Liothyronine Sodium Teva (Liothyronine Sodium)

Liothyronine sodium is used in thyroid‑related disorders to restore normal hormone levels.

• Hypothyroidism: restores deficient thyroid hormone, improving metabolic function and symptoms.
• Myxedema coma: provides rapid hormone replacement critical for life‑threatening situations.
• Inadequate response to levothyroxine (T4) therapy: augments hormone levels when T4 alone does not achieve euthyroidism.

• Liothyronine sodium is a synthetic form of triiodothyronine (T3) that binds to nuclear thyroid hormone receptors (TRα and TRβ). Receptor activation modulates gene transcription, increasing the expression of proteins that regulate basal metabolic rate, oxygen consumption, and carbohydrate, lipid, and protein metabolism, thereby mimicking the physiological actions of endogenous T3. The increased transcription leads to enhanced mitochondrial activity and up‑regulation of Na⁺/K⁺‑ATPase, contributing to the overall rise in metabolic rate.

Liothyronine sodium may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Palpitations: rapid or irregular heartbeat sensations.
• Nervousness or anxiety: heightened nervous system activity.
• Tremor: fine shaking of hands or limbs.
• Heat intolerance: excessive sweating and feeling overly warm.
• Insomnia: difficulty falling or staying asleep.

Serious or Rare Side Effects

• Cardiac arrhythmia: potentially life‑threatening irregular heart rhythm.
• Angina pectoris: chest pain due to reduced coronary blood flow.
• Myocardial infarction: heart attack risk, especially in susceptible patients.
• Atrial fibrillation: rapid irregular atrial rhythm.
• Severe osteoporosis: accelerated bone loss with long‑term use.
• Anaphylactic reaction: severe allergic response requiring immediate medical attention.

Before initiating liothyronine sodium therapy, clinicians should consider several safety precautions.

• Monitor thyroid function tests: adjust dose based on serum T3/T4 levels.
• Assess cardiovascular status: avoid in uncontrolled heart disease or recent myocardial infarction.
• Use caution in diabetes: thyroid hormone may affect glucose control.
• Evaluate adrenal insufficiency: ensure adequate glucocorticoid coverage before starting.
• Discuss pregnancy and lactation: weigh potential risks with a healthcare provider.
• Store at room temperature: keep in the original container, protect from moisture and light.

Liothyronine sodium can interact with other medicines, altering its effectiveness or safety.

Major Interactions (Avoid)

• Antithyroid drugs (e.g., propylthiouracil, methimazole): block thyroid hormone action.
• Beta‑blockers: may mask symptoms of excess thyroid hormone.
• Digoxin: increased risk of toxicity due to heightened cardiac activity.

Moderate Interactions (Monitor Closely)

• Oral contraceptives containing estrogen: raise thyroid‑binding globulin, reducing free hormone.
• Calcium or iron supplements: decrease liothyronine absorption if taken simultaneously.