Reclast® medication & Warfarin

Reclast® prescription medication, or zoledronic acid, manufactured by Novartis, received U.S. Federal Drug Administration (FDA) approval in August, 2007 as the first once-a-year treatment for postmenopausal osteoporosis.1 Women are four more times at risk for osteoporosis than men and the most frequent users of bone density medications.2

A three-year Reclast® medication study versus placebo demonstrated a 70% reduction of vertebral fractures, a 41% reduction in hip factures and a significant improvement in bone density. There was a slightly higher incidence of atrial fibrillation in the study group (2.4%) versus 1.9% in the control group.This suggests the incidences of developing atrial fibrillation were not related to the acute infusions.1

The Novartis package insert for Reclast® does not include a drug-to-drug interaction between Reclast and warfarin. Adverse reactions to Reclast did included flu-like symptoms, headache, fever, hypocalcemia, among others, but these were not associated with warfarin use.1

If maintaining bone density and preventing osteoporosis is a priority, choose a medication that works safely while taking warfarin. A discussion between doctor and patient is important before considering Reclast therapy. Patients on warfarin may react differently to the Reclast 15 minute, once-a-year injection.

More frequent International Normalized Ratio (INR) testing may be required, especially in the early weeks following a Reclast® medication injection. Warfarin labeling additionally recommends more frequent testing for any newly started or recently stopped medications.3

Home INR monitoring can provide an easy, practical means of determining INRs in the privacy of a patient’s home, and help identify early drug interactions with warfarin.

  1. Novartis, 2010 Web site: www.reclast.com Retrieved: February 10, 2010.
  2. National Osteoporosis Foundation, 2008.
  3. Bristol-Myers Squibb Company. Medication Guide for Coumadin Tablets and Coumadin for Injection [Package Insert]. Princeton, NJ: Bristol-Myers Squibb Company, 2009.