Case Reports of Three Hypothyroid Patients Requiring Very High Doses of Levothyroxine

Abstract

Majority of hypothyroid patients achieve and maintain euthyroidism on doses of levothyroxine in the range of 100 to 200 ug per day. This is a report of three patients with hypothyroidism requiring 300 - 450 ug of levothyroxine daily to be euthyroid. These comprised one case of central and two cases of primary hypothyroidism. Contributory factors to high doses of levothyroxine in the patients include use of efavirenz in one patient, morbid obesity and cimetidine therapy in another patient and sodium valproate treatment in the third patient. High doses of levothyroxine may be required to achieve euthyroidism in patients receiving efavirenz, sodium valproate and cimetidine.




J Med Cases. 2014;5(8):452-454
doi: http://dx.doi.org/10.14740/jmc1822w