9
Table 2b. Commonly Used Medications
Medication
(Brand)
Recommended
Dose Range
(mg/day)
a
Half-life
(hours) Drug Interactions
a
Atypical antipsychotic agents
Aripiprazole
(Abilify
®
)
10-30 75 Half dose with strong CYP3A4 or
CYP2D6 inhibitors.
Double dose with CYP3A4 inducers
Asenapine
(Saphris
®
)
10-20 13-39 Cautiously approach coadministration
with fluvoxamine and paroxetine
Sublingual administration without food or
drink for 10 minutes aer administration
Clozapine
(Clozaril
®
)
150-450 (FDA
max 900 mg )
12 Cautiously approach coadministration
with drugs that involve CYP1A2,
CYP2D6 and CYP3A4
Iloperidone
(Fanapt
®
)
12-24 18-33 Half dose with strong CYP2D6 and
CYP3A4 inhibitors
Half dose in poor metabolizers of
CYP2D6
Lurasidone
(Latuda
®
)
40-160 18-31 Not recommended with strong CYP3A4
inhibitors or inducers
Reduce dose with moderate CYP3A4
inhibitors
Give aer ≥350 calorie snack or meal
Olanzapine
(Zyprexa
®
)
10-30 (some
studies allow
40 mg or more
for difficult cases)
33 Dose adjustment may be required with
carbamazepine, fluvoxamine, fluoxetine,
omeprazole and rifampin
Paliperidone
ER (Invega
®
)
3-12 23 Dose adjustment may be required with
carbamazepine and divalproex sodium
Quetiapine
(Seroquel
®
,
Quetiapine
XR
®
)
300-750 (some
settings allow
1200 mg
or more for
difficult cases)
6-7 A decrease in dose may be required with
CYP3A and CYP2D6 inhibitors
An increase in dose may be required
with hepatic enzyme inducers such as
carbamazepine, phenytoin, barbiturates,
rifampicin, sulphonylureas, griseofulvin
and excess alcohol
Risperidone
(Risperdal
®
)
2-8 24 Dose adjustment may be required
with cimetidine, ranitidine, clozapine,
fluoxetine, paroxetine, carbamazepine and
other known enzyme inducers
Ziprasidone
(Geodon
®
)
80-160 (some
settings allow up
to 320 mg for
difficult cases)
7 Dose adjustment may be required with
CYP3A4 inhibitors and inducers
a
Dose range recommendations are adapted from the 2009 Schizophrenia Patient Outcome
Research Team recommendations. See full prescribing information for details.
