Liothyronine Sodium (3 brand names, 2 dosage forms, 2 routes)
Available dosage forms: TABLET, INJECTABLE.
Routes of administration: ORAL, INJECTION.
Brand Names
- CYTOMEL
- LIOTHYRONINE SODIUM
- TRIOSTAT
Related Health Topics
Boxed Warning
• Thyroid hormones, including LIOTHYRONINE SODIUM, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss. • 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 [see Adverse Reactions (6), Drug Interactions (7.7), and Overdosage (10)].
Contraindications
Liothyronine sodium is contraindicated in patients with uncorrected adrenal insufficiency [see Warnings and Precautions (5.3)].
Adverse Reactions
Adverse reactions associated with liothyronine sodium therapy are primarily those of hyperthyroidism due to therapeutic overdosage [see Warnings and Precautions (5.4) and Overdosage (10)]. They include the following: General: fatigue, increased appetite, weight loss, heat intolerance, fever, excessive sweating Central nervous system: headache, hyperactivity, nervousness, anxiety, irritability, emotional lability, insomnia Musculoskeletal: tremors, muscle weakness and cramps Cardiovascular: palpitations, tachycardia, arrhythmias, increased pulse and blood pressure, heart failure, angina, myocardial infarction, cardiac arrest Respiratory: dyspnea Gastrointestinal: diarrhea, vomiting, abdominal cramps, elevations in liver function tests Dermatologic: hair loss, flushing Endocrine: decreased bone mineral density Reproductive: menstrual irregularities, impaired fertility
Mechanism of Action
Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis. Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA. This hormone nuclear receptor complex activates gene transcription and synthesis of messenger RNA and cytoplasmic proteins. The physiological actions of thyroid hormones are produced predominantly by T3, the majority of which (approximately 80%) is derived from T4 by deiodination in peripheral tissues.
Overdosage
The signs and symptoms of overdosage are those of hyperthyroidism [see Warnings and Precautions (5.4) and Adverse Reactions (6)]. In addition, confusion and disorientation may occur. Cerebral embolism, seizure, shock, coma, and death have been reported. Symptoms may not necessarily be evident or may not appear until several days after ingestion. Reduce the liothyronine sodium dose or temporarily discontinued if signs or symptoms of overdosage occur. Initiate appropriate supportive treatment as dictated by the patient’s medical status. For current information on the management of poisoning or overdosage, contact the National Poison Control Center at 1-800-222-1222 or www.poison.org.