-5%
Leroid contains synthetic Levothyroxine (T4), chemically identical to the natural thyroid hormone produced by the thyroid gland.
- Conversion: ~30% of T4 is converted to the active form Triiodothyronine (T3) in peripheral tissues.
- Binding: Most T4 is bound to Thyroxine Binding Globulin (TBG), prolonging half-life (6–7 days).
- Shortened half-life in hyperthyroidism (3–4 days)
- Prolonged half-life in hypothyroidism (9–10 days)
- Metabolism: Mainly in the liver via glucuronidation and sulfation; excreted in urine with enterohepatic recirculation.
- Therapeutic benefit: Once-daily dosing maintains stable T3 levels after dosage optimization.
Replacement therapy in hypothyroidism of any cause (primary, secondary, tertiary), except transient hypothyroidism during recovery from subacute thyroiditis.
TSH suppression in:
- Benign goitres and thyroid nodules
- Post-surgical or post-radiotherapy management of thyroid cancer
- Prevention of goitre from goitrogenic drugs (e.g., Lithium).
- Diagnostic aid in thyroid suppression tests.
(Use only under the supervision of a registered physician)