GENERIC WARFARIN A SAFE SUBSTITUTE
A new analysis suggests that substitutionof generic warfarin for brand-namewarfarin (Coumadin, Bristol-MyersSquibb) has no appreciable effect onrates of international normalized ratio(INR) testing or hospitalization for adverseevents. A recent Canadian publicationexamined the effects of a mandatedswitch to the generic product in 2001.The authors examined all warfarin prescriptionsin the 40 months before thepolicy was put in place, during the monthin which the policy came into effect, andin the 9 months after the implementationof the policy. They also checked for drugsthat might affect outcomes in patientsalso taking warfarin.
After the switch to generic warfarin,the authors saw no change in rates ofINR testing or in hospitalizations formajor hemorrhage or cerebral thromboembolism,even after adjusting for useof other drugs that affect coagulation.These results may help overcome lingeringfears on the part of health care professionalswho still have concerns aboutswitching narrow therapeutic indexdrugs to generic products.
Dr. Garrett is a clinical pharmacistpractitioner at Cornerstone HealthCare in High Point, NC.