For a patient diagnosed with hypothyroidism, which medication is least likely to be tolerated?

In the case of a patient diagnosed with hypothyroidism, the medication least likely to be tolerated is Liothyronine. This medication contains only the active thyroid hormone T3 and is typically used when a rapid response is needed or when a patient has difficulty converting T4 (the inactive form) to T3. However, patients may experience more side effects with Liothyronine, including increased heart rate, anxiety, and jitteriness, due to its more potent physiological effects compared to Levothyroxine, which is T4.

Levothyroxine is often the first-line treatment for hypothyroidism since it mimics the body’s natural thyroid hormone levels more closely and typically has a better side effect profile. Liotrix is a combination of T4 and T3, and while it may have a broader action than Levothyroxine alone, it is still generally well tolerated. Propylthiouracil is actually an antithyroid medication used to treat hyperthyroidism rather than hypothyroidism, making it irrelevant in this context.

Thus, Liothyronine's increased potency and risks of side effects lead to a lower tolerance in patients, especially when compared to the other medications typically used in hypothyroidism management.