Hospital Pharmacy - December 2019 - 390

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Hospital Pharmacy 54(6)

Table 1.6,7 Average Wholesaler Price Per Tablet.

Results

Paliperidone Extended-Release

In the 6-month study period, approximately 68% (62) of all
paliperidone ER utilization was for its approved indication
of schizophrenia and schizoaffective disorder. The other
32% (38) of utilization was either off-label or for approved
indications of risperidone (Table 2).
The total sum of paliperidone ER therapy cost for 100
patients in the span of 6 months was $17 338.36. If all the
paliperidone ER therapy were to be converted to risperidone,
the cost of therapy for the same 100 patients over the 6-month
therapy would be $436.43. The potential cost savings when
converting patients from paliperidone ER to risperidone
would be $16 901.93 per 100 patients. Per year, this would
yield projected savings of approximately $33 800 per year
per 100 patients prescribed paliperidone, assuming the prescribed doses remain consistent with current mean doses.
The projected savings is based on the same 100 study patients
having consistent paliperidone ER usage for a year. Average
cost savings of per patient with conversion is estimated at
$169 per patient.
Average cost per milligram of paliperidone per patient
across all indications was $2.77, while risperidone cost was
$0.09, yielding a cost difference of $2.68 per milligram of
drug per patient for all recorded indications. Average cost of
risperidone per milligram per patient was about the same for
all indications at $0.09, while for paliperidone, cost varied
minimally depending on the indication. The lowest average
cost was seen in patients with schizophrenia ($2.73), while
indications in the "other" category (not schizophrenia, major
depressive disorder, nor bipolar disorder) had the highest
average cost (Table 3).
Based on the mean dosing of paliperidone used, potential
cost savings per patient was calculated versus risperidone.
Total costs of paliperidone therapy were calculated using
mean doses in each indication and compared with total risperidone cost per patient. The indication of major depressive
disorder had the highest potential cost savings of $379.48,
due to the high mean total of paliperidone taken (139 mg).
The lowest cost was under the indication of "other" at
$156.38, with the lowest mean total dose taken of paliperidone (55 mg). Potential cost savings for indications of
schizophrenia and bipolar disorder came in between $189.57
and $177.28, respectively (Table 4).

Strength
3 mg
6 mg
9 mg

Risperidone

Price

Strength

Price

$16.05
$13.90
$18.87

2 mg
4 mg
6 mg

$0.23
$0.36
$0.46

and therapeutics committee in inpatient hospitals is to maintain the hospital formulary through selection of the most costeffective agents with minimal therapeutic redundancy. Many
inpatient hospitals carry multiple antipsychotics on the formulary to accommodate patients with different response profiles;
however, in this instance, a response to risperidone or paliperidone should predict a response to the either agent. Therefore,
there is limited necessity in maintaining both agents on formulary with the expected similar therapeutic response and tolerability to both agents and the cost of paliperidone.

Methods
The Institutional Review Board approved this retrospective
study.

Study Design and Patient Population
This was a retrospective drug utilization review conducted at
an inpatient psychiatric hospital. The primary objective was
to evaluate prescribing patterns of paliperidone ER tablets
and to assess potential cost savings if risperidone replaced
paliperidone ER on the formulary.
The study population included 100 patients, 18 years and
older, receiving oral paliperidone ER over a 6-month period.
Patients who were prescribed paliperidone ER, but never
received or refused doses were excluded. The data were
obtained via the electronic medical record. The data collected included patient demographics (age, sex, and race),
indication of paliperidone therapy, dose of the medication,
and the length of stay. The cost of each patient's oral paliperidone ER pharmacotherapy was calculated using pricing
obtained from the hospitals wholesaler details expected AWP
per tablet (Table 1). Total paliperidone ER cost was calculated by using the AWP of the corresponding milligram tablet
multiplied by the amount of tablets used for each patient. An
equivalent total dose of risperidone therapy was calculated
using 3:2 paliperidone ER to risperidone conversion.7
Patients on 3, 6, or 9 mg paliperidone ER tablets were accurately converted to the equivalent oral risperidone doses of 2,
4, and 6 mg, respectively, and multiplied by the AWP.7 The
total amounts of paliperidone ER tablets taken during the
whole length of stay were taken into account. The cost savings were then analyzed by comparing the total costs of paliperidone ER with risperidone equivalents by the breakdown
of costs by indication.

Discussion
This retrospective analysis suggests there are potential
opportunities for cost savings if paliperidone ER was to be
substituted with risperidone. The average cost difference per
milligram per patient for the treatment of schizophrenia is
$2.64 per patient. Based on mean doses for schizophrenia,
the potential cost savings per patient is about $190. Inpatient
hospitals may consider removal of paliperidone from the formulary to reduce drug inventory and drug acquisition costs
with no anticipated effect on patients.

Hospital Pharmacy - December 2019

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