Drug use evaluation of sitagliptin dosing by pharmacist versus nonpharmacist clinicians in an internal medicine department of a private physician-owned multispecialty clinic.
BACKGROUND
Sitagliptin is recommended for initial and maintenance dosing at 100 mg daily. Downward dose adjustment is recommended in patients with moderate or severe renal insufficiency.


OBJECTIVE
To determine the prevalence of the potentially inappropriate initial dosing of sitagliptin based on estimated glomerular filtration rate (GFR) at baseline for pharmacist versus nonpharmacist prescribers in an internal medicine department of a private physician-owned multispecialty clinic that included a pharmacist-managed diabetes program.


METHODS
This was a retrospective cross-sectional cohort analysis using data from an electronic medical record database of a private physicianowned multispecialty clinic that included a pharmacist-managed diabetes program. For patients prescribed sitagliptin between October 17, 2006, and June 5, 2008, the variables of interest were (a) the initial sitagliptin dose; (b) the GFR, calculated for each patient using the 4-point Modification of Dosing in Renal Disease (MDRD) formula at the time of initiation of sitagliptin; and (c) whether the clinician initiating the dose was a pharmacist or nonpharmacist (i.e., internal medicine physician, nurse practitioner, or physician assistant).


RESULTS
Of the 290 patients prescribed sitagliptin for the first time between October 17, 2006, and June 5, 2008, 35 (12.1%) received a potentially inappropriate initial dose according to product labeling regarding renal function; 21 were over-dosed and 14 were under-dosed. Potentially inappropriate dosing occurred in 1 of 158 patients (0.6%) who had initial dosing prescribed by a pharmacist compared with 34 of 132 patients (25.8%) for nonpharmacists (P < 0.001, Fisher's exact test).


CONCLUSIONS
Potentially inappropriate initial dosing of sitagliptin based on assessment of renal function was more likely to occur with nonpharmacist prescribers than with a pharmacist prescriber.
McFarland
M Shawn
MS
Alvin C. York Veterans Administration Hospital, 3400 Lebanon Pike, Murfreesboro, TN 37130, USA. Michael.McFarland2@va.gov
Cross
L Brian
LB
Gross
Benjamin
B
Gentry
Chad
C
Tunney
Jeffrey
J
Patel
U P
UP
D000554:Ambulatory Care Facilities; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring / Q000379:methods; D017723:Drug Utilization Review; D005919:Glomerular Filtration Rate; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007677:Kidney Function Tests; D008508:Medication Errors / Q000706:statistics & numerical data; D010595:Pharmacists / Q000458:organization & administration*; D017149:Private Sector; D024382:Professional Role; D011719:Pyrazines / Q000008:administration & dosage*; D051437:Renal Insufficiency / Q000150:complications; D012189:Retrospective Studies; D000068900:Sitagliptin Phosphate; D014230:Triazoles / Q000008:administration & dosage*; D014481:United States
D007004:Hypoglycemic Agents; D011719:Pyrazines; D014230:Triazoles; D000068900:Sitagliptin Phosphate