Many patients ask their physicians whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamin supplements.

Balfaxar (Octapharma), a human plasma-derived four-factor prothrombin complex concentrate (PCC), has been approved by the FDA for rapid reversal of warfarin anticoagulation in adults who require an urgent surgical/invasive procedure. It is the second four-factor PCC to become available in the US; Kcentra, which has been available since 2013, is approved for the same indication and for urgent reversal of warfarin anticoagulation in adults with acute major bleeding. Balfaxar is marketed in Canada and Europe as Octaplex.

Warfarin-related bleeding, especially intracranial hemorrhage, can be catastrophic. Several products are available to reverse warfarin’s anticoagulant effect.

Many patients ask their healthcare providers whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamins.

Cataracts are the leading cause of blindness worldwide because cataract surgery is not available to most people in developing countries.

The FDA has approved use of Kcentra (CSL Behring), a human-derived 4-factor prothrombin complex concentrate (PCC), for urgent reversal of warfarin anticoagulation in adults with acute major bleeding. It is the only 4-factor PCC available in the US.

Anticoagulants are the drugs of choice for treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), collectively referred to as venous thromboembolism (VTE).

Atrial fibrillation increases the risk of stroke by a factor of 5. A randomized controlled trial (ACTIVE W) in 6706 patients with atrial fibrillation and one or more additional risk factors (≥75 years old; hypertension; previous stroke, transient ischemic attack or non- CNS embolus; left ventricular ejection fraction <45%; peripheral vascular disease; or 55-74 years old plus diabetes or coronary artery disease) found that a vitamin K antagonist such as warfarin (Coumadin, and others) was superior to clopidogrel (Plavix) plus aspirin in preventing vascular events, especially ischemic...

A reader expressed disappointment that our recent listing of “Some Warfarin Drug Interactions”1 did not include acetaminophen. Perhaps it should have. Acetaminophen can increase the anticoagulant effect of warfarin, particularly with continued use, but it does so inconsistently. The mechanism of this interaction has not been established, but may be related to an acetaminophen metabolite inhibiting vitamin K-epoxide reductase, the target for warfarin’s anticoagulant effect.2Patient susceptibility varies, possibly on a genetic basis; occasional use of acetaminophen generally has little or...

Warfarin sodium (Coumadin, and others) and other coumarin anticoagulants prevent thrombosis, but patient response is highly variable and overanticoagulation can lead to hemorrhage. Genotyping patients for single nucleotide polymorphisms (SNPs) that affect coumarin metabolism and sensitivity may help clinicians estimate the therapeutic warfarin dose. The FDA has added a note to warfarin labeling recommending lowrange doses for patients with such genetic variations. Commercial tests for these variants are now available and cost about $500 per test.