Liothyronine — uses, dosing, side effects & the brands that sell it · pharmaranks
Liothyronine: uses, dosing, side effects & brands
Liothyronine is a l-triiodothyronine sold in the U.S. under 3 brand and generic names, for goiter, myxedema and thyroid neoplasms. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
By the pharmaranks editorial team·Reviewed against the FDA (openFDA label, NDC Directory & Enforcement) sources·How we research
Key facts
Drug class
L-Triiodothyronine
Treats
Goiter, Myxedema and Thyroid Neoplasms
Available as
Tablet · Injectable
Sold as
3 products — Cytomel, Liothyronine Sodium and Triostat
From the FDA label for Cytomel (application NDA010379). Other liothyronine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Administer CYTOMEL orally once daily and individual dosage according to patient response and laboratory findings ( 2.1 ) • See full prescribing information for recommended dosage for hypothyroidism ( 2.2 ) TSH suppression in well-differentiated thyroid cancer ( 2.3 ) and for thyroid suppression test ( 2.4 ) • When switching a patient to CYTOMEL, discontinue levothyroxine therapy and initiate CYTOMEL at a low dosage. Gradually increase the dose according to the patient's response ( 2.5 ) • Adequacy of therapy determined with periodic monitoring of TSH and T3 levels as well as clinical status ( 2.6 ) 2.1 General Principles of Dosing The dose of CYTOMEL for hypothyroidism or pituitary TSH suppression depends on a variety of factors including: the patient's age, body weight, cardiovascular status, concomitant medical conditions (including pregnancy), concomitant medications, co-administered food and the specific nature of the condition being treated [see Dosage and Administration (2.2 , 2.3 , 2.4) , Warnings and Precautions (5) , and Drug Interactions (7) ] . Dosing must be individualized to account for these factors and dose adjustments made based on periodic assessment of the patient's clinical response and laboratory parameters [see Dosage and Administration (2.4) ] . Administer CYTOMEL tablets orally once daily. 2.2 Recommended Dosage for…
Liothyronine side effects
associated with CYTOMEL therapy are primarily those of hyperthyroidism due to therapeutic overdosage [see Warnings and Precautions (5.4) and Overdosage (10) ] . They include the following: General : fatigue, increased appetite, weight loss, heat intolerance, fever, excessive sweating Central nervous system : headache, hyperactivity, nervousness, anxiety, irritability, emotional lability, insomnia Musculoskeletal : tremors, muscle weakness and cramps Cardiovascular : palpitations, tachycardia, arrhythmias, increased pulse and blood pressure, heart failure, angina, myocardial infarction, cardiac arrest Respiratory : dyspnea Gastrointestinal : diarrhea, vomiting, abdominal cramps, elevations in liver function tests Dermatologic : hair loss, flushing Endocrine : decreased bone mineral density Reproductive : menstrual irregularities, impaired fertility Most common adverse reactions for CYTOMEL are primarily those of hyperthyroidism due to therapeutic overdosage: arrhythmias, myocardial infarction, dyspnea, headache, nervousness, irritability, insomnia, tremors, muscle weakness, increased appetite, weight loss, diarrhea, heat intolerance, menstrual irregularities, and skin rash ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer, Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . Adverse Reactions in Pediatric Patients Pseudotumor…
Every liothyronine product we track (3)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Liothyronine pill imprints
Imprint
Strength
Colour
Shape
Maker
KPI;115
5 ug
white
round
—
KPI;116
25 ug
white
round
—
KPI;117
50 ug
white
round
—
18
5 ug
white
round
—
KPI;115
5 ug
white
round
—
KPI;116
25 ug
white
Frequently asked questions
What is liothyronine?
CYTOMEL tablets contain the active ingredient, liothyronine (L-triiodothyronine or LT 3 ), a synthetic form of a thyroid hormone liothyronine in sodium salt form. It is chemically designated as L-Tyrosine, O -(4-hydroxy-3-iodophenyl)-3,5-diiodo-, monosodium salt. The molecular formula, molecular weight and structural formula of liothyronine sodium are given below. CYTOMEL tablets contain liothyronine sodium equivalent to liothyronine in 5 mcg, 25 mcg, and 50 mcg. Inactive ingredients consist of calcium sulfate, corn starch, gelatin, stearic acid, sucrose and talc. Chemical Structure
What kind of drug is liothyronine?
The FDA classifies liothyronine as a l-triiodothyronine. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take liothyronine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run liothyronine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is liothyronine sold under?
We track 3 liothyronine-containing products in the U.S.: Cytomel, Liothyronine Sodium and Triostat. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does liothyronine come in?
Across the brands we track, liothyronine is currently marketed as tablet and injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic liothyronine?
Yes. Our catalog lists 1 generic liothyronine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Who shouldn’t take liothyronine
CYTOMEL is contraindicated in patients with uncorrected adrenal insufficiency [see Warnings and Precautions (5.3) ] . Uncorrected adrenal cortical insufficiency ( 4 )
Liothyronine drug interactions
See full prescribing information for drugs that affect thyroid hormone pharmacokinetics and metabolism (e.g., absorption, synthesis, secretion, catabolism, protein binding, and target tissue response) and may alter the therapeutic response to CYTOMEL ( 7 ) 7.1 Drugs Known to Affect Thyroid Hormone Pharmacokinetics Many drugs can exert effects on thyroid hormone pharmacokinetics (e.g. absorption, synthesis, secretion, catabolism, protein binding, and target tissue response) and may alter the therapeutic response to CYTOMEL (see Tables 1 – 4). Table 1: Drugs That May Decrease T3 Absorption (Hypothyroidism) Potential impact: Concurrent use may reduce the efficacy of CYTOMEL by binding and delaying or preventing absorption, potentially resulting in hypothyroidism. Drug or Drug Class Effect Bile Acid Sequestrants -Colesevelam -Cholestyramine -Colestipol Ion Exchange Resins -Kayexalate -Sevelamer Bile acid sequestrants and ion exchange resins are known to decrease thyroid hormones absorption. Administer CYTOMEL at least 4 hours prior to these drugs or monitor TSH levels. Table 2: Drugs That May Alter Triiodothyronine (T3) Serum Transport Without Affecting Free Thyroxine (FT4) Concentration (Euthyroidism) Drug or Drug Class Effect Clofibrate Estrogen-containing oral contraceptives Estrogens (oral) Heroin / Methadone 5-Fluorouracil Mitotane Tamoxifen These drugs may increase serum…