Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: Generic substitution policies are financially attractive.1 Although several studies have found no clinically important effects of switching to generic warfarin formulations,2 some observational studies have found an increase in warfarin dosages3 or frequent and substantial changes in international normalized ratio (INR).4 Few studies have been sufficiently large to examine clinical outcomes, and none have done so in a large-population setting.
Paterson JM, Mamdani M, Juurlink DN, Naglie G, Laupacis A, Stukel TA. Clinical Consequences of Generic Warfarin Substitution: An Ecological Study. JAMA. 2006;296(16):1966-1972. doi:10.1001/jama.296.16.1969-b