liothyronine (Rx)

Brand and Other Names:Cytomel, Triostat, more...Liothyronine T3, Thyroid Hormone

Dosing & Uses

AdultPediatricGeriatric

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

Next:

Interactions

Interaction Checker

and liothyronine

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            All Interactions Sort By:
             activity indicator 

            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.

            Previous
            Next:

            Adverse Effects

            1-10%

            Tachycardia (3%)

            Hypotension (2%)

            Myocardial infarction (2%)

            Cardiopulmonary arrest (2%)

            <1%

            Congestive heart failure

            Hypertension

            Twitching

            Phlebitis

            Angina

            Fever

            Previous
            Next:

            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

            Previous
            Next:

            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.

            Previous
            Next:

            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

            Previous
            Next:

            Administration

            IV Administration

            Administer q4hr; no more than 12 hr apart

            Previous
            Next:

            Images

            BRAND FORM. UNIT PRICE PILL IMAGE
            liothyronine intravenous
            -
            10 mcg/mL vial
            Cytomel oral
            -
            5 mcg tablet
            Cytomel oral
            -
            50 mcg tablet
            Cytomel oral
            -
            25 mcg tablet
            liothyronine oral
            -
            5 mcg tablet
            liothyronine oral
            -
            50 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
            -
            5 mcg tablet
            liothyronine oral
            -
            50 mcg tablet
            liothyronine oral
            -
            25 mcg tablet
            liothyronine oral
            -
            5 mcg tablet
            liothyronine oral
            -
            5 mcg tablet

            Copyright © 2010 First DataBank, Inc.

            Previous
            Next:

            Patient Handout

            Select a drug:
            Patient Education
            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.

            Previous
            Next:

            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
            Additional Offers
            Email to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Email Forms to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Previous
            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.