Tirosint levothyroxine sodium 75 ug Capsule, 10-count
Other active recalls for Levothyroxine Sodium (different manufacturers) — 6 · tap to view
🆔 Identity & classification
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🏷️ RxNorm drug class
This medicine belongs to the l-Thyroxine class.
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🏭 Manufacturer & labeler
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🩺 Clinical
Levothyroxine is used to treat hypothyroidism (condition where the thyroid gland does not produce enough thyroid hormone). It is also used with surgery and radioactive iodine therapy to treat thyroid cancer. Levothyroxine is in a class of medications called hormones. It works by replacing thyroid hormone that is normally produced by the body. Without thyroid hormone, your body cannot function properly, which may result in poor growth, slow speech, lack of energy, excessive tiredness, constipation, weight gain, hair loss, dry, thick skin, increased sensitivity to cold, joint and muscle pain, he...
Read the full MedlinePlus article ↗- Your thyroid gland isn't making enough of a hormone called T4, which your whole body depends on to regulate your energy, metabolism, heart rate, and more. Levothyroxine is a precis...
- What exactly is levothyroxine doing for me — why do I need to take it every day?
- Timing really does make a difference with this medication. Food — especially high-fiber foods or anything soy-based — can block your gut from absorbing it properly. Taking it 30 to...
- Why does it matter so much when I take it — can't I just take it with breakfast?
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🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
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UNII 2G86QN327L
Gelatin is a protein derived from animal collagen, commonly used in medicines as a gelling agent and capsule material. It helps create soft or hard capsule shells that hold and release medication, and can also thicken liquid formulations.
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UNII PDC6A3C0OX
Glycerin is a clear, thick liquid derived from plant oils or fats. It acts as a humectant to retain moisture, a sweetener, and a solvent in medications.
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UNII 059QF0KO0R
Water is a liquid solvent that dissolves and mixes ingredients together in liquid medicines, syrups, and injections. It helps distribute the active drug evenly throughout the product.
3 inactive ingredients listed in the exact product block matched to this NDC.
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ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
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💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per each | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $4.92 | $49.22 / 10 capsules |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Levothyroxine Sodium 75 ug 82347-0020-04 | YARAL | 30 capsules | $3.893 | — | FDA listed | — |
| Tirosint 75 ugthis 71858-0020-01 | IBSA | 10 capsules | — | — | Discontinued | — |
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⏳ Availability & generic status
The FDA lists approved generic versions of this medicine, but that does not always mean a pharmacy can get one today. Patent rules, launch agreements, supply and pricing can affect when generics actually arrive.
Why the date isn’t exact: Generic timing can change because patents may be challenged, settled, licensed, added, removed, or worked around with a narrower label — and FDA approval does not always mean a pharmacy can get the generic today.
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- Patent
- Legal protection listed in the Orange Book that may delay generic approval or launch. Issued by the U.S. Patent & Trademark Office.
- Substance patent
- Covers the active drug molecule itself — the hardest to design around. A generic generally can’t launch until it expires.
- Formulation (product) patent
- Covers a specific formulation or dosage form. A generic can sometimes work around it with a different formulation.
- Method-of-use patent
- A patent covering one specific approved use of the drug — not necessarily the whole molecule. A generic can sometimes launch with a “skinny label” that carves out the protected use and keeps the others.
- Skinny label
- A generic label that omits a still-patented use when the FDA allows it — letting a generic reach the market for the unprotected uses.
- Exclusivity
- FDA-granted marketing protection, separate from patents — e.g. 5-yr new chemical entity, 7-yr orphan drug, or a +6-month pediatric extension.
- Paragraph IV
- A generic applicant’s formal challenge to a listed patent. It can potentially lead to earlier generic entry, but often involves litigation or a settlement.
- RLD / RS
- Reference Listed Drug — the brand product the FDA uses as the reference for generic applications. Reference Standard — the product the FDA expects generics to compare against in bioequivalence testing.
- TE / AB rating
- FDA therapeutic-equivalence rating. An AB rating generally means the FDA considers a generic therapeutically equivalent to — and substitutable for — the brand.
- LOE (loss of exclusivity)
- The latest patent or exclusivity currently listed — the loss-of-exclusivity / latest-listed-protection date shown on this page. Paragraph-IV challenges and settlements can move the real date earlier; FDA approval and a manufacturer’s decision to market can move it later.
Built from the FDA Orange Book. The bars above are scaled to each protection’s expiry; the red LOE marker is the last one to lapse.
| Patent | Type | Use code | Expires |
|---|---|---|---|
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
| US 12564565 ↗ | Drug product | — | Sep 26, 2044 |
Is there a generic version of TIROSINT 75 MCG CAPSULE?
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📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
🔬 Reported adverse events (FAERS)
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📦 Packaging — all sizes for this product
| Package NDC | Description | Per unit | Per pack | Marketing start | Status |
|---|---|---|---|---|---|
| 71858-0020-01 You're viewing this | 1 BLISTER PACK in 1 CARTON (71858-0020-1) / 10 CAPSULE in 1 BLISTER PACK | — | — | 2018-12-01 | Discontinued by firm |
| 71858-0020-04 | 3 BLISTER PACK in 1 CARTON (71858-0020-4) / 10 CAPSULE in 1 BLISTER PACK | $4.38 / ea | $131.55 | 2018-12-01 | Active |
| 71858-0020-02 | 3 BLISTER PACK in 1 CARTON (71858-0020-2) / 10 CAPSULE in 1 BLISTER PACK | — | — | 2025-08-24 | Active |
Pack size FAQ
What quantity is in NDC 71858-0020-01?
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What NDC number is used to bill for this package of Tirosint levothyroxine sodium 75 ug Capsule?
Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.
🧭 About this NDC listing & data coverage
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| NDC identity (package / product / labeler codes) | ✓ Available |
| Labeler | ✓ Available |
| Product & package description | ✓ Available |
| Marketing category & status | ✓ Available |
| Active ingredient / dosage form / route | ✓ Available |
| FDA label (SPL via DailyMed) | ✓ Available |
| Package photos | ✓ Available |
| Inactive ingredients (structured) | ✓ Available |
| NADAC pharmacy acquisition price (CMS) | — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey. |
| Orange Book / therapeutic-equivalence data | ✓ Available |
| HCPCS J-code billing crosswalk | — Not published for this NDC Most self-administered / retail products have no J-code — that is normal. |
| Medicaid utilization (CMS SDUD) | — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold. |
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📄 Full prescribing information FDA SPL
🚨 Boxed Warning ▾
WARNING: NOT FOR TREATMENT OF OBESITY or FOR WEIGHT LOSS Thyroid hormones, including TIROSINT, 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 [see Adverse Reactions (6) , Drug Interactions (7.7) , and Overdosage (10) ].
WARNING: NOT FOR TREATMENT OF OBESITY or FOR WEIGHT LOSS See full prescribing information for complete boxed warning Thyroid hormones, including TIROSINT, should not be used for the treatment of obesity or for weight loss. Doses beyond the range of daily hormonal requirements may produce serious or even life threatening manifestations of toxicity ( 6 , 10 ).
🎯 Indications and Usage ▾
1 INDICATION AND USAGE TIROSINT is L-thyroxine (T4) indicated for adults and pediatric patients 6 years and older with: Hypothyroidism - As replacement therapy in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism ( 1 ) Pituitary Thyrotropin (Thyroid-Stimulating Hormone, TSH) Suppression - As an adjunct to surgery and radioiodine therapy in the management of thyrotropin-dependent well-differentiated thyroid cancer ( 1 ) Limitations of Use: Not indicated for suppression of benign thyroid nodules and nontoxic diffuse goiter in iodine-sufficient patients ( 1 ) Not indicated for treatment of transient hypothyroidism during the recovery phase of subacute thyroiditis ( 1 ) Hypothyroidism TIROSINT is indicated as a replacement therapy in adults and pediatric patients 6 years and older with primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism.
Pituitary Thyrotropin (Thyroid-Stimulating Hormone, TSH) Suppression TIROSINT is indicated as an adjunct to surgery and radioiodine therapy in the management of adults and pediatric patients 6 years and older with thyrotropin-dependent well-differentiated thyroid cancer. Limitations of Use: TIROSINT is not indicated for suppression of benign thyroid nodules and nontoxic diffuse goiter in iodine-sufficient patients as there are no clinical benefits and overtreatment with TIROSINT may induce hyperthyroidism [see Warnings and Precautions (5.4) ].
TIROSINT is not indicated for treatment of transient hypothyroidism during the recovery phase of subacute thyroiditis.
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION Administer once daily, on an empty stomach, one-half to one hour before breakfast ( 2.1 ) Administer at least 4 hours before or after drugs that are known to interfere with absorption ( 2.1 ) Evaluate the need for dose adjustments when regularly administering within an hour of certain foods that may affect TIROSINT absorption ( 2.1 ) Swallow TIROSINT capsules whole, do not cut, crush, or chew ( 2.1 ) Starting dose depends on a variety of factors, including age, body weight, cardiovascular status, concomitant medical conditions (including pregnancy), concomitant medications, co-administered food, and the specific nature of the condition being treated.
Peak therapeutic effect may not be attained for 4-6 weeks ( 2.2 ) See full prescribing information for dosing in specific patient populations ( 2.3 ) Adequacy of therapy determined with periodic monitoring of TSH and/or T4 as well as clinical status ( 2.4 )
2.1General Administration Information Administer TIROSINT as a single daily oral dose, on an empty stomach, one-half to one hour before breakfast. Administer TIROSINT at least 4 hours before or after drugs known to interfere with TIROSINT absorption [see Drug Interactions (7.1) ] Evaluate the need for dose adjustments when regularly administering within an hour of certain foods that may affect TIROSINT absorption [see Drug Interactions (7.9) and Clinical Pharmacology (12.3) ]. Swallow TIROSINT capsules whole, do not cut, crush, or chew.
2.2General Principles of Dosing The dose of TIROSINT 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 (2.3) , 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) ].
The peak therapeutic effect of a given dose of TIROSINT may not be attained for 4 to 6 weeks.
2.3Dosing In Specific Patient Populations Primary Hypothyroidism in Adults and in Adolescents in Whom Growth and Puberty are Complete Start TIROSINT at the full replacement dose in otherwise healthy, non-elderly individuals who have been hypothyroid for only a short time (such as a few months).The average full replacement dose of TIROSINT is approximately 1.6 mcg per kg per day (for example: 100-125 mcg per day for a 70 kg adult). Adjust the dose by 12.5 to 25 mcg increments every 4 to 6 weeks until the patient is clinically euthyroid and the serum TSH returns to normal.
Doses greater than 200 mcg per day are seldom required. An inadequate response to daily doses greater than 300 mcg per day is rare and may indicate poor compliance, malabsorption, drug interactions, or a combination of these factors. For elderly patients or patients with underlying cardiovascular disease, start with a dose of 12.5 to 25 mcg per day.
Increase the dose every 6 to 8 weeks, as needed, until the patient is clinically euthyroid and the serum TSH returns to normal. The full replacement dose of TIROSINT may be less than 1 mcg per kg per day in elderly patients. In patients with severe longstanding hypothyroidism, start with a dose of 12.5 to 25 mcg per day.
Adjust the dose in 12.5 to 25 mcg increments every 2 to 4 weeks until the patient is clinically euthyroid and the serum TSH level is normalized. Secondary or Tertiary Hypothyroidism Start TIROSINT at the full replacement dose in otherwise healthy, non-elderly individuals. Start with a lower dose in elderly patients with underlying cardiovascular disease or patients with severe longstanding hypothyroidism as described above.
Serum TSH is not a reliable measure of TIROSINT dose adequacy in…
💊 Dosage Forms and Strengths ▾
3 DOSAGE FORMS AND STRENGTHS TIROSINT capsules are amber-colored, round/biconvex capsules, imprinted with a dosage strength specific letter on one side and containing a viscous amber-colored liquid and are available as follows: Strength (mcg) Imprint Code 13 A 25 E
37.5 O 44 R 50 G
62.5L 75 H 88 J 100 K 112 M 125 N 137 P 150 S 175 U 200 Y Capsules: 13, 25, 37.5, 44, 50, 62.5, 75, 88, 100, 112, 125, 137, 150, 175, 200 mcg ( 3 )
⛔ Contraindications ▾
4 CONTRAINDICATIONS TIROSINT is contraindicated in patients with uncorrected adrenal insufficiency [see Warnings and Precautions (5.3) ]. Uncorrected adrenal insufficiency ( 4 )
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS Cardiac adverse reactions in the elderly and in patients with underlying cardiovascular disease: Initiate TIROSINT at less than the full replacement dose because of the increased risk of cardiac adverse reactions, including atrial fibrillation. ( 2.3 , 5.1 , 8.5 ) Myxedema coma: Do not use oral thyroid hormone drug products to treat myxedema coma. ( 5.2 ) Acute adrenal crisis in patients with concomitant adrenal insufficiency: Treat with replacement glucocorticoids prior to initiation of TIROSINT treatment.
( 5.3 ) Prevention of hyperthyroidism or incomplete treatment of hypothyroidism: Proper dose titration and careful monitoring is critical to prevent the persistence of hypothyroidism or the development of hyperthyroidism. ( 5.4 ) Worsening of diabetic control: Therapy in patients with diabetes mellitus may worsen glycemic control and result in increased antidiabetic agent or insulin requirements. Carefully monitor glycemic control after starting, changing, or discontinuing thyroid hormone therapy.
( 5.5 ) Decreased bone mineral density associated with thyroid hormone over-replacement: Over-replacement can increase bone resorption and decrease bone mineral density. Give the lowest effective dose. ( 5.6 )
5.1Cardiac Adverse Reactions in the Elderly and in Patients with Underlying Cardiovascular Disease Overtreatment with levothyroxine may cause an increase in heart rate, cardiac wall thickness, and cardiac contractility and may precipitate angina or arrhythmias, particularly in patients with cardiovascular disease and in elderly patients. Initiate TIROSINT therapy in this population at lower doses than those recommended in younger individuals or in patients without cardiac disease [see Dosage and Administration (2.3) and Use in Specific Populations (8.5) ].
Monitor for cardiac arrhythmias during surgical procedures in patients with coronary artery disease receiving suppressive TIROSINT therapy. Monitor patients receiving concomitant TIROSINT and sympathomimetic agents for signs and symptoms of coronary insufficiency . If cardiac symptoms develop or worsen, reduce the TIROSINT dose or withhold it for one week and restart at a lower dose.
5.2Myxedema Coma Myxedema coma is a life-threatening emergency characterized by poor circulation and hypometabolism, and may result in unpredictable absorption of levothyroxine sodium from the gastrointestinal tract. Use of oral thyroid hormone drug products is not recommended to treat myxedema coma. Administer thyroid hormone products formulated for intravenous administration to treat myxedema coma.
5.3Acute Adrenal Crisis in Patients with Concomitant Adrenal Insufficiency Thyroid hormone increases metabolic clearance of glucocorticoids. Initiation of thyroid hormone therapy prior to initiating glucocorticoid therapy precipitate an acute adrenal crisis in patient with adrenal insufficiency. Treat patients with adrenal insufficiency with replacement glucocorticoids prior to initiating treatment with TIROSINT [see Contraindications (4) ].
5.4Prevention of Hyperthyroidism or Incomplete Treatment of Hypothyroidism TIROSINT has a narrow therapeutic index. Over- or under-treatment with TIROSINT may have negative effects on growth and development, cardiovascular function, bone metabolism, reproductive function, cognitive function, emotional state, gastrointestinal function, and on glucose and lipid metabolism. Titrate the dose of TIROSINT carefully and monitor response to titration to avoid these effects [see Dosage and Administration (2.4) ] .
Monitor for the presence of drug or food interactions when using TIROSINT and adjust the dose as necessary [see Drug Interactions (7) and Clinical Pharmacology (12.3) ].
5.5Worsening of Diabetic Control Addition of levothyroxine therapy in patients with diabetes mellitus may worsen glycemic control and result in increased antidiabetic agent or insulin requirements. Carefully monitor glycemic control after starting, changing, or…
🤒 Adverse Reactions ▾
6 ADVERSE REACTIONS Adverse reactions associated with TIROSINT therapy are primarily those of hyperthyroidism due to therapeutic overdosage [see Warnings and Precautions (5) 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, muscle spasm Cardiovascular: palpitations, tachycardia, arrhythmias, increased pulse and blood pressure, heart failure, angina, myocardial infarction, cardiac arrest Respiratory : dyspnea Gastrointestinal (GI): diarrhea, vomiting, abdominal cramps, elevations in liver function tests Dermatologic: hair loss, flushing, rash Endocrine: decreased bone mineral density Reproductive: menstrual irregularities, impaired fertility Seizures have been reported rarely with the institution of levothyroxine therapy.
Adverse reactions associated with TIROSINT are primarily those of hyperthyroidism due to therapeutic overdosage including: arrhythmias, myocardial infarction, dyspnea, muscle spasm, 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 IBSA Pharma Inc. at 1-800-587-3513, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . Adverse Reactions in Children Pseudotumor cerebri and slipped capital femoral epiphysis have been reported in children receiving levothyroxine therapy.
Overtreatment may result in craniosynostosis in infants and premature closure of the epiphyses in children with resultant compromised adult height. Hypersensitivity Reactions Hypersensitivity reactions to inactive ingredients have occurred in patients treated with thyroid hormone products. These include urticaria, pruritus, skin rash, flushing, angioedema, various GI symptoms (abdominal pain, nausea, vomiting and diarrhea), fever, arthralgia, serum sickness and wheezing.
Hypersensitivity to levothyroxine itself is not known to occur.
🔄 Drug Interactions ▾
7 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 TIROSINT ( 7 )
7.1Drugs Known to Affect Thyroid Hormone Pharmacokinetics Many drugs can exert effects thyroid hormone pharmacokinetics (e.g., absorption, synthesis, secretion, catabolism, protein binding, and target tissue response) and may alter the therapeutic response to TIROSINT (see Tables 2 to 5 below). Table 2: Drugs That May Decrease T4 Absorption (Hypothyroidism) Potential impact: Concurrent use may reduce the efficacy of TIROSINT by binding and delaying or preventing absorption, potentially resulting in hypothyroidism Drug or Drug Class Effect Calcium Carbonate Ferrous Sulfate Calcium carbonate may form an insoluble chelate with levothyroxine, and ferrous sulfate likely forms a ferric-thyroxine complex.
Administer TIROSINT at least 4 hours apart from these agents. Orlistat Monitor patients treated concomitantly with orlistat and TIROSINT for changes in thyroid function. Bile Acid Sequestrants -Colesevelam -Cholestyramine -Colestipol Ion Exchange Resins -Kayexalate -Sevelamer Bile acid sequestrants and ion exchange resins are known to decrease levothyroxine absorption.
Administer TIROSINT at least 4 hours prior to these drugs or monitor thyrotropin (TSH) levels. Other drugs: Proton Pump Inhibitors Sucralfate Antacids - Aluminum & Magnesium Hydroxides - Simethicone Gastric acidity is an essential requirement for adequate absorption of levothyroxine. Sucralfate, antacids and proton pump inhibitors may cause hypochlorhydria, affect intragastric pH, and reduce levothyroxine absorption.
Monitor patients appropriately Table 3: Drugs That May Alter T4 and 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 thyroxine-binding globulin (TBG) concentration. Androgens / Anabolic Steroids Asparaginase Glucocorticoids Slow-Release Nicotinic Acid These drugs may decrease serum TBG concentration.
Potential impact (below) : Administration of these agents with TIROSINT results in an initial transient increase in FT4. Continued administration results in a decrease in serum T4 and normal FT4 and TSH concentrations. Salicylates (> 2 g/day) Salicylates inhibit binding of T4 and T3 to TBG and transthyretin.
An initial increase in serum FT4 is followed by return of FT4 to normal levels with sustained therapeutic serum salicylate concentrations, although total T4 levels may decrease by as much as 30%. Other drugs: Carbamazepine Furosemide (> 80 mg IV) Heparin Hydantoins Non-Steroidal Anti-inflammatory Drugs - Fenamates These drugs may cause protein-binding site displacement . Furosemide has been shown to inhibit the protein binding of T4 to TBG and albumin, causing an increased free-T4 fraction in serum.
Furosemide competes for T4-binding sites on TBG, prealbumin, and albumin, so that a single high dose can acutely lower the total T4 level. Phenytoin and carbamazepine reduce serum protein binding of levothyroxine, and total and free-T4 may be reduced by 20% to 40%, but most patients have normal serum TSH levels and are clinically euthyroid. Closely monitor thyroid hormone parameters.
Table 4: Drugs That May Alter Hepatic Metabolism of T4 (Hypothyroidism) Potential impact: Stimulation of hepatic microsomal drug-metabolizing enzyme activity may cause increased hepatic degradation of levothyroxine, resulting in increased TIROSINT requirements. Drug or Drug Class Effect Phenobarbital Rifampin Phenobarbital has been shown to reduce the response to thyroxine. Phenobarbital increases L-thyroxine metabolism by inducing uridine 5'-diphospho-glucuronosyltransferase…
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS Pregnancy may require the use of higher doses of TIROSINT ( 2.3 , 8.1 )
8.1Pregnancy Risk Summary Experience with levothyroxine use in pregnant women, including data from post-marketing studies, have not reported increased rates of major birth defects or miscarriages [see Data ]. There are risks to the mother and fetus associated with untreated hypothyroidism in pregnancy. Since thyroid-stimulating hormone (TSH) levels may increase during pregnancy, TSH should be monitored and TIROSINT dosage adjusted during pregnancy [see Clinical Considerations ] .
There are no animal studies conducted with levothyroxine during pregnancy. TIROSINT should not be discontinued during pregnancy and hypothyroidism diagnosed during pregnancy should be promptly treated. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Maternal hypothyroidism during pregnancy is associated with a higher rate of complications, including spontaneous abortion, gestational hypertension, pre-eclampsia, stillbirth, and premature delivery. Untreated maternal hypothyroidism may have an adverse effect on fetal neurocognitive development.
Dose Adjustments During Pregnancy and the Postpartum Period Pregnancy may increase TIROSINT requirements. Serum TSH level should be monitored and the TIROSINT dosage adjusted during pregnancy. Since postpartum TSH levels are similar to preconception values, the TIROSINT dosage should return to the pre-pregnancy dose immediately after delivery [see Dosage and Administration (2.3) ].
Data Human Data Levothyroxine is approved for use as a replacement therapy for hypothyroidism. There is a long experience of levothyroxine use in pregnant women, including data from post-marketing studies that have not reported increased rates of fetal malformations, miscarriages or other adverse maternal or fetal outcomes associated with levothyroxine use in pregnant women.
8.2Lactation Risk Summary Limited published studies report that levothyroxine is present in human milk. However, there is insufficient information to determine the effects of levothyroxine on the breastfed infant and no available information on the effects of levothyroxine on milk production. Adequate levothyroxine treatment during lactation may normalize milk production in hypothyroid lactating mothers.
The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for TIROSINT and any potential adverse effects on the breastfed infant from TIROSINT or from the underlying maternal condition.
8.4Pediatric Use TIROSINT is indicated for use in pediatric patients 6 years and older. The initial dose of TIROSINT varies with age and body weight. Dosing adjustments are based on an assessment of the individual patient's clinical and laboratory parameters [see Dosage and Administration (2.3 , 2.4) ] In children in whom a diagnosis of permanent hypothyroidism has not been established, discontinue TIROSINT administration for a trial period.
Obtain serum T4 and TSH levels at the end of the trial period, and use laboratory test results and clinical assessments to guide diagnosis and treatment, if warranted. Congenital Hypothyroidism [see Dosage and Administration (2.3 , 2.4) ] Rapid restoration of normal serum T4 concentrations is essential for preventing the adverse effects of congenital hypothyroidism on intellectual development as well as on overall physical growth and maturation. Therefore, initiate levothyroxine therapy immediately upon diagnosis.
Levothyroxine is generally continued for life in these patients. Closely monitor children during the first two weeks of TIROSINT therapy for cardiac overload and arr…
🤰 Pregnancy ▾
8.1Pregnancy Risk Summary Experience with levothyroxine use in pregnant women, including data from post-marketing studies, have not reported increased rates of major birth defects or miscarriages [see Data ]. There are risks to the mother and fetus associated with untreated hypothyroidism in pregnancy. Since thyroid-stimulating hormone (TSH) levels may increase during pregnancy, TSH should be monitored and TIROSINT dosage adjusted during pregnancy [see Clinical Considerations ] .
There are no animal studies conducted with levothyroxine during pregnancy. TIROSINT should not be discontinued during pregnancy and hypothyroidism diagnosed during pregnancy should be promptly treated. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Maternal hypothyroidism during pregnancy is associated with a higher rate of complications, including spontaneous abortion, gestational hypertension, pre-eclampsia, stillbirth, and premature delivery. Untreated maternal hypothyroidism may have an adverse effect on fetal neurocognitive development.
Dose Adjustments During Pregnancy and the Postpartum Period Pregnancy may increase TIROSINT requirements. Serum TSH level should be monitored and the TIROSINT dosage adjusted during pregnancy. Since postpartum TSH levels are similar to preconception values, the TIROSINT dosage should return to the pre-pregnancy dose immediately after delivery [see Dosage and Administration (2.3) ].
Data Human Data Levothyroxine is approved for use as a replacement therapy for hypothyroidism. There is a long experience of levothyroxine use in pregnant women, including data from post-marketing studies that have not reported increased rates of fetal malformations, miscarriages or other adverse maternal or fetal outcomes associated with levothyroxine use in pregnant women.
🧒 Pediatric Use ▾
8.4Pediatric Use TIROSINT is indicated for use in pediatric patients 6 years and older. The initial dose of TIROSINT varies with age and body weight. Dosing adjustments are based on an assessment of the individual patient's clinical and laboratory parameters [see Dosage and Administration (2.3 , 2.4) ] In children in whom a diagnosis of permanent hypothyroidism has not been established, discontinue TIROSINT administration for a trial period.
Obtain serum T4 and TSH levels at the end of the trial period, and use laboratory test results and clinical assessments to guide diagnosis and treatment, if warranted. Congenital Hypothyroidism [see Dosage and Administration (2.3 , 2.4) ] Rapid restoration of normal serum T4 concentrations is essential for preventing the adverse effects of congenital hypothyroidism on intellectual development as well as on overall physical growth and maturation. Therefore, initiate levothyroxine therapy immediately upon diagnosis.
Levothyroxine is generally continued for life in these patients. Closely monitor children during the first two weeks of TIROSINT therapy for cardiac overload and arrhythmias. Closely monitor patients to avoid undertreatment and overtreatment.
Undertreatment may have deleterious effects on intellectual development and linear growth. Overtreatment may adversely affect the tempo of brain maturation and accelerate the bone age with resultant premature closure of the epiphyses and compromised adult stature. Acquired Hypothyroidism in Pediatric Patients Closely monitor patients to avoid undertreatment and overtreatment.
Undertreatment may result in poor school performance due to impaired concentration and slowed mentation and in reduced adult height. Overtreatment may accelerate the bone age and result in premature epiphyseal closure and compromised adult stature. Treated children may manifest a period of catch-up growth, which may be adequate in some cases to normalize adult height.
In children with severe or prolonged hypothyroidism, catch-up growth may not be adequate to normalize adult height.
🧓 Geriatric Use ▾
8.5Geriatric Use Because of the increased prevalence of cardiovascular disease among the elderly, initiate TIROSINT therapy at less than the full replacement dose [ see Warnings and Precautions (5.1) and Dosage and Administration (2.3) ]. Atrial arrhythmias can occur in elderly patients. Atrial fibrillation is the most common of the arrhythmias observed with levothyroxine overtreatment in the elderly .
🆘 Overdosage ▾
10 OVERDOSAGE The signs and symptoms of overdosage are those of hyperthyroidism [see Warnings and Precautions (5) and Adverse Reactions (6) ]. In addition, confusion and disorientation may occur. Cerebral embolism, shock, coma, and death have been reported.
Seizures occurred in a 3-year-old child ingesting 3.6 mg of levothyroxine. Symptoms may not necessarily be evident or may not appear until several days after ingestion of levothyroxine sodium. Reduce the TIROSINT dose or discontinue temporarily if signs or symptoms of overdosage occur.
Initiate appropriate supportive treatment as dictated by the patient's medical status. For current information on the management of poisoning or overdosage, contact the National Poison Control Center at 1-800-222-1222 or www.poison.org.
🧬 Clinical Pharmacology ▾
12 CLINICAL PHARMACOLOGY
12.1Mechanism of Action Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis. Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA. This hormone nuclear receptor complex activates gene transcription and synthesis of messenger RNA and cytoplasmic proteins.
The physiological actions of thyroid hormones are produced predominantly by T3, the majority of which (approximately 80%) is derived from T4 by deiodination in peripheral tissues.
12.2Pharmacodynamics Oral levothyroxine sodium is a synthetic T4 hormone that exerts the same physiologic effect as endogenous T4, thereby maintaining normal T4 levels when a deficiency is present.
12.3Pharmacokinetics Absorption Absorption of orally administered T 4 from the gastrointestinal (GI) tract ranges from 40% to 80%. The majority of the levothyroxine dose is absorbed from the jejunum and upper ileum. T4 absorption is increased by fasting, and decreased in malabsorption syndromes and by certain foods such as soybeans.
Dietary fiber decreases the bioavailability of T4. Absorption may also decrease with age. In addition, many drugs and foods affect T4 absorption. [see Drug Interactions (7) ] Distribution Circulating thyroid hormones are greater than 99% bound to plasma proteins, including thyroxine-binding globulin (TBG), thyroxine-binding prealbumin (TBPA), and thyroxine-binding albumin (TBA), whose capacities and affinities vary for each hormone.
The higher affinity of both TBG and TBPA for T4 partially explains the higher serum levels, slower metabolic clearance, and longer half-life of T4 compared to T3. Protein-bound thyroid hormones exist in reverse equilibrium with small amounts of free hormone. Only unbound hormone is metabolically active.
Many drugs and physiologic conditions affect the binding of thyroid hormones to serum proteins [see Drug Interactions (7) ]. Thyroid hormones do not readily cross the placental barrier [see Use in Specific Populations (8.1) ]. Elimination Metabolism T4 is slowly eliminated (see Table 6 ) .
The major pathway of thyroid hormone metabolism is through sequential deiodination. Approximately 80% of circulating T3 is derived from peripheral T4 by monodeiodination. The liver is the major site of degradation for both T4 and T3, with T4 deiodination also occurring at a number of additional sites, including the kidney and other tissues.
Approximately 80% of the daily dose of T4 is deiodinated to yield equal amounts of T3 and reverse T3 (rT3). T3 and rT3 are further deiodinated to diiodothyronine. Thyroid hormones are also metabolized via conjugation with glucuronides and sulfates and excreted directly into the bile and gut where they undergo enterohepatic recirculation.
Excretion Thyroid hormones are primarily eliminated by the kidneys. A portion of the conjugated hormone reaches the colon unchanged and is eliminated in the feces. Approximately 20% of T4 is eliminated in the stool.
Urinary excretion of T4 decreases with age. Table 6: Pharmacokinetic Parameters of Thyroid Hormones in Euthyroid Patients Hormone Ratio in Thyroglobulin Biologic Potency Half-Life (Days) Protein Binding (%) Includes TBG, TBPA and TBA. Levothyroxine (T4) 10 – 20 1 6 – 7 3 – 4 days in hyperthyroidism, 9 – 10 days in hypothyroidism.
99.96Liothyronine (T3) 1 4 ≤ 2 99.5
🧬 Mechanism of Action ▾
12.1Mechanism of Action Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis. Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA. This hormone nuclear receptor complex activates gene transcription and synthesis of messenger RNA and cytoplasmic proteins.
The physiological actions of thyroid hormones are produced predominantly by T3, the majority of which (approximately 80%) is derived from T4 by deiodination in peripheral tissues.
📦 How Supplied / Storage and Handling ▾
16 HOW SUPPLIED/STORAGE AND HANDLING
16.1How Supplied TIROSINT (levothyroxine sodium) capsules are amber-colored, round/biconvex capsules, imprinted with a dosage strength specific letter on one side and containing a viscous amber-colored liquid. They are supplied as follows: Table 7: TIROSINT Packaging Description - Boxes of 30 capsules, consisting of 3 blisters with 10 capsules each Strength (mcg) Color Shown on box and blister packing, not on individual capsules. Imprint Code NDC 13 Green A 71858-0005-4 25 Orange E 71858-0010-4
37.5 Dark Blue O 71858-0012-4 44 Red R 71858-0013-4 50 White G 71858-0015-4
62.5Grey L 71858-0017-4 75 Purple H 71858-0020-4 88 Olive J 71858-0025-4 100 Yellow K 71858-0030-4 112 Rose M 71858-0035-4 125 Brown N 71858-0040-4 137 Turquoise P 71858-0045-4 150 Blue S 71858-0050-4 175 Lilac U 71858-0055-4 200 Pink Y 71858-0060-4 The dosage strength on each box is clearly identified in several locations, and is associated with a distinct color. The color of the circles on the blister is the same color as on the box. Each blister pack contains 10 capsules placed in individual cavities labeled with the dosage strength and the product name (TIROSINT).
16.2Storage and Handling Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°-30°C (59-86°F) [see USP Controlled Room Temperature]. TIROSINT capsules should be protected from heat, light and moisture. Do not separate the individual cavities containing the drug from the intact blister as important information may be lost (i.e., manufacturer/distributor names, distributor contact phone number, lot number, and expiration date), and do not remove the individual capsules from blister packaging until ready to use.
📦 Storage and Handling ▾
16.2Storage and Handling Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°-30°C (59-86°F) [see USP Controlled Room Temperature]. TIROSINT capsules should be protected from heat, light and moisture. Do not separate the individual cavities containing the drug from the intact blister as important information may be lost (i.e., manufacturer/distributor names, distributor contact phone number, lot number, and expiration date), and do not remove the individual capsules from blister packaging until ready to use.
📋 Description ▾
11 DESCRIPTION TIROSINT (levothyroxine sodium) capsules for oral use contain synthetic L-3,3',5,5'-tetraiodothyronine sodium salt [levothyroxine (T 4 ) sodium]. Synthetic T4 is chemically identical to that produced in the human thyroid gland. Levothyroxine (T4) sodium has an empirical formula of C 15 H 10 I 4 NNaO 4 ∙ x H 2 O (where x = 5), molecular weight of 798.86 g/mol (anhydrous), and structural formula as shown: TIROSINT (levothyroxine sodium) capsules are amber-colored, round/biconvex capsules containing a viscous amber-colored liquid.
The inactive ingredients in TIROSINT are gelatin, glycerin and water. Chemical Structure
💬 Information for Patients ▾
17 PATIENT COUNSELING INFORMATION Advise the patient and/or the caregiver to read the FDA-approved patient labeling (Patient Information Sheet). Dosing and Administration Instruct patients to take TIROSINT only as directed by their healthcare provider. Instruct patients to take TIROSINT one-half to one hour before breakfast.
Inform patients that agents such as iron and calcium supplements and antacids can decrease the absorption of levothyroxine. Instruct patients not to take TIROSINT within 4 hours of these agents. Instruct patients that TIROSINT capsules should be swallowed whole and never be cut, crushed, or chewed.
To assist with identifying the name and strength of each TIROSINT capsule, instruct patients not to remove capsules from the blisters in advance, particularly if they are taking multiple strengths. Instruct patients to notify their healthcare provider should they become pregnant or are thinking of becoming pregnant while taking TIROSINT. Important Information Inform patients that it may take several weeks before they notice an improvement in symptoms.
Inform patients that the levothyroxine in TIROSINT is intended to replace a hormone that is normally produced by the thyroid gland. Generally, replacement therapy is to be taken for life. Inform patients that TIROSINT should not be used as a primary or adjunctive therapy in a weight control program.
Instruct patients to notify their healthcare provider if they are taking any other medications, including prescription and over-the-counter preparations [see Drug Interactions (7) ] . Instruct patients to notify their healthcare provider of any other medical conditions, particularly heart disease, diabetes, clotting disorders, and adrenal or pituitary gland problems, as the dose of medications used to control these other conditions may need to be adjusted while taking TIROSINT. If they have diabetes, instruct patients to monitor their blood and/or urinary glucose levels as directed by their physician and immediately report any changes to their physician.
If patients are taking anticoagulants, their clotting status should be checked frequently. Instruct patients to notify their physician or dentist that they are taking TIROSINT prior to any surgery. Adverse Reactions Instruct patients to notify their healthcare provider if they experience any of the following symptoms: rapid or irregular heartbeat, chest pain, shortness of breath, leg cramps, headache, nervousness, irritability, sleeplessness, tremors, change in appetite, weight loss, vomiting, diarrhea, excessive sweating, heat intolerance, fever, changes in menstrual periods, hives or skin rash, or any other unusual medical event.
Inform patients that partial hair loss may occur rarely during the first few months of TIROSINT therapy, but this is usually temporary.