docket number 2003P-0387From: Jerome Hershman [jhershmn@ucla.edu]
Sent: Sunday, November 23, 2003 9:47 PM
To: fdadockets@oc.fda.gov
Subject: docket number 2003P-0387

Dockets Management Branch
US Food and Drug Administration
5630 Fishers Lane, Room 1061 HFA-305
Rockville, MD 20852


Dear Sirs:


        I wish to comment on your procedure for determining bioequivalence of levothyroxine products. Your current procedure is deficient and cannot recognize differences of 12.5% in bioequivalence. As a specialist in management of patients with thyroid disease, I wish to emphasize that differences of this magnitude can result in over-treatment or under-treatment of patients with significant clinical consequences. Because of this, it is essential for patients to be maintained on a single brand of levothyroxine. I believe that Abbott Laboratories has petitioned you to reconsider the technology for bioequivalence of levothyroxine. Clinical studies in hypothyroid patients, using TSH as an endpoint would be most desirable.


        Please note that I am a Past-President of the American Thyroid Association. I believe that my opinion is representative of that of other thyroid disease specialists.


        Sincerely,


        Jerome Hershman




-- 
Professor of Medicine
UCLA School of Medicine
Endocrinology and Diabetes Division-111D
VA Greater Los Angeles Healthcare System
11301 Wilshire Blvd
Los Angeles, CA 90073