Treatment With Thyroid Hormone-Reply

In Reply.—  Dr Gaby raises several issues that deserve comment.First, he suggests that desiccated thyroid has medicinal properties beyond those of thyroxine itself, and criticizes my branding desiccated thyroid obsolete. It is ironic that he would consider the large fraction of the iodine in desiccated thyroid existing as diiodotyrosine (or other iodinated compounds) to be an advantage, since such compounds are metabolically inert.¹ Indeed, one of the main reasons for rejecting desiccated thyroid is its lack of standardization and frequent low hormonal content, which often lead to suboptimal therapy. This can be potentially disastrous, especially in patients with thyroid carcinoma. There is absolutely no evidence that desiccated thyroid alleviates symptoms due to hypothyroidism that are not reversed with pure levothyroxine sodium.Second, Dr Gaby suggests that problems such as menstrual irregularity and "idiopathic edema" respond to thyroid hormone therapy, because they may be due to extremely subtle thyroid