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Liothyronine and Levothyroxine
Liothyronine (T3) and levothyroxine (T4) are thyroid hormones that bind to thyroid hormone receptors to increase metabolic rate and regulate cellular energy production.
Liothyronine (T3) and levothyroxine (T4) are thyroid hormones that bind to thyroid hormone receptors to increase metabolic rate and regulate cellular energy production. Used for Hypothyroidism (replacement therapy), Thyroid cancer (suppressive therapy).
At a glance
| Generic name | Liothyronine and Levothyroxine |
|---|---|
| Also known as | T3 and T4 |
| Sponsor | National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) |
| Drug class | Thyroid hormone replacement |
| Target | Thyroid hormone receptor alpha and beta (TRα, TRβ) |
| Modality | Small molecule |
| Therapeutic area | Endocrinology |
| Phase | FDA-approved |
Mechanism of action
Levothyroxine is converted peripherally to the more active liothyronine (T3), which enters cells and binds to thyroid hormone receptors in the nucleus, modulating gene expression related to metabolism, thermogenesis, and cardiovascular function. This combination therapy aims to provide both the long-acting effects of T4 and the more immediate effects of T3 to optimize thyroid hormone replacement.
Approved indications
- Hypothyroidism
- Thyroid hormone replacement in patients with thyroid cancer requiring TSH suppression
Common side effects
- Tachycardia
- Tremor
- Anxiety
- Insomnia
- Heat intolerance
- Palpitations
Key clinical trials
- Novel Approaches to the Treatment of Hypothyroidism (PHASE2, PHASE3)
- T4/T3 Therapy in Hypothyroidism (PHASE2)
- Precision Medicine Approach for Early Dementia & Mild Cognitive Impairment (PHASE3)
- Thyroid Hormone Replacement After Radio Iodine: Value and Efficacy
- 131I-Omburtamab, in Recurrent Medulloblastoma and Ependymoma (PHASE2)
- Liothyronine in Combination With BIT Regimen for Medulloblastoma With or Without Minimal Residual Disease (PHASE1, PHASE2)
- Desiccated Thyroid Extract Combined With Levothyroxine for TSH Suppression Therapy in DTC (PHASE3)
- Treatment of ARDS With Instilled T3 (PHASE2)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
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