Liothyronine Sodium

BOXED WARNING Drugs with thyroid hormone activity, alone or together with other therapeutic agents, have been used for the treatment of obesity. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects.

WARNINGS The use of thyroid hormones in the therapy of obesity, alone or combined with other drugs, is unjustified and has been shown to be ineffective. Neither is their use justified for the treatment of male or female infertility unless this condition is accompanied by hypothyroidism. Thyroid hormones should be used with great caution in a number of circumstances where the integrity of the cardiovascular system, particularly the coronary arteries, is suspect. These include patients with angina pectoris or the elderly, in whom there is a greater likelihood of occult cardiac disease. Therefore, in patients with compromised cardiac function, use thyroid hormones in conjunction with careful cardiac monitoring. Although the specific dosage of liothyronine sodium injection (T 3 ) depends upon individual circumstances, in patients with known or suspected cardiovascular disease the extremely rapid onset of action of liothyronine sodium injection (T 3 ) may warrant initiating therapy at a dose of 10 mcg to 20 mcg. (See DOSAGE AND ADMINISTRATION .) Myxedematous patients are very sensitive to thyroid hormones; dosage should be started at a low level and increased gradually as acute changes may precipitate adverse cardiovascular events. Severe and prolonged hypothyroidism can lead to a decreased level of adrenocortical activity commensurate with the lowered metabolic state. When thyroid replacement therapy is administered, the metabolism increases at a greater rate than adrenocortical activity. This can precipitate adrenocortical insufficiency. Therefore, in severe and prolonged hypothyroidism, supplemental adrenocortical steroids may be necessary. In rare instances, the administration of thyroid hormone may precipitate a hyperthyroid state or may aggravate existing hyperthyroidism. Extreme caution is advised when administering thyroid hormones with digitalis or vasopressors. (See PRECAUTIONS-Drug Interactions .) Fluid therapy should be administered with great care to prevent cardiac decompensation. (See PRECAUTIONS-Adjunctive Therapy .)

ADVERSE REACTIONS The most frequently reported adverse events were arrhythmia (6% of patients) and tachycardia (3%). Cardiopulmonary arrest, hypotension and myocardial infarction occurred in approximately 2% of patients. The following events occurred in approximately 1% or fewer of patients: angina, congestive heart failure, fever, hypertension, phlebitis and twitching. In rare instances, allergic skin reactions have been reported with liothyronine sodium tablets.