A hypothyroid patient’s annual lab work shows low thyroid-stimulating hormone (TSH) levels (0.20 mU/L). Her free triiodothyronine and free thyroxine levels are both in the middle of the normal range. Should her levothyroxine (Synthroid) dose (100 µg/day) be changed?
—Judy Lemons, PA-C, BSPA, Lakeside City, Tex.
I would lower the dose of the replacement hormone because overcorrection (as manifested by the excessively suppressed TSH) can lead to cardiac dysrhythmias (especially atrial fibrillation), as well as accelerated bone loss.—Reuben W. Zimmerman, PA-C (121-1)