The Therapeutic Equivalence of Generic Drugs

• (8/9/2005) Therapeutic Equivalence between Levothyroxine Sodium drug products.  Because there are multiple reference listed drugs of levothyroxine sodium tablets and some reference listed drugs' sponsors have conducted studies to establish their drugs' therapeutic equivalence to other reference listed drugs, FDA has determined that its usual practice of assigning two or three character TE codes may be potentially confusing and inadequate for these drug products. Accordingly, FDA provides the following explanation and chart of therapeutic equivalence evaluations for levothyroxine sodium drug products. See Annual Edition (PDF - 22 MB). Select Bookmark 1.8 Description of Special Situations for a complete explanation of the therapeutic equivalencies and chart.
  
  
• Therapeutic Equivalence of Generic Drugs Letter to Health Practitioners (2/4/1998) This letter addresses therapeutic equivalence between generic and innovator drug products.
  
• Therapeutic Equivalence of Generic Drugs Response to National Association of Boards of Pharmacy (2/6/1998) This letter provides background information, and answers to questions on narrow therapeutic drugs and their substitutability.
  
• Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) The Orange Book lists approved drug products that are bioequivalent, including new drugs, generic drugs, and antibiotics. Approved nonprescription products are also in the Orange Book along with information about patents and periods of marketing exclusivity.