Use of low-molecular-weight heparin during dental extractions in a medicaid population.
BACKGROUND
Evidence-based guidelines recommend against discontinuation of oral anticoagulation therapy during most dental procedures because severe bleeding complications are rare and there is an increased risk for thromboembolic events in patients for whom warfarin therapy is interrupted. Although interruption of oral anticoagulation and bridge therapy with low-molecular- weight heparin (LMWH) may be indicated for high-risk individuals undergoing certain procedures, the use of LMWH in tooth extractions is expensive and often unnecessary.


OBJECTIVE
The purpose of this review was to identify and characterize procedural use of LMWH for dental extractions with respect to current consensus recommendations.


METHODS
The Idaho Medicaid pharmacy and medical claims database was queried to identify patients with a tooth extraction procedure between February 1, 1998, and January 31, 2005. Patients on warfarin therapy for 2 months before tooth extraction were identified as were claims for LMWH within 30 days before the procedure or 5 days after. Patient profiles were reviewed to determine number of extractions, rate of LMWH use, indication for anticoagulation, and associated drug costs.


RESULTS
Of 55,260 Medicaid patients who had a tooth extraction, 518 (0.9%) had received warfarin for at least 2 consecutive months before the tooth extraction procedure. Of these, 31 patients (6%) received LMWH therapy at the time of extraction for a total of 35 procedures. All procedures selected for review carried a low bleeding risk, with an average of 1.3 teeth extracted per procedure. The indications for anticoagulation included 16 procedures (45.7%) involving patients with a history of a thromboembolic event more than 90 days before the procedure, 10 procedures (28.5%) involving patients with a prosthetic valve, 4 procedures (11.4%) involving anticoagulated patients with atrial fibrillation, and 5 procedures (14.2%) involving patients with a history of thromboembolism fewer than 3 months before the procedure. LMWH costs for these 35 extractions totaled $22,294, or an average of $637 per procedure or $474 per extracted tooth. Enoxaparin was used in all but 1 of the procedures, with an average 5-day supply (average 8 enoxaparin units) dispensed per procedure. The costs associated with the required additional drug monitoring, e.g., INR monitoring, were not included in this analysis.


CONCLUSIONS
Although the overall number of dental procedures in anticoagulated patients using LMWH was small in our review, this inappropriate use resulted in avoidable costs to this Medicaid program.
Pettinger
Tracy K
TK
Department of Pharmacy Practice and Administrative Sciences, Idaho State University, Campus Box 8357, Pocatello, ID 83209, USA. tracy@pharmacy.isu.edu
Owens
Christopher T
CT
D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D017723:Drug Utilization Review / Q000379:methods / Q000706:statistics & numerical data; D019317:Evidence-Based Medicine / Q000379:methods / Q000592:standards; D006470:Hemorrhage / Q000209:etiology / Q000517:prevention & control*; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D006801:Humans; D007061:Idaho; D008329:Managed Care Programs / Q000592:standards / Q000706:statistics & numerical data; D008484:Medicaid; D010361:Patients / Q000706:statistics & numerical data; D017410:Practice Guidelines as Topic / Q000592:standards; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014081:Tooth Extraction / Q000009:adverse effects / Q000706:statistics & numerical data*; D014859:Warfarin / Q000008:administration & dosage / Q000627:therapeutic use
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D014859:Warfarin