A Revised Argatroban Infusion Strategy Produces a Significant In-Patient Pharmacy Cost Avoidance.

Background: Argatroban (ARG) is a synthetic direct thrombin inhibitor (DTI) derived from L-arginine. ARG is approved in the U.S. for the prophylaxis or treatment of thrombosis in HIT and in pts. with or at high risk of HIT undergoing PCI. At our Institution, 254 (56%) of HIT Registry DTI-treated pts. received ARG from 1.99–12.05. In 2005, ARG accounted for 5.1% ($1,294,967) of our annual pharmacy acquisition costs and ranked #1 in single-agent costs.

Objective: To assess the impact of ARG on pt. use/24 hr, drug waste, and inpatient pharmacy average wholesale price (AWP; 2006) acquisition costs with 250 mg/250 ml D5W or NS for 24-hr. pt. titration before expiration (“Standard Formulation” group; SF) compared with 250 mg/250 ml or 100 mg/100 ml of D5W or NS with a 96-hr. infusion expiration date using light-resistant measures (“Revised Formulation” group; RF).

Design: Retrospective study utilizing a SF (1.1.06–5.31.06) vs. RF (6.1.06–7.14.06) treatment strategy; prospective drug utilization time-study (SF: 5.23.06–6.1.06).

Patients: Pts. with, a history of, or at high-risk for HIT ± thrombosis.

Setting: Tertiary-care health care system; IRB-approved HIT Registry.

Measurements: Pt. days on ARG; vial utilization/pt. day; 2006 AWP acquisition cost/vial (250 mg) for ARG ($1,139); drug utilization time-study (dose and infusion rate/pt.; drug waste); 12-month AWP acquisition cost projection analysis.

Results: In the SF group, 118 pts. received ARG for 962 pt. days with a mean of 6.4 (range, 3–13) pts. treated/day. A total of 883 vials of ARG were purchased at a mean of 177 (range, 139–224) vials/mo. with a mean of 0.92 (range, 0.75–1.03) vials utilized/pt day. In the SF group, the total acquisition cost, mean cost/mo. and per pt. day was $1,005,737, $201,147 (range, 158,321–255,136) and $1,048 (range, 854–1173), respectively. A 10-day time study was performed in 8 SF group pts. to determine ARG utilization parameters for the RF group. This showed a mean initital IV dose of 1.12 (range, 0.5 to 2.0) mcg/kg/min., a mean maintenance dose of 1.04 (range, 0.06–2.0) mcg/kg/min. The mean infusion volume was 5.1 (range, 0.32–9.2) ml/hr. The mean treatment and drug wastage volumes were 122 (range, 7.7–221) ml/24 hr/pt. and 128 (range, 29 to 242) ml/24 hr/pt. The subsequent RF group with a 96 hr. infusion expiration date included 18 pts. who received ARG at 250 mg/250 ml (6.1.06–6.18.06) and 25 pts. who received ARG at 100mg/100ml (6.19.06–7.14.06). In the RF group, 43 pts. received ARG for 292 pt. days with a mean of 6.6 (range, 1–12) pts. treated/day. A total of 134 vials were purchased with a mean of 0.46 vials utilized/pt. day. In the RF group, the total AWP acquisition costs and mean cost/pt. day were $152,626 and $524, respectively. A 12-mo. acquisition cost projection analysis was performed with the following assumptions: 1254 pt. days on ARG (1.1.06–7.14.06); vial use/pt. day: SF group (0.92), RF group (0.46); and the 2006 AWP acquisition cost/vial of ARG. This analysis showed projected 12-mo. acquisition costs of $2,459,374 for the SF group and $1,229,687 for the RF group. The projected annualized cost avoidance in pharmacy 2006 AWP acquisition costs with the RF strategy was $1,229,687/yr. (mean $102,474/mo.).

Conclusions: We conclude that a revised formulation strategy for ARG administration can produce significant cost avoidance in hospital pharmacy AWP acquisition costs. An analysis of patient characteristics and indications for ARG will be presented.