
Risperidone
5.
Olanzapine
6.
Thioridazine
7.
Sertindole
8.
Iloperidone
b.
Anti-psychotics that do not prolong QT
1.
Lurasidone (beware, not well tested in female)
2.
Clozapine
3.
Aripiprazole (Abilify)
3 categories:
2) 1. At risk for long QT:
a.
Risk factors:
i.
Hypokalemia, Hypocalcemia, Hypomagnesemia
ii.
Renal dysfunction, diabetes, hypothyroidism,
malnutrition and obesity – may lead to electrolyte imbalance and therefore, may
cause prolongation of QT.
b.
Options for management:
i.
Check electrolytes and for presence of risk
factors
ii.
Telemetry
iii.
Baseline EKG for QTc
iv.
Avoid psychotic polypharmacy
v.
Avoid combining with other meds that prolong QTc
vi.
Initial meds
1.
Quetiapine or Olanzapine
2.
Aripiprazole
3.
Risperidone
4.
Haloperiodol – only IM. Low or medium-dose (do
not use IV – higher risk of QT prolongation and TdP)
vii.
Atypical anti-psychotics – watch BP.
viii.
Discontinue Pimozide if used before.
ix.
If baseline QTc is normal, the following may be
used:
1.
Fluphenazine
2.
Low dose chlorpromazine
3.
Ziprasidone (avoid if there is CVD, prior AMI,
CMP, electrolyte abnormality or HT).
3)
2. Long QT < 500 ms:
a.
Aripiprazone
b.
Olanzapine
c.
Risperidone
d.
Quetiapine
i.
All 4 of the above cause decrease in BP. Therefore,
watch BP.
e.
Asenapine
f.
Lorazepam (2 mg) or Alprazolam (Zanax)
g.
Others: Ziprasidone, Valproate (check LFT),
trazodone.
4)
3. Long QT > 500 ms:
a.
If QTc > 500 ms during treatment – reconsider
that medication
b.
Rule out other risk factors – electrolyte abnormalities,
drug interactions
c.
May use Aripiprazole, Valproate, Trazodone and
Benzodiazepines
d.
Oral Loxapine (first generation, typical anti-psychotic)
inhalable form.
e.
? Perospirone (Japan)
f.
Discuss in interdisciplinary conferences
g.
Discuss in ethics committee – risk of self harm
vs. QT prolongation/TdP.
h.
Discuss non-pharmacologic treatments: Family
member stay nearby to calm patient, Music therapy.
Reference: Ries R, Sayadipour A. Management of psychosis andagitation in medical-surgical patients who have or are at risk for prolonged QTinterval. J Psychiatr Practice 2014;20:338-344.
