Endocrine Abstracts

This is 66 year old lady was referred by GP for Abnormal TFT. Her TFT was done routinely and showed TSH-2.7, FT4-9.8. Patient did not have symptoms of hypothyroidism, or did not have any weight gain. On examination, thyroid was not enlarged. In view of Low FT4, she was started on Levothyroxine 25 mcg once daily. After taking the medications she felt warm and unsteady and noticed tremour on both hands. The repeat TFT came back as normal. TSH-2.9, FT4-14.2\. In view of pts symptoms the thyroxine was stopped. Repeat TFT showed normal TSH and low FT4. Looking back at her TFT over the last few years it has shown normal TSH and low FT4. No previous thyroid problems She is known to have epilepsy and hypertension. She is on Lamotrigine, Carbamazepine, Amlodipine and bendroflumethiazide.

Questions: 1) Is this low FT4 secondary to Carbamzepine?

2) How to manage this case?