Dosing & Uses
Dosage Forms & Strengths
injectable solution
- 10mcg/mL
tablet
- 5mcg
- 25mcg
- 50mcg
Hypothyroidism
Initial: 25 mcg PO qDay; may increase by 25 mcg q1-2Weeks; not to exceed 100 mcg/day
Maintenance: 25-75 mcg PO qDay
May use 10-12.5 mcg T3 in combo with T4 (decrease T4 dose by 50 mcg)
Nontoxic Goiter
Initial: 5 mcg PO qDay; may increase by 5-10 mcg q1-2Weeks (5 mcg in elderly)
When reach 25 mcg PO qDay, may increase by 12.5 mcg or 25 mcg q1-2Weeks
Maintenance: 75 mcg PO qDay
Myxedema
Initial: 5 mcg PO qDay; may increase by 5-10 mcg/day q1-2Weeks
When reach 25 mcg PO qDay, may increase by 5-25 mcg q1-2Weeks
Maintenance: 50-100 mcg PO qDay
Myxedema Coma
Initial: 25-50 mcg IV
Patients with CVD: 10-20 mcg IV
Doses of at least 65 mcg/day IV associated with lower mortality
Allow 4-12 hr between doses; not to exceed 12 hours
Orphan Designations
Brain metastases: Orphan designation (plus methimazole) for brain metastases in patients with primary lung cancer
Glioblastoma multiforme: Orphan designation (plus methimazole) for treatment of glioblastoma multiforme
Sponsor
- Musli Thyropeutics Ltd; 6 Hagefen Street, P. O. Box 529; Zur Moshe, Israel
Dosage Forms & Strengths
injectable solution
- 10mcg/mL
tablet
- 5mcg
- 25mcg
- 50mcg
Congenital Hypothyroidism
Initial: 5 mcg PO qDay; may increase by 5 mcg q3-4Days
Maintenance
- <1 year: 20 mcg PO qDay
- 1-3 years: 50 mcg PO qDay
- >3 years: 25-75 mcg PO qDay
Nontoxic Goiter
Initial: 5 mcg PO qDay; may increase by 5-10 mcg q1-2Weeks
When reach 25 mcg PO qDay, may increase by 12.5 mcg or 25 mcg q1-2Weeks
Maintenance: 75 mcg PO qDay
5 mcg/day PO; may increase by 5 mcg/day q2Weeks
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (1)
- sodium iodide I-131
liothyronine will decrease the level or effect of sodium iodide I-131 by Other (see comment). Contraindicated. Use of thyroid products or iodine before and during treatment with sodium iodide I-131 decreases uptake of sodium iodide I-131 by the thyroid gland
Serious - Use Alternative (11)
- antithrombin alfa
liothyronine increases effects of antithrombin alfa by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- antithrombin III
liothyronine increases effects of antithrombin III by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- argatroban
liothyronine increases effects of argatroban by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- bemiparin
liothyronine increases effects of bemiparin by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- bivalirudin
liothyronine increases effects of bivalirudin by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- dalteparin
liothyronine increases effects of dalteparin by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- enoxaparin
liothyronine increases effects of enoxaparin by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- fondaparinux
liothyronine increases effects of fondaparinux by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- heparin
liothyronine increases effects of heparin by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- phenindione
liothyronine increases effects of phenindione by pharmacodynamic synergism. Avoid or Use Alternate Drug.
- protamine
liothyronine increases effects of protamine by pharmacodynamic synergism. Avoid or Use Alternate Drug.
Monitor Closely (32)
- amitriptyline
liothyronine increases effects of amitriptyline by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- amoxapine
liothyronine increases effects of amoxapine by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- carbonyl iron
carbonyl iron decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- cholestyramine
cholestyramine decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- clomipramine
liothyronine increases effects of clomipramine by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- colesevelam
colesevelam will decrease the level or effect of liothyronine by Mechanism: inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Administer thyroid hormones at least 4 hr before colesevelam. Elevated thyroid-stimulating hormone (TSH) in patients receiving thyroid hormone.
- crofelemer
crofelemer increases levels of liothyronine by Other (see comment). Use Caution/Monitor. Comment: Crofelemer has the potential to inhibit transporters MRP2 and OATP1A2 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.
- desipramine
liothyronine increases effects of desipramine by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- didanosine
didanosine will decrease the level or effect of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Applies to didanosine chewable tablets and powder for oral solution; administer 2 hr before or several hours after didanosine oral solution or chewable tablet administration
- digoxin
liothyronine decreases effects of digoxin by unknown mechanism. Use Caution/Monitor.
- doxepin
liothyronine increases effects of doxepin by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- doxepin cream
liothyronine increases effects of doxepin cream by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- eluxadoline
eluxadoline increases levels of liothyronine by decreasing metabolism. Use Caution/Monitor. Eluxadoline may increase the systemic exposure of coadministered OATP1B1 substrates.
- ferric maltol
ferric maltol decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- ferrous fumarate
ferrous fumarate decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- ferrous gluconate
ferrous gluconate decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- ferrous sulfate
ferrous sulfate decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- imipramine
liothyronine increases effects of imipramine by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- insulin degludec
liothyronine decreases effects of insulin degludec by pharmacodynamic antagonism. Use Caution/Monitor. Thyroid hormones regulate carbohydrate metabolism, gluconeogenesis, and glycogen stores mobilization; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.
- insulin degludec/insulin aspart
liothyronine decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Use Caution/Monitor. Thyroid hormones regulate carbohydrate metabolism, gluconeogenesis, and glycogen stores mobilization; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.
- insulin inhaled
liothyronine decreases effects of insulin inhaled by pharmacodynamic antagonism. Use Caution/Monitor. Thyroid hormones regulate carbohydrate metabolism, gluconeogenesis, and glycogen stores mobilization; dose of antidiabetic agents may need adjustment and increased frequency of glucose monitoring may be required.
- iron dextran complex
iron dextran complex decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- iron sucrose
iron sucrose decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- lanthanum carbonate
lanthanum carbonate decreases levels of liothyronine by cation binding in GI tract. Use Caution/Monitor. Administer oral thyroid products at least 2 hr before or after lanthanum. Interaction applies only to oral thyroid products only. .
- levonorgestrel oral/ethinylestradiol/ferrous bisglycinate
levonorgestrel oral/ethinylestradiol/ferrous bisglycinate will decrease the level or effect of liothyronine by unknown mechanism. Modify Therapy/Monitor Closely. The estrogen component of combined hormonal contraceptives (CHCs) may raise the serum concentrations of thyroxine-binding globulin. Women on thyroid hormone replacement therapy may need increased doses of thyroid hormone with use of CHCs.
- metformin
liothyronine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.
- nortriptyline
liothyronine increases effects of nortriptyline by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- polysaccharide iron
polysaccharide iron decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- protriptyline
liothyronine increases effects of protriptyline by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- rose hips
rose hips decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- trimipramine
liothyronine increases effects of trimipramine by Other (see comment). Use Caution/Monitor. Comment: Increased catecholamine receptor sensitivity; may increase CNS and cardiovascular effects, including arrhythmias.
- warfarin
liothyronine increases effects of warfarin by unspecified interaction mechanism. Use Caution/Monitor.
Minor (27)
- amobarbital
amobarbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- butabarbital
butabarbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- butalbital
butalbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- carbamazepine
carbamazepine decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- colestipol
colestipol decreases levels of liothyronine by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- dexlansoprazole
dexlansoprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.
- eslicarbazepine acetate
eslicarbazepine acetate decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- esomeprazole
esomeprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.
- ethotoin
ethotoin decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
ethotoin decreases levels of liothyronine by plasma protein binding competition. Minor/Significance Unknown. - fosphenytoin
fosphenytoin decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
fosphenytoin decreases levels of liothyronine by plasma protein binding competition. Minor/Significance Unknown. - furosemide
furosemide increases toxicity of liothyronine by Other (see comment). Minor/Significance Unknown. Comment: High doses (greater than 80 mg) of furosemide may inhibit binding of thyroid hormones to carrier proteins and result in transient increase in free thyroid hormones, followed by overall decrease in total thyroid hormone levels.
- glandular products
glandular products increases effects of liothyronine by pharmacodynamic synergism. Minor/Significance Unknown. Additive effects with thyroid glandular extract.
- guggul
guggul decreases effects of liothyronine by pharmacodynamic antagonism. Minor/Significance Unknown.
- lansoprazole
lansoprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.
- omeprazole
omeprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.
- oxcarbazepine
oxcarbazepine decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- pantoprazole
pantoprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.
- pentobarbital
pentobarbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- phenobarbital
phenobarbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- phenytoin
phenytoin decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
phenytoin decreases levels of liothyronine by plasma protein binding competition. Minor/Significance Unknown. - piracetam
piracetam, liothyronine. Mechanism: unknown. Minor/Significance Unknown. Combination of piracetam and T3+T4 produced confusion, sleep disorder in single case.
- primidone
primidone decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- rabeprazole
rabeprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.
- rifampin
rifampin decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- secobarbital
secobarbital decreases levels of liothyronine by increasing metabolism. Minor/Significance Unknown.
- shepherd's purse
shepherd's purse decreases effects of liothyronine by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.
- theophylline
liothyronine decreases levels of theophylline by increasing elimination. Minor/Significance Unknown.
Adverse Effects
1-10%
Tachycardia (3%)
Hypotension (2%)
Myocardial infarction (2%)
Cardiopulmonary arrest (2%)
<1%
Congestive heart failure
Hypertension
Twitching
Phlebitis
Angina
Fever
Warnings
Black Box Warnings
Thyroid hormones, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss
In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction; larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines, such as those used for their anorectic effects.
Contraindications
Hypersensitivity to thyroid hormone
Acute MI uncomplicated by hypothyroidism, thyrotoxicosis, untreated adrenal insufficiency
Treatment of obesity or infertility
Cautions
Caution in angina, cardiovascular disease, hypopituitarism, DM
May use judiciously in acute MI caused/complicated by hypothyroidism
Perform periodic assessment of thyroid status when using as thyroid replacement
Myxedematous patients are very sensitive to thyroid hormone; start at very low dose
Pregnancy & Lactation
Pregnancy category: A
Lactation: Excreted into breast milk; use caution
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
A synthetic form of natural T3 hormone with same actions as natural product; thyroid hormone raises basal metabolic rate, increases utilization and mobilization of glycogen store, and promotes gluconeogenesis
Absorption
95% absorption
Onset: 2-4 hr
Duration: Several days (hypothyroidism)
Peak plasma time: PO: 1-2 hr
Max response: 2-3 days
Distribution
Protein bound: 99.7%, but not firmly
Metabolism
Hepatic, to deiodinated and conjugated metabolites
Elimination
Half-life: 2.5 days
Excretion: Urine, feces
Administration
IV Administration
Administer q4hr; no more than 12 hr apart
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| liothyronine intravenous - | 10 mcg/mL vial |  | |
| Cytomel oral - | 50 mcg tablet |  | |
| Cytomel oral - | 5 mcg tablet |  | |
| Cytomel oral - | 25 mcg tablet |  | |
| liothyronine oral - | 5 mcg tablet |  | |
| liothyronine oral - | 50 mcg tablet |  | |
| liothyronine oral - | 5 mcg tablet |  | |
| liothyronine oral - | 50 mcg tablet |  | |
| liothyronine oral - | 25 mcg tablet |  | |
| liothyronine oral - | 50 mcg tablet |  | |
| liothyronine oral - | 25 mcg tablet |  | |
| liothyronine oral - | 5 mcg tablet |  | |
| liothyronine oral - | 50 mcg tablet | | |
| liothyronine oral - | 25 mcg tablet | | |
| liothyronine oral - | 5 mcg tablet | |
Copyright © 2010 First DataBank, Inc.
Patient Handout
liothyronine intravenous
NO MONOGRAPH AVAILABLE AT THIS TIME
USES: Consult your pharmacist.
HOW TO USE: Consult your pharmacist.
SIDE EFFECTS: Consult your pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Consult your pharmacist.
DRUG INTERACTIONS: Consult your pharmacist.Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: No monograph available at this time.
MISSED DOSE: Consult your pharmacist.
STORAGE: Consult your pharmacist.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised July 2016. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
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