Generic Drugs

• Generic Info for Consumers/Patients   
  Official FDA document. Good promotional tool. (Need Acrobat Reader to see/print it.)
  
  
• FDA Office of Generic Drugs
  
  
• Generic Pharmaceutical Assn.
  
  
• Top 200 Generic Drugs
  
  
• Patents and Exclusivity - To find out when a particular drug's patent/exclusions expire go to the online Orange Book, where you type in the name of the drug. Then click on the application number to see the patent/exclusivity info.  In the U.S. generally a patent is valid for 17 years.  Patents for some pharmaceutical inventions may be extended by the federal government for up to five years to compensate for pre-marketing delays related to Federal regulatory procedures. Manufacturers file a new drug application (NDA) and must go through tremendous expense to document safety and effectiveness, before receiving approval to market the drug.
  
  
• Bioequivalence - When a company seeks to market a generic drug in the U.S. it must file an abbreviated new drug application (ANDA) with the FDA.  Since safety and efficacy was proven by the company who submitted the original NDA, to gain approval for an ANDA the manufacturer does not have to prove safety and efficacy.  They must, however, document bioequivalence to the innovator drug product with a small study of 24 to 36 subjects.  The FDA says, "Bioequivalence of different formulations of the same drug substance involves equivalence with respect to the rate and extent of drug absorption. Two formulations whose rate and extent of absorption differ by -20%/+25% or less are generally considered bioequivalent. The use of the -20%/+25% rule is based on a medical decision that, for most drugs, a -20%/+25% difference in the concentration of the active ingredient in blood will not be clinically significant."
  
  
• Therapeutic Equivalence   
  Read the FDA's definition.  (Please note that there is some confusion about the term "therapeutic equivalence."  The FDA's usage of the term should be differentiated from the idea of 2 drugs like Zocor and Lipitor being roughly equivalent in effect when used in equivalent doses. Often health care professionals or insurance companies will call this "therapeutic equivalence.")
  
  
• Therapeutic Equivalence Ratings - You can search the Orange Book for the rating code of a particular manufacturer's drug product. Basically, any rating that starts with an "A" is either bioequivalent, or the FDA considers bioequivalence to be irrelevant in the drug's action.  "AB" means bioequivalence has been studied and demonstrated.  It is not a lower rating than "AA". The ratings AA, AN, AO, and AP do not require bioequivalence studies, because the FDA believes them to be unnecessary.  Drug products for which actual or potential bioequivalence problems have not been resolved by adequate evidence of bioequivalence are rated "B". Often the problem is with specific dosage forms rather than with the active ingredients. These are designated BC, BD, BE, BN, BP, BR, BS, BT, BX, or B*.  Want to know more?  Read the FDA's official definitions of generic rating codes. (Not short.)
  
  
• Generics for "Narrow Therapeutic Index" Drugs  FDA letter to practitioners about digoxin, theophylline, carbamazepine, etc. (L-thyroxine is different.) 
  List of Narrow Therapeutic Index Drugs
  Go to the last page of the document to see NTIs.
  
  
• Another FDA letter on generics for Narrow Therapeutic Index Drugs This one is to NABP.
  
  
• AMA is still against generic substitution!!!!???  
  
  
• Did you know that lawsuits as a result of generic substitution are comparatively quite rare? And if a problem were to arise, many generics companies will defend you in court and pay any judgment related to your dispensing their products.  Especially when you choose A rated generics, you are on solid ground.