I have been having problems of low t3 since the start of the therapy. FT4 seemed ok but T3 and FT3 were always low. TSH also low sometimes. Now, when I look back, it comes to me that my problems with the thyroid started at the same time as the first asthma attacks. I was put on a corticoseroid which I have been using since last year. Yesterday I read an article about the conversion problems;
" Euthyroid sick syndrome and/or medication effect. When the TSH level is low secondary to euthyroid sick syndrome or a drug, or both, the free T3 level is usually found to be also low, which may be solely related to a component of euthyroid sick syndrome or secondary to the drugs themselves, as drugs such as corticosteroids and amiodarone inhibit the conversion of T4 to T3"