Pharmacy & Therapeutics - September 2008 - (Page 515)

NEW DRUGS compression stockings group, was accounted for by four hemarthroses of less than 300 mL of blood each. (Source: Ann Intern Med 2008;149:73– 82.) DRUG NEWS mum oxytocin ranges above 20 mU/ minute increased the risk fourfold or greater. (Source: Am J Obstet Gynecol 2008;199: 32.e1–32.e5.) Heparin-Induced Thrombocytopenia—or Is It? Case scenario: The patient seemingly has heparin-induced thrombocytopenia (HIT) but hasn’t been taking heparin. If it isn’t a drug reaction, what is it? Researchers from Canada believe they have evidence suggesting an autoimmune component. They reported on three patients with apparent HIT. Two patients presented with thrombocytopenia and thrombosis, with events typical of HIT: limb artery thrombosis, stroke, and venous thromboembolism. One patient died, and the other had a debilitating stroke and limb amputation. The third patient, who did not have thrombocytopenia or thrombosis, experienced anaphylactic reactions on two occasions shortly after receiving two injections of low-molecular-weight heparin (LMWH), with an associated drop in platelet count. All three patients had high levels of platelet-activating antiPF4/heparin antibodies of the immunoglobulin G class at presentation despite no previous heparin exposure. Each patient had a serological profile characteristic of HIT, with strong positive test results from three different assays. HIT has several features consistent with an autoimmune pathogenesis: the antibodies bind to PF4, a self-protein. The role of pharmacological heparin in producing antigenic modifications on PF4 can be substituted for by endogenous heparin or chondroitin sulfate. Patients with delayed-onset HIT develop thrombocytopenia and thrombosis beginning several days after all heparin has been stopped. Sera from such patients contain antibodies that cause substantial platelet activation even in the absence of heparin. Intriguingly, the researchers add, all three patients had infectious or inflammatory events during the two-week interval preceding their acute illness. (Source: Am J Med 2008;121:632–636.) Are Drug-Eluting Stents Safe for Diabetic Patients? Noting that the enthusiasm for drugeluting stents has been dampened somewhat by data showing higher rates of late stent thrombosis and possibly higher rates of myocardial infarction (MI) and death, researchers from Ontario, Canada, set out to address “an important gap in knowledge.” Although their group had already demonstrated the safety of the stents in a large population-based cohort, they had not assessed the safety in diabetic patients. In this large study, the investigators compared bare-metal stents with drugeluting stents in 3,959 patients with diabetes and in 9,394 patients without diabetes. They found that the coated stents halved the incidence of repeated target-vessel revascularization in diabetic patients (at two years, 7% vs. 14%, respectively). Overall, the rates of MI did not differ significantly: 6.6% with drugcoated stents and 4.5% with bare-metal stents. Another key finding was that mortality rates among diabetic patients with the coated stents (7.6%) were not significantly higher than among patients treated with bare-metal stents (9.5%). Mortality rates were also significantly lower among nondiabetic patients receiving drug-eluting stents. (Source: Am Heart J 2008;156:125– 134.) Flurbiprofen Reduces Lumpectomy Pain A pre-emptive injection of flurbiprofen axetil, a nonsteroidal anti-inflammatory drug (NSAID), may ease the postoperative pain of a lumpectomy, according to a study at Nanjing Medical University, China. Flurbiprofen is used to relieve pain and inflammation. The staff gave 99 women an IV injection of 50 mg flurbiprofen 15 minutes before the operation began and 15 minutes before it ended; 97 women received a saline placebo. The women in the flurbiprofen group had significantly lower pain scores, used less morphine, and rated their overall satisfaction higher. The researchers found no significant difference in side effects. (Source: Acute Pain 2008;10:65–71.) Oxytocin and Uterine Rupture To avoid the high risk of uterine rupture during a vaginal delivery, physicians should administer oxytocin at a dose of no more than 20 mU/minute when a woman has had a previous cesarean delivery. The higher the dose and longer the duration of the oxytocin, the greater the chance of uterine rupture. Researchers from Washington University School of Medicine in St. Louis conducted a nested case–control study within a multicenter study of more than 25,000 women with at least one prior cesarean birth. Of the 804 women in the case–control study, 272 were exposed to oxytocin and 62 of those had uterine rupture. The dose range of 6 to 20 mU/ minute tripled the risk of rupture. Maxi- Femoral Analgesia Helps Prevent Delirium after Surgery Peripheral regional analgesia can help prevent postoperative delirium in elderly patients, according to a retrospective Vol. 33 No. 9 • September 2008 • P&T® 515

Table of Contents Feed for the Digital Edition of Pharmacy & Therapeutics - September 2008

Pharmacy & Therapeutics - September 2008 Contents Editorial Medication Errors Prescription: Washington New Drugs/Drug News/New Medical Devices Drug Forecast Effect of Prescription Copays on Adherence and Treatment Failure with Oral Antidiabetic Medications Vaccine Declinations Present New Challenges for Public Health Universal Health Care in America Digestive Disease Week and American Diabetes Association Pharmaceutical Approval Update

Pharmacy & Therapeutics - September 2008

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