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The Next NTI Controversy: Antiarrhythmic Agents


After several years of watching pharmaceutical companies spar over the therapeutic equivalency of warfarin products, pharmacists—especially those involved with formulary systems—will not be happy to hear that another “narrow therapeutic index” (NTI) controversy is brewing. But in fact, generic substitution of several antiarrhythmic agents has been associated with clinical problems and patient deaths.


Reiffel JA, Kowey PR. Generic antiarrhythmics are not therapeutically equivalent for the treatment of tachyarrhythmias [brief report]. Am J Cardiol. 2000;85:1151–3.