A Patient Is Started on Levothyroxine (Synthroid)50 Mcg Daily

Multiple Choice

A patient is started on levothyroxine (Synthroid) 50 mcg daily.Which laboratory result should a nurse identify as an indication that this treatment is effective?

A) Free triiodothyronine (T3) decreases.
B) Free thyroxine (FT4) decreases.
C) Thyroid-stimulating hormone (TSH) level decreases.
D) Total thyroxine (T4) decreases.