In the treatment of hypothyroidism, thyroxine is preferred over liothyronine because thyroxine:
High-Yield Explanation
(Ref: KDT 6/e p247) Liothyronine (T3) as compared to thyroxine (T4) is: Fast acting More potent Sho half life Indication of liothyronine includes myxedema coma and for most of the indications thyroxine is used because is has a long half life thus can be used less frequently than T3.