Liothyronine Sodium Sigmapharm Laboratories International (Liothyronine Sodium)

Liothyronine Sodium is a synthetic thyroid hormone that acts on the hypothalamic‑pituitary‑thyroid axis to restore normal metabolic function.

• Hypothyroidism: restores circulating T3 levels and improves symptoms of low thyroid activity.
• Myxedema coma: provides rapid thyroid hormone replacement in life‑threatening deficiency.
• Thyroid hormone replacement: maintains euthyroid status in patients undergoing thyroidectomy or radioactive iodine therapy.

• Liothyronine Sodium is a synthetic form of triiodothyronine (T3) that enters cells and binds nuclear thyroid hormone receptors. This receptor activation modulates gene transcription, increasing the expression of proteins that raise basal metabolic rate, enhance oxygen consumption, and influence growth and development pathways throughout the body.

Adverse reactions may occur with liothyronine therapy and should be monitored.

Common Side Effects

• Palpitations: sensation of rapid or irregular heartbeat.
• Tachycardia: elevated resting heart rate.
• Insomnia: difficulty falling or staying asleep.
• Heat intolerance: excessive sweating and feeling overly warm.
• Anxiety or nervousness: heightened emotional response.
• Weight loss: unintended reduction in body weight.

Serious or Rare Side Effects

• Cardiac arrhythmias: abnormal heart rhythms that may be life‑threatening.
• Angina pectoris: chest pain due to reduced coronary blood flow.
• Myocardial infarction: heart attack risk in susceptible individuals.
• Severe hyperthyroidism: signs of over‑replacement such as tremor and severe weight loss.
• Bone loss: accelerated osteoporosis with long‑term excess.
• Allergic reactions: rash, pruritus, or anaphylaxis in rare cases.

Liothyronine Sodium requires careful clinical monitoring to avoid over‑ or under‑replacement.

• Thyroid function monitoring: check serum TSH and free T3/T4 levels regularly.
• Cardiovascular disease: adjust dose cautiously in patients with heart disease or arrhythmias.
• Elderly patients: start with lower doses and titrate slowly.
• Adrenal insufficiency: ensure adequate glucocorticoid replacement before initiating therapy.
• Pregnancy and lactation: use only if clearly needed; benefits must outweigh potential risks.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Liothyronine Sodium can alter the effects of several concomitant medications.

Major Interactions (Avoid)

• Antithyroid drugs (e.g., methimazole, propylthiouracil): block the intended hormone effect.
• High‑dose glucocorticoids: may reduce peripheral conversion of T4 to T3, diminishing efficacy.
• Warfarin: thyroid hormone can enhance anticoagulant effect, increasing bleeding risk.

Moderate Interactions (Monitor Closely)

• Estrogen‑containing oral contraceptives: increase thyroid‑binding globulin, potentially altering hormone levels.
• Digoxin: excess thyroid hormone may increase digoxin toxicity.
• Statins: monitor lipid profile as thyroid status influences cholesterol metabolism.