Coagulation Counseling

Pharmacists Can Improve Outcomes in VTE

In the fall of 2008, the Office of theSurgeon General issued a call for a coordinated,multifaceted plan to reduce the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) in the United States. When they occur together, DVT and PE are known as venous thromboembolism (VTE). Pharmacists who are up-to-date on the treatment and prevention of thromboembolic disorders have a tremendous opportunity to educate patients and other health care providers about these conditions, regardless of the setting in which they practice.

Hospital pharmacists can help identify patients at risk for VTE by participating in an institutional screening program, reviewing physician orders to make sure= that DVT prophylaxis has been instituted in high-risk patients, and participating in anticoagulant dosing recommendations. There are numerous published reports of improved outcomes with pharmacist involvement in these types of services. Hospitals with pharmacist managedheparin services reported significantly lower mortality rates and shorter lengths of stay. Medicare costs, bleeding complications, and the percentage of patients requiring transfusions were also lower in hospitals with this service.

The benefits of pharmacist-run anticoagulation clinics in the ambulatory care setting are long-established. Patients who have anticoagulation therapy managed in pharmacist-run clinics spend more time in the therapeutic range and experience better outcomes compared with usualmedical care. Pharmacists in the community setting can also educate patients to use self-testing and self-management, teach proper injection technique for injectable anticoagulants, and educate patients about drug—drug and drug–food interactions.

Recommendations from professional and governmental organizations are driving increased prevention and treatment of VTE. Well-trained pharmacists are an invaluable source of education and anticoagulation therapy management for the US health care system.

Evidence Does Not Support Antithrombotic Therapy for Recurrent Miscarriage

Recurrent miscarriage occurs in about 5% of women. The cause of these events is never identified in about one half of cases. The most common reason for miscarriage is genetic defects in the fetus, but clotting disorders (antiphospholipid syndrome [APS] and inherited thrombophilias) are suspected in some cases. In APS, clots form in the placenta, resulting in fetal demise. Antithrombotic therapy is sometimes used prophylactically for women in whom this condition is suspected, but data supporting this approach are lacking.

Dutch investigators studied a group of 364 women with a history of 2 or more unexplained miscarriages who were either attempting to conceive or were pregnant (≤6 weeks gestation). Patients were assigned to receive low-dose aspirin (80 mg) plus nadroparin (a low-molecular-weight heparin), aspirin alone, or placebo. The live birth rate was 54% in the study, with no significant differences among the groups.

An algorithm to assist in the appropriate selection of antithrombotic therapy in patients with coronary artery stents and atrial fibrillation was recently published in Circulation.

Based on a review of the literature, the authors recommended dual antiplatelet therapy (aspirin and clopidogrel) for patients who are at low risk of stroke. This group includes patients with a CHADS₂ score of 0 to 1, or patients who are at risk for stroke but have a very high risk of bleeding related to advanced age, renal failure, recent gastrointestinal (GI) bleeding, previous stroke, or uncontrolled hypertension. Triple antithrombotic therapy (warfarin, aspirin, clopidogrel) is recommended for patients with a CHADS₂ score of >1 who are not at increased risk of bleeding. If triple antithrombotic therapy is used, it should be limited to 1 month in patients with a bare-metal stent, 3 months for those with a sirolimus stent, and 6 months forthose with a paclitaxel stent. Clopidogrel can be discontinued after this duration of therapy.

Strategies to minimize bleeding risk in patients who are receiving antithrombotic therapy include the use of low-dose aspirin, the addition of an acid-suppressing agent to decrease the risk of GI bleeding, and maintenance of the international normalized ratio in the appropriate range. Given the recent FDA warnings regarding use of proton pump inhibitors with clopidogrel, use of famotidine or ranitidine for acid suppression may be more appropriate for this patient population. PT

Dr. Garrett is manager of the Health Education Center atMission Hospitals in Asheville, North Carolina. Coagulation Counseling