Effect of dabigatran on referrals to and switching from warfarin in two academic anticoagulation management services

Dabigatran was expected to replace warfarin for stroke prevention in patients with nonvalvular atrial fibrillation (AF) who are warfarin naive, difficult to maintain in therapeutic range, or at risk of warfarin-related bleeding complications. We hypothesized that the number of patients with nonvalvular AF referred to Anticoagulation Management Services would decrease sharply and that most would switch from warfarin to dabigatran. We evaluated the number of patients with nonvalvular AF referred to 2 large services, Anticoagulation Management Service 1 and Anticoagulation Management Service 2, 12 months before and after market entry of dabigatran. We also evaluated the number of patients who switched from warfarin to dabigatran. Anticoagulation Management Service 1 follows 1,225 patients with nonvalvular AF with mean CHADS₂ and CHA₂DS₂-VASc scores of 2.0 and 3.5, respectively. Anticoagulation Management Service 2 follows 1,137 patients with nonvalvular AF with mean CHADS₂ and CHA₂DS₂-VASc scores of 2.0 and 3.3, respectively. In the 12 months preceding market entry of dabigatran, patients with nonvalvular AF constituted 537 (31.4%) of the referrals sent to Anticoagulation Management Service 1 and increased to 793 (32.3%) in the following 12 months. For Anticoagulation Management Service 2, patients with nonvalvular AF constituted 617 (30.7%) of referrals before market entry of dabigatran and decreased to 495 (25.2%) of referrals. Eighty-one patients (6.6%) from Anticoagulation Management Service 1 and 44 (3.9%) from Anticoagulation Management Service 2 have switched from warfarin to dabigatran. The frequency of initial prescription of dabigatran for stroke prevention in AF and the frequency of transition from warfarin to dabigatran have been less than expected.

Efficacy and safety of novel anticoagulants compared with established agents

Dabigatran, rivaroxaban, and apixaban are novel oral anticoagulants that offer major advantages over existing agents. The onset of the anticoagulant effect of these agents is rapid. Each agent has a predictable anticoagulant response that eliminates the need for monitoring. Clinical trials have been completed with all three agents in the prevention and treatment of the three leading causes of cardiovascular death: myocardial infarction, stroke, and venous thromboembolism (VTE). Novel agents have shown reduced or similar rates of thrombosis, major bleeding, and adverse events when weighed against either low molecular weight heparin or warfarin. Additional trials are underway and more agents are in development. As a result, novel anticoagulants may impact physician prescribing practices and warrant consideration in patients requiring thrombosis management.

Digoxin: clinical highlights: a review of digoxin and its use in contemporary medicine

Digoxin is the oldest cardiac medication used in contemporary medicine. With a complex pharmacokinetic profile and narrow therapeutic index, its use in managing patients with atrial arrhythmias or heart failure can present a challenge to today's clinicians. Digoxin dosing based on patient-specific factors such as age, lean body weight, and renal function will allow practitioners to minimize drug toxicity while maintaining clinical efficacy. The ability to recognize digoxin overdose, which can manifest in both the acute and chronic settings, helps guide the appropriate dosing of digoxin immune globulins to reverse toxicity. Understanding this unique medication is essential for clinicians to ensure digoxin is used safely and effectively in practice.

The signature of supernova ejecta in the X-ray afterglow of the gamma-ray burst 011211

Now that gamma-ray bursts (GRBs) have been determined to lie at cosmological distances, their isotropic burst energies are estimated to be as high as 1054 erg (ref. 2), making them the most energetic phenomena in the Universe. The nature of the progenitors responsible for the bursts remains, however, elusive. The favoured models range from the merger of two neutron stars in a binary system to the collapse of a massive star. Spectroscopic studies of the afterglow emission could reveal details of the environment of the burst, by indicating the elements present, the speed of the outflow and an estimate of the temperature. Here we report an X-ray spectrum of the afterglow of GRB011211, which shows emission lines of magnesium, silicon, sulphur, argon, calcium and possibly nickel, arising in metal-enriched material with an outflow velocity of the order of one-tenth the speed of light. These observations strongly favour models where a supernova explosion from a massive stellar progenitor precedes the burst event and is responsible for the outflowing matter.