Liothyronine (L-triiodothyronine)

Liothyronine Brand Names- Cytomel | Triostat

What is Liothyronine

Liothyronine (L-triiodothyronine) is a synthetic sodium salt of the endogenous thyroid hormone triiodothyronine (T3).

The oral tablet is indicated for use as replacement or supplemental therapy in the treatment of hypothyroidism of any etiology, except transient hypothyroidism during the recovery phase of subacute thyroiditis, including congenital hypothyroidism (cretinism).

The replacement of thyroid hormone using levothyroxine (T4) alone is sufficient in most individuals with hypothyroidism and is the preferred replacement therapy for routine use in patients of all ages.

However, in select patients, such as patients who continue to have symptoms despite euthyroid status after stabilization of a dose for T4 replacement, partial substitution of T3 for T4 may be beneficial.

Liothyronine is also used as a diagnostic agent in TSH suppression tests as an aid in detecting hyperthyroidism, and as an adjunct agent in the treatment of well-differentiated thyroid cancer; however, levothyroxine is usually the preferred agent for these purposes.

Liothyronine injection is most commonly used in the treatment of myxedema coma.

Due to the fast onset of action of liothyronine, combination therapy with levothyroxine and liothyronine may be recommended for selected patients in the treatment of myxedema coma, as T4 to T3 conversion is impaired in some patients.

Liothyronine first received FDA-approval for clinical use in 1954.

Indications

  1. cretinism
  2. hyperthyroidism diagnosis
  3. hypothyroidism
  4. myxedema coma
  5. organ preservation
  6. thyroid cancer

Thyroid Products Equivalent Oral Dosages; listings are estimates only:

Preparation-dosage equivalents-(T4: T3 ratio)

Levothyroxine: 100 mcg -(1:0)

Liothyronine: 25 mcg -(0:1)

Levothyroxine; Liothyronine (e.g., Liotrix-1): 50 to 60 mcg/12.5 to 15 mcg -(4:1)

Thyroid USP: 60 mg (1 grain) -(2 to 5:1)

For the treatment of hypothyroidism of any etiology, except during the recovery phase of subacute thyroiditis; used as a replacement in primary (thyroidal), secondary (pituitary), tertiary (hypothalamic), congenital (cretinism), or acquired hypothyroidism

Side Effects

  1. abdominal pain
  2. alopecia
  3. amenorrhea
  4. angina
  5. angioedema
  6. anorexia
  7. anxiety
  8. appetite stimulation
  9. arrhythmia exacerbation
  10. arthralgia
  11. atrial fibrillation
  12. cardiac arrest
  13. craniosynostosis
  14. diarrhea
  15. dyspnea
  16. elevated hepatic enzymes
  17. emotional lability
  18. epiphyseal closure
  19. fatigue
  20. fever
  21. flushing
  22. growth inhibition
  23. headache
  24. heart failure
  25. heat intolerance
  26. hyperactivity
  27. hyperhidrosis
  28. hypertension
  29. hyperthyroidism
  30. hypotension
  31. increased intracranial pressure
  32. infertility
  33. insomnia
  34. irritability
  35. muscle cramps
  36. myocardial infarction
  37. nausea
  38. osteopenia
  39. osteoporosis
  40. palpitations
  41. peripheral edema
  42. phlebitis
  43. pruritus
  44. pseudotumor cerebri
  45. rash
  46. serum sickness
  47. sinus tachycardia
  48. thyrotoxicosis
  49. tremor
  50. urticaria
  51. vomiting
  52. weakness
  53. weight loss
  54. wheezing

Monitoring Parameters

  • blood pressure
  • growth rate
  • heart rate
  • thyroid function tests (TFTs)
  • total T3 (triiodothyronine)
  • weight

Contraindications

  • acute myocardial infarction
  • adrenal insufficiency
  • angina
  • breast-feeding
  • cardiac arrhythmias
  • cardiac disease
  • coronary artery disease
  • diabetes mellitus
  • epiphyseal closure
  • geriatric
  • heart failure
  • hypertension
  • hyperthyroidism
  • hyponatremia
  • hypopituitarism
  • hypothermia
  • infertility
  • intramuscular administration
  • myocardial infarction
  • myxedema
  • obesity treatment
  • osteopenia
  • pregnancy
  • renal failure
  • renal impairment
  • subcutaneous administration
  • surgery
  • thyrotoxicosis
  • water intoxication

Interactions

  • Acarbose
  • Acetaminophen; Butalbital
  • Acetaminophen; Butalbital; Caffeine
  • Acetaminophen; Butalbital; Caffeine; Codeine
  • Acetohexamide
  • Albiglutide
  • Alogliptin
  • Alogliptin; Metformin
  • Alogliptin; Pioglitazone
  • Alpha-glucosidase Inhibitors
  • Aluminum Hydroxide
  • Aluminum Hydroxide; Magnesium Carbonate
  • Aluminum Hydroxide; Magnesium Hydroxide
  • Aluminum Hydroxide; Magnesium Hydroxide; Simethicone
  • Aluminum Hydroxide; Magnesium Trisilicate
  • Amiodarone
  • Amobarbital
  • Amoxapine
  • Amoxicillin; Clarithromycin; Lansoprazole
  • Amoxicillin; Clarithromycin; Omeprazole
  • Asparaginase Erwinia chrysanthemi
  • Aspirin, ASA; Butalbital; Caffeine
  • Aspirin, ASA; Butalbital; Caffeine; Codeine
  • Aspirin, ASA; Omeprazole
  • Atropine; Hyoscyamine; Phenobarbital; Scopolamine
  • Azelastine; Fluticasone
  • Barbiturates
  • Beclomethasone
  • Belladonna Alkaloids; Ergotamine; Phenobarbital
  • Beta-agonists
  • Beta-blockers
  • Betamethasone
  • Budesonide
  • Budesonide; Formoterol
  • Butabarbital
  • Calcium
  • Calcium Acetate
  • Calcium Carbonate
  • Calcium Carbonate; Magnesium Hydroxide
  • Calcium Carbonate; Risedronate
  • Calcium Carbonate; Simethicone
  • Calcium Chloride
  • Calcium Gluconate
  • Calcium; Vitamin D
  • Canagliflozin
  • Canagliflozin; Metformin
  • Carbamazepine
  • Chlorpropamide
  • Cholestyramine
  • Chromium
  • Ciclesonide
  • Cocaine
  • Colesevelam
  • Colestipol
  • Corticosteroids
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  • Dapagliflozin; Metformin
  • Dapagliflozin; Saxagliptin
  • Deflazacort
  • Dexamethasone
  • Dexlansoprazole
  • Didanosine, ddI
  • Digoxin
  • Dulaglutide
  • Empagliflozin
  • Empagliflozin; Linagliptin
  • Empagliflozin; Linagliptin; Metformin
  • Empagliflozin; Metformin
  • enteral feedings
  • Ertugliflozin; Metformin
  • Ertugliflozin; Sitagliptin
  • Esomeprazole
  • Esomeprazole; Naproxen
  • Estrogens
  • Ethinyl Estradiol; Norethindrone Acetate; Ferrous fumarate
  • Ethinyl Estradiol; Norethindrone; Ferrous fumarate
  • Exenatide
  • Fludrocortisone
  • Flunisolide
  • Fluoxymesterone
  • Fluticasone
  • Fluticasone; Salmeterol
  • Fluticasone; Umeclidinium; Vilanterol
  • Fluticasone; Vilanterol
  • food
  • Formoterol; Mometasone
  • Furosemide
  • Glimepiride
  • Glimepiride; Pioglitazone
  • Glimepiride; Rosiglitazone
  • Glipizide
  • Glipizide; Metformin
  • Glyburide
  • Glyburide; Metformin
  • Hetastarch; Dextrose; Electrolytes
  • Hydantoins
  • Hydrocortisone
  • Imatinib
  • Indinavir
  • Insulin Degludec; Liraglutide
  • Insulin Glargine; Lixisenatide
  • Insulins
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  • Iopamidol
  • Iopromide
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  • Iron
  • Iron Salts
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  • Isoniazid, INH; Pyrazinamide, PZA; Rifampin
  • Isoniazid, INH; Rifampin
  • Isosulfan Blue
  • Ketamine
  • L-Asparaginase Escherichia coli
  • Lansoprazole
  • Lansoprazole; Naproxen
  • Lanthanum Carbonate
  • Linagliptin
  • Linagliptin; Metformin
  • Liraglutide
  • Lithium
  • Lixisenatide
  • Magnesium
  • Maprotiline
  • Meglitinides
  • Mephobarbital
  • Metformin
  • Metformin; Pioglitazone
  • Metformin; Repaglinide
  • Metformin; Rosiglitazone
  • Metformin; Saxagliptin
  • Metformin; Sitagliptin
  • Methimazole
  • Methohexital
  • Methylprednisolone
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  • Mometasone
  • Non-Ionic Contrast Media
  • Omeprazole
  • Omeprazole; Amoxicillin; Rifabutin
  • Omeprazole; Sodium Bicarbonate
  • Orlistat
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  • Pioglitazone
  • Polycarbophil
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  • Sevelamer
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  • Simvastatin; Sitagliptin
  • Sitagliptin
  • Sodium Ferric Gluconate Complex; ferric pyrophosphate citrate
  • Sodium Iodide
  • Sodium Polystyrene Sulfonate
  • Somatropin, rh-GH
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  • Sympathomimetics
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  • Tolazamide
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  • Tretinoin, ATRA
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  • Tricyclic antidepressants
  • Warfarin
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