Levothyroxine Sodium 20 ug/mL Injection, Solution
Other active recalls for Levothyroxine Sodium (different manufacturers) — 6 · tap to view
🆔 Identity & classification
Where does this data come from?
🏷️ RxNorm drug class
This medicine belongs to the l-Thyroxine class.
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🏭 Manufacturer & labeler
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🩺 Clinical
- 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?
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Levothyroxine Sodium — tap one for details:
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Ask a licensed pharmacist directly — free, answered by our team.
🧪 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.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
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UNII QTT17582CB
A strong acid used to adjust and maintain the proper pH level in liquid medicines, ensuring stability and preventing breakdown of active ingredients.
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UNII 451W47IQ8X
Sodium chloride is common table salt. It's used in medicines as a buffer to maintain proper pH, as a filler to add bulk, or to adjust the osmotic balance in liquid formulations.
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UNII 55X04QC32I
A strong alkaline chemical used to adjust and maintain the pH balance of liquid medicines. It helps keep the medicine stable and ensures it stays effective during storage.
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UNII F5WR8N145C
Sodium iodide is an inorganic salt containing iodine. In medications, it acts as a source of iodine and may serve as a preservative or stabilizer to help maintain product quality and shelf life.
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UNII 023C2WHX2V
Tromethamine is a chemical buffer that helps maintain the proper acidity level in liquid medicines. It neutralizes acids and stabilizes the solution so the medication remains effective and safe throughout its shelf life.
5 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
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 mL | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | $7.64 | $38.20 / 5 ml |
| Medicare drug plans payPart D · quarterly | No Part D plan price is available for this NDC in our data. | |
| Medicare Part B allowsASP · J0651 | $6.836 / J0651 unit | — |
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🧾 Billing & reimbursement
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Levothyroxine Sodium 20 ug/mLthis 63323-0885-14 | Fresenius | 1 vial | — | — | FDA listed | — |
Where does this data come from?
⏳ 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.
🛈 What do these terms mean?
- 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 9782376 ↗ | Drug product | — | Dec 1, 2036 |
| US 9782376 ↗ | Drug product | — | Dec 1, 2036 |
| US 11135190 ↗ | Drug product | — | Dec 1, 2036 |
| US 10398669 ↗ | Drug product | — | Dec 1, 2036 |
| US 11135190 ↗ | Drug product | — | Dec 1, 2036 |
| US 12636270 ↗ | Drug product | — | Dec 1, 2036 |
| US 11135190 ↗ | Drug product | — | Dec 1, 2036 |
| US 10398669 ↗ | Drug product | — | Dec 1, 2036 |
| US 12636270 ↗ | Drug product | — | Dec 1, 2036 |
| US 9782376 ↗ | Drug product | — | Dec 1, 2036 |
| US 10398669 ↗ | Drug product | — | Dec 1, 2036 |
| US 12636270 ↗ | Drug product | — | Dec 1, 2036 |
Is there a generic version of LEVOTHYROXINE 100 MCG/5 ML VL?
The FDA approved a generic — why can’t I get it at my pharmacy yet?
Why do different websites show different generic release dates?
What does “FDA listed” mean?
What does a patent or protection date mean here?
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Can a generic come out before the last patent expires?
Can a generic come out after the listed dates?
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Where does this data come from?
🗺️ Medicaid utilization & spend
💊 Medicaid utilization by pack size
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
🔬 Reported adverse events (FAERS)
Top reported reactions
Age at onset
Reporter sex
Serious outcomes
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📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 63323-0885-14 You're viewing this | 1 VIAL, SINGLE-DOSE in 1 CARTON (63323-885-14) / 5 mL in 1 VIAL, SINGLE-DOSE | 2018-05-29 | Active |
| 63323-0885-10 | 1 VIAL, SINGLE-DOSE in 1 CARTON (63323-885-10) / 5 mL in 1 VIAL, SINGLE-DOSE | 2018-05-29 | Active |
| 63323-0885-12 | 1 VIAL, SINGLE-DOSE in 1 CARTON (63323-885-12) / 5 mL in 1 VIAL, SINGLE-DOSE | 2018-05-29 | Active |
This pack shows little to no recent Medicaid volume — a different pack size carries most fills. See all packs ↓
Pack size FAQ
What quantity is in NDC 63323-0885-14?
What NDC number is used to bill for this package of Levothyroxine Sodium 20 ug/mL Injection, Solution?
🧭 About this NDC listing & data coverage
What data is (and isn’t) available for this NDC — tap to expand
| 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 | ✓ Available |
| Medicaid utilization (CMS SDUD) | ✓ Available |
Questions about this listing
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📄 Full prescribing information FDA SPL
🚨 Boxed Warning ▾
WARNING: NOT FOR TREATMENT OF OBESITY OR FOR WEIGHT LOSS Thyroid hormones, including Levothyroxine Sodium Injection, should not be used for the treatment of obesity or for weight loss. Larger doses may produce serious or even life threatening manifestations of toxicity. ( 6 , 10 ) WARNING: NOT FOR TREATMENT OF OBESITY OR FOR WEIGHT LOSS Thyroid hormones, including Levothyroxine Sodium Injection, should not be used for the treatment of obesity or for weight loss.
Larger doses may produce serious or even life threatening manifestations of toxicity. ( 6 , 10 )
🎯 Indications and Usage ▾
1 INDICATIONS AND USAGE Levothyroxine Sodium Injection is indicated for the treatment of myxedema coma. Levothyroxine Sodium Injection is L-thyroxine (T4) indicated in adult patients for the treatment of myxedema coma. ( 1 ) Limitations of Use: Not recommended as a substitute for oral levothyroxine sodium because the relative bioavailability of Levothyroxine Sodium Injection to oral levothyroxine sodium has not been established and there is a risk of inaccurate dose conversion.
( 1 ) Limitations of Use: Not recommended as a substitute for oral levothyroxine sodium because the relative bioavailability of Levothyroxine Sodium Injection to oral levothyroxine sodium has not been established and there is a risk of inaccurate dose conversion.
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION Consider the age, general physical condition, cardiac risk factors, and clinical severity of myxedema and duration of myxedema symptoms when determining dosages of Levothyroxine Sodium Injection. ( 2.1 ) Start with lower doses in elderly patients and in patients with underlying cardiovascular disease. ( 2.1 ) The recommended loading dose is 300 mcg to 500 mcg administered intravenously.
( 2.1 ) The recommended maintenance dose is 50 mcg to 100 mcg administered intravenously daily until the patient can tolerate oral therapy. ( 2.1 ) Administer Levothyroxine Sodium Injection intravenously at a rate not to exceed 100 mcg per minute. ( 2.2 ) Do not add Levothyroxine Sodium Injection to intravenous fluids.
( 2.2 )
2.1Dosage Consider the age, general physical condition, cardiac risk factors, and clinical severity of myxedema and duration of myxedema symptoms when determining the starting and maintenance dosages of Levothyroxine Sodium Injection. Start with lower doses in elderly patients and in patients with underlying cardiovascular disease [see Warnings and Precautions ( 5.1 ) and Use in Specific Populations ( 8.5 )]. The recommended loading dose of Levothyroxine Sodium Injection is 300 mcg to 500 mcg administered intravenously.
The recommended maintenance dose of Levothyroxine Sodium Injection is 50 mcg to 100 mcg administered intravenously daily until the patient can tolerate oral therapy.
2.2Administration Instructions Administer Levothyroxine Sodium Injection as an intravenous injection at a rate not to exceed 100 mcg per minute. Do not add Levothyroxine Sodium Injection to intravenous fluids. Inspect Levothyroxine Sodium Injection visually prior to injection. It should appear clear and colorless, solution free of visible particulates. Do not use if particulate matter or coloration is seen. Discard any unused portion.
💊 Dosage Forms and Strengths ▾
3 DOSAGE FORMS AND STRENGTHS Levothyroxine Sodium Injection is clear, colorless solution supplied as: 100 mcg per 5 mL (20 mcg per mL) single-dose vial Injection: 100 mcg per 5 mL (20 mcg per mL) single-dose vial ( 3 )
⛔ Contraindications ▾
4 CONTRAINDICATIONS Uncorrected adrenal insufficiency [see Warnings and Precautions ( 5.2 )] Uncorrected adrenal insufficiency. ( 4 )
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS Cardiac Adverse Reactions in the Elderly and in Patients with Underlying Cardiovascular Disease: Overtreatment may cause arrhythmias, tachycardia, myocardial ischemia and infarction, or worsening of congestive heart failure and death, particularly in patients with cardiovascular disease and in elderly patients. Start with lower doses in elderly patients and in patients with underlying cardiovascular disease and monitor patients after administration ( 5.1 ). Acute Adrenal Crisis in Patients with Concomitant Adrenal Insufficiency: Initiation of thyroid hormone therapy prior to initiating glucocorticoid therapy may precipitate an acute adrenal crisis in patients with adrenal insufficiency.
Treat patients with adrenal insufficiency with replacement glucocorticoids prior to initiating treatment ( 5.2 ). Worsening of Diabetic Control: May worsen glycemic control and result in increased antidiabetic agent or insulin requirements. Carefully monitor glycemic control ( 5.3 ).
5.1Cardiac Adverse Reactions in the Elderly and in Patients with Underlying Cardiovascular Disease Overtreatment with Levothyroxine Sodium Injection may cause arrhythmias, tachycardia, myocardial ischemia and infarction, or worsening of congestive heart failure and death, particularly in patients with cardiovascular disease and in elderly patients. Start with lower doses in elderly patients and in patients with underlying cardiovascular disease and monitor patients after administration of Levothyroxine Sodium Injection for cardiac adverse reactions.
5.2Acute Adrenal Crisis in Patients with Concomitant Adrenal Insufficiency Chronic autoimmune thyroiditis, which can lead to myxedema coma, may occur in association with other autoimmune disorders such as adrenal insufficiency. Thyroid hormone increases metabolic clearance of glucocorticoids. Initiation of thyroid hormone therapy prior to initiating glucocorticoid therapy may precipitate an acute adrenal crisis in patients with adrenal insufficiency [see Contraindications ( 4 )].
Treat patients with adrenal insufficiency with replacement glucocorticoids prior to initiating treatment with Levothyroxine Sodium Injection.
5.3Worsening 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 [see Drug Interactions ( 7.2 )].
🤒 Adverse Reactions ▾
6 ADVERSE REACTIONS Adverse reactions associated with levothyroxine are primarily those of hyperthyroidism due to therapeutic overdosage [see Warnings and Precautions ( 5 ) , 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: diarrhea, vomiting, abdominal cramps, elevations in liver function tests Dermatologic: flushing, rash Seizures have been reported rarely with the institution of levothyroxine therapy.
Adverse reactions associated with Levothyroxine Sodium Injection are primarily those of hyperthyroidism due to therapeutic overdosage: fatigue, increased appetite, weight loss, heat intolerance, fever, excessive sweating, headache, hyperactivity, nervousness, anxiety, irritability, emotional lability, insomnia, tremors, muscle weakness, muscle spasm, palpitations, tachycardia, arrhythmias, increased pulse and blood pressure, heart failure, angina, myocardial infarction, cardiac arrest, dyspnea, diarrhea, vomiting, abdominal cramps, elevations in liver function tests, flushing, and rash.
( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Kabi USA, LLC at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 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 gastrointestinal 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., synthesis, secretion, catabolism, protein binding, and target tissue response) that may alter the therapeutic response to Levothyroxine Sodium Injection. ( 7 )
7.1Drugs Known to Affect Thyroid Hormone Pharmacokinetics Many drugs affect thyroid hormone pharmacokinetics and metabolism (e.g., synthesis, secretion, catabolism, protein binding, and target tissue response) and may alter the therapeutic response to Levothyroxine Sodium Injection (see Tables 1 - 3 ). Table 1: Drugs That May Alter T 4 and Triiodothyronine (T 3 ) Serum Transport Without Effecting Free Thyroxine (FT 4 ) 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 levothyroxine results in an initial transient increase in FT 4 . Continued administration results in a decrease in serum T 4 and normal FT 4 and TSH concentrations.
Salicylates (> 2 g/day) Salicylates inhibit binding of T 4 and T 3 to TBG and transthyretin. An initial increase in serum FT 4 is followed by return of FT 4 to normal levels with sustained therapeutic serum salicylate concentrations, although total T 4 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 increase 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 2: Drugs That May Alter Hepatic Metabolism of T 4 (Hypothyroidism) Potential impact: Stimulation of hepatic microsomal drug-metabolizing enzyme activity may cause increased hepatic degradation of levothyroxine, resulting in increased levothyroxine 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 (UGT) and leads to a lower T4 serum levels. Changes in thyroid status may occur if barbiturates are added or withdrawn from patients being treated for hypothyroidism. Rifampin has been shown to accelerate the metabolism of levothyroxine.
Table 3: Drugs That May Decrease Conversion of T 4 to T 3 Potential impact: Administration of these enzyme inhibitors decreases the peripheral conversion of T 4 to T 3 , leading to decreased T 3 levels. However, serum T 4 levels are usually normal but may occasionally be slightly increased. Drug or Drug Class Effect Beta-adrenergic antagonists (e.g., Propranolol > 160 mg/day) In patients treated with large doses of propranolol (> 160 mg/day), T 3 and T 4 levels change slightly, TSH levels remain normal, and patients are clinically euthyroid.
It should be noted that actions of particular beta-adrenergic antagonists may be impaired when the hypothyroid patient is converted to the euthyroid state. Glucocorticoids (e.g., Dexamethasone ≥ 4 mg/day) Short-term administration of large doses of glucocorticoids may decrease serum T 3 concentrations by 30% with minimal change in serum T 4 levels. However, long-term glucocorticoid therapy may result in s…
🔄 Drug / Laboratory Test Interactions ▾
7.8Drug-Laboratory Test Interactions Consider changes in TBG concentration when interpreting T4 and T3 values. Measure and evaluate unbound (free) hormone and/or determine the free T4 index (FT4I) in this circumstance. Pregnancy, infectious hepatitis, estrogens, estrogen containing oral contraceptives, and acute intermittent porphyria increase TBG concentrations.
Nephrosis, severe hypoproteinemia, severe liver disease, acromegaly, androgens, and corticosteroids decrease TBG concentration. Familial hyper- or hypo-thyroxine binding globulinemias have been described, with the incidence of TBG deficiency approximating 1 in 9,000.
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS
8.1Pregnancy Risk Summary There is no available data with use of Levothyroxine Sodium Injection in pregnant women. The clinical data in pregnant women treated with oral levothyroxine to maintain a euthyroid state have not reported increased rates of major birth defects, miscarriages, or adverse maternal or fetal outcomes (see Data ). There are risks to the mother and fetus associated with myxedema coma in pregnancy (see Clinical Considerations ) .
Animal reproduction studies have not been conducted with levothyroxine sodium. 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 Myxedema coma is a medical emergency which can be fatal, if left untreated. Delaying treatment in pregnant women with myxedema coma increases the risk of maternal and fetal morbidity and mortality. Life-sustaining therapy for the pregnant woman should not be withheld due to potential concerns regarding the effects of Levothyroxine Sodium Injection on the fetus.
Data Human Data There is no available data with use of Levothyroxine Sodium Injection in pregnant women. Oral levothyroxine is approved for use as a replacement therapy in hypothyroidism. There is a long experience of oral levothyroxine use in pregnant women that has 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 Published studies report that levothyroxine is present in human milk following the administration of oral levothyroxine. 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. There is no available data with use of Levothyroxine Sodium Injection in lactating women.
The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for levothyroxine and any potential adverse effects on the breastfed infant from levothyroxine or from the underlying maternal condition.
8.4Pediatric Use The safety and efficacy of Levothyroxine Sodium Injection have not been established in pediatric patients.
8.5Geriatric Use Because of the increased prevalence of cardiovascular disease among the elderly, initiate Levothyroxine Sodium Injection with lower doses in elderly patients and in patients with underlying cardiovascular disease and closely monitor for cardiac adverse reactions. Atrial arrhythmias can occur in elderly patients. Atrial fibrillation is the most common of the arrhythmias observed with levothyroxine overtreatment in the elderly [see Dosage and Administration ( 2.1 ) and Warnings and Precautions ( 5.1 )].
🤰 Pregnancy ▾
8.1Pregnancy Risk Summary There is no available data with use of Levothyroxine Sodium Injection in pregnant women. The clinical data in pregnant women treated with oral levothyroxine to maintain a euthyroid state have not reported increased rates of major birth defects, miscarriages, or adverse maternal or fetal outcomes (see Data ). There are risks to the mother and fetus associated with myxedema coma in pregnancy (see Clinical Considerations ) .
Animal reproduction studies have not been conducted with levothyroxine sodium. 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 Myxedema coma is a medical emergency which can be fatal, if left untreated. Delaying treatment in pregnant women with myxedema coma increases the risk of maternal and fetal morbidity and mortality. Life-sustaining therapy for the pregnant woman should not be withheld due to potential concerns regarding the effects of Levothyroxine Sodium Injection on the fetus.
Data Human Data There is no available data with use of Levothyroxine Sodium Injection in pregnant women. Oral levothyroxine is approved for use as a replacement therapy in hypothyroidism. There is a long experience of oral levothyroxine use in pregnant women that has 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 The safety and efficacy of Levothyroxine Sodium Injection have not been established in pediatric patients.
🧓 Geriatric Use ▾
8.5Geriatric Use Because of the increased prevalence of cardiovascular disease among the elderly, initiate Levothyroxine Sodium Injection with lower doses in elderly patients and in patients with underlying cardiovascular disease and closely monitor for cardiac adverse reactions. Atrial arrhythmias can occur in elderly patients. Atrial fibrillation is the most common of the arrhythmias observed with levothyroxine overtreatment in the elderly [see Dosage and Administration ( 2.1 ) and Warnings and Precautions ( 5.1 )].
🆘 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.
Reduce the Levothyroxine Sodium Injection dose or temporarily discontinue if signs or symptoms of overdosage occur. Initiate appropriate supportive treatment as dictated by the patient's medical status.
🧬 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 levothyroxine (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 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 Distribution Circulating thyroid hormones are greater than 99% bound to plasma proteins, including thyroxine binding globulin (TBG), thyroxine binding prealbumin (TBPA), and 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 )].
Metabolism T4 is slowly eliminated. The major pathway of thyroid hormone metabolism is through sequential deiodination. Approximately eighty percent 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, where it is hydrolyzed and eliminated in feces as the free hormones.
Urinary excretion of T4 decreases with age. Table 1: Pharmacokinetic Parameters of Thyroid Hormones in Euthyroid Patients T 4 : Levothyroxine T 3 : Liothyronine 1 3 to 4 days in hyperthyroidism, 9 to 10 days in hypothyroidism. 2 Includes TBG, TBPA, and TBA.
Hormone Ratio in Thyroglobulin Biologic Potency Half-Life (Days) Protein Binding (%) 2 T 4 10 to 20 1 6 to 8 1
99.96T 3 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 levothyroxine (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 Levothyroxine Sodium Injection is a clear, colorless solution available as follows: NDC Total Strength per Total Volume Concentration 63323-885-14 100 mcg per 5 mL 20 mcg per mL Protect from light in the original vial in a carton and store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. The unopened vial may be stored for up to 24 hours exposed to indoor lighting outside of the carton. The drug product is preservative free.
Discard any unused portion. Novaplus is a registered trademark of Vizient, Inc. Manufactured by: Fresenius Kabi Lake Zurich, IL 60047 www.fresenius-kabi.com/us 451680 Fresenius Logo
📋 Description ▾
11 DESCRIPTION Levothyroxine Sodium Injection contains synthetic crystalline levothyroxine (T4) in sodium salt form. Levothyroxine sodium has an empirical formula of C 15 H 10 I 4 NNaO 4 , a molecular weight of 798.85 g/mol (anhydrous), and the following structural formula: Levothyroxine Sodium Injection is a sterile, preservative free, clear, colorless, sterile solution for intravenous administration available as: 100 mcg per 5 mL (20 mcg per mL). Each mL of Levothyroxine Sodium Injection also contains 10 mg Tromethamine, USP; 0.14 mg Sodium Iodide, USP; 6.48 mg Sodium Chloride, USP; and Water for Injection, USP Sodium hydroxide, NF and/or Hydrochloric acid, USP may have been added for pH adjustment (9.5 – 10.8).
Levothyroxine Sodium Injection is in single dose clear glass vials. Structural Formula