HomeNDC LookupIngredientsThyroid, Unspecified › 79739-7372-01
Thyroid 60 mg Tablet, 100-count — NDC 79739-7372-01 package photo

Thyroid 60 mg Tablet, 100-count

by LGM PHARMA SOLUTIONS, LLC · 100 TABLET in 1 BOTTLE (79739-7372-1)
NDC 79739-7372-01
🏷️ FDA NDC (as labeled) 79739-7372-1 billing pads the package segment with a zero
Rx only Discontinued Non-controlled ⚠ Discontinued by firm
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →
⚠️
Excluded from the active FDA NDC Directory. The labeler reported this product as discontinued, so it is excluded from the active NDC Directory. The listing was last certified through Sep 2026. A label may still appear on DailyMed, but the NDC is no longer in the current FDA NDC Directory. Search the FDA NDC Directory ↗

🆔 Identity & classification

FDA NDC (as labeled) 79739-7372-1
Product NDC 79739-7372
11-digit billing NDC 79739737201
UNII 0B4FDL9I6P
SPL Set ID 5bdc43b8-04a1-4767-8489-bf3ee485a00c
DEA schedule Non-controlled
Marketing category UNAPPROVED DRUG OTHER
Marketing status Discontinued
FDA listing status Discontinued by firm (certified through Sep 2026)
Marketing start 2025-01-02
Route ORAL
Dosage form TABLET
Substance THYROID, UNSPECIFIED
Why two NDCs? The FDA registers this code as 79739-7372-1 — a 5-4-1 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the package segment → 79739-7372-01. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏭 Manufacturer & labeler

LabelerLGM PHARMA SOLUTIONS, LLC
Labeler code79739
First marketedJan 2025
Product typeHuman Prescription Drug
Portfolio16 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

📗 Our plain-language guide HelloPharmacist
  • Desiccated thyroid is made from dried pig (porcine) thyroid glands and naturally contains both T4 and T3 — the two main thyroid hormones your body makes. Synthetic options like lev...
  • What exactly is desiccated thyroid, and is it the same as synthetic thyroid hormone?
  • No — and this is really important. If your thyroid is working normally, taking thyroid hormone will not cause meaningful weight loss. Worse, taking it in higher doses to try to los...
  • Can I use thyroid tablets to lose weight?
📖 Read our full Thyroid guide →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

🧪 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.

Loading inactive ingredients from the official FDA label in the background. No external source is being called by this page request.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 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 systemPer eachPer 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 · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
NP Thyroid 60 38 ug/1; 9 ug 42192-0330-01 Acella 100 tablets $0.665 Availability likely
Thyroid 60 mg 62559-0742-01 ANI 100 tablets $0.665 Availability likely
Thyroid 60 mg 69680-0167-00 Vitruvias 100 tablets $0.665 Availability likely
EvexiTHROID 38 ug/1; 9 ug 73352-0696-10 Trifluent 100 tablets $0.665 Availability likely
Niva Thyroid 60 mg 75834-0312-01 Nivagen 100 tablets $0.665 Availability likely
Amerithroid 60 mg 82685-0343-01 Oliva 100 tablets $0.665 Availability likely
Armour Thyroid 60 mg 00456-0459-01 Allergan, 100 tablets $1.127 Availability likely
NP Thyroid 9 ug/1; 38 ug 17224-0503-28 Calvin 28 tablets FDA listed
Armour Thyroid 60 mg 50090-0190-00 A-S 100 tablets FDA listed
NP Thyroid 60 38 ug/1; 9 ug 50090-5216-00 A-S 90 tablets FDA listed
NP Thyroid 60 38 ug/1; 9 ug 51655-0132-52 Northwind 30 tablets FDA listed
RenThyroid 38 ug/1; 9 ug 64950-0172-01 Genus 100 tablets FDA listed
NP Thyroid 60 38 ug/1; 9 ug 68071-3691-03 NuCare 30 tablets FDA listed
NP Thyroid 60 38 ug/1; 9 ug 71335-0414-01 Bryant 60 tablets FDA listed
Np Thyroid 60 9 ug/1; 38 ug 72189-0202-90 DIRECT 90 tablets FDA listed
NP Thyroid 60 38 ug/1; 9 ug 76420-0568-01 Asclemed 100 tablets FDA listed
Thyroid 60 mgthis 79739-7372-01 LGM 100 tablets Discontinued
About this product: other versions of the same ingredient, strength and form are listed above, least expensive first, with FDA equivalence ratings where available.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2025
On the market since
Jan 2025
📍
2026
Currently FDA-listed
1 year listed
🔒
·
No generic listed yet
brand only
ℹ️No FDA-approved generic found

We did not find an FDA-approved generic match for this exact strength, form and route.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

📊 Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Thyroid — the program that covers self-administered drugs. 2 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Thyroid. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$303.8K
Claims incl. refills
7.1K
Beneficiaries
5.1K
Spend / beneficiary
$59.80
Spend / claim
$42.62
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for Thyroid (this brand).

Top reported reactions

Fatigue261
Headache208
Nausea194
Pain193
Diarrhoea177
Dyspnoea151
Dizziness145

Age at onset

Child1
Adult192
Elderly214

Reporter sex

2,828 reports
Male · 15%
Female · 85%
Unknown · 0%

Serious outcomes

Hospitalization499
Reports over time (by year) — tap or hover for the count & year
2022 2023 2024 2026 143 81
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
79739-7372-01 You're viewing this 100 TABLET in 1 BOTTLE (79739-7372-1) 2025-01-02 Discontinued by firm

🧭 About this NDC listing & data coverage

Finished prescription product Marketed without an FDA application No longer marketed (per FDA listing data)

Listed without an FDA application

This product's marketing category indicates it is marketed without an approved FDA application (no NDA, ANDA, or BLA on file). Having an NDC does not by itself establish FDA approval — the NDC Directory is a listing system, not an approval decision. Approval-linked data such as Orange Book therapeutic-equivalence ratings therefore does not apply.

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) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is 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 — Not published for this NDC Applies only to products approved under an NDA/ANDA; many listings are out of scope.
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.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Is this NDC FDA-approved?
An NDC listing does not by itself establish FDA approval — the NDC Directory records that a product is listed with FDA, not that it was reviewed and approved. This listing's marketing category is "Unapproved Drug Other". Products approved under an application carry an NDA, ANDA, or BLA number.
Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
What does the discontinued status mean for this NDC?
The labeler reported a marketing end date (or the listing was delisted), so this specific package is no longer actively marketed. Remaining stock may still be dispensed for a time, and the NDC stays valid for historical records and claims — but data feeds (pricing, labeling) typically stop updating for it. Other package sizes or other manufacturers' versions of the same medication may still be marketed — see the equivalents section where available.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 79739-7372-1, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 79739-7372-01, written without dashes as 79739737201. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 79739-7372-01, the first segment (79739) is the labeler code FDA assigned to LGM PHARMA SOLUTIONS, LLC; the middle segment (7372) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (01) identifies this exact package size and type. Together they name one specific package of one specific product.
Who lists this product with the FDA?
LGM PHARMA SOLUTIONS, LLC is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage 126 words

INDICATIONS AND USAGE Thyroid Tablets, USP are indicated: 1. As replacement or supplemental therapy in patients with hypothyroidism of any etiology, except transient hypothyroidism during the recovery phase of subacute thyroiditis. This category includes cretinism, myxedema, and ordinary hypothyroidism in patients of any age (children, adults, the elderly), or state (including pregnancy); primary hypothyroidism resulting from functional deficiency, primary atrophy, partial or total absence of thyroid gland, or the effects of surgery, radiation, or drugs, with or without the presence of goiter; and secondary (pituitary), or tertiary (hypothalamic) hypothyroidism (See WARNINGS ).

2. As pituitary TSH suppressants, in the treatment or prevention of various types of euthyroid goiters, including thyroid nodules, subacute or chronic lymphocytic thyroiditis (Hashimoto’s), multinodular goiter, and in the management of thyroid cancer.

⏱️ Dosage and Administration ~3 min read

DOSAGE AND ADMINISTRATION The dosage of thyroid hormones is determined by the indication and must in every case be individualized according to patient response and laboratory findings. Thyroid hormones are given orally. In acute, emergency conditions, injectable levothyroxine sodium (T4) may be given intravenously when oral administration is not feasible or desirable, as in the treatment of myxedema coma, or during total parenteral nutrition.

Intramuscular administration is not advisable because of reported poor absorption. Hypothyroidism Therapy is usually instituted using low doses, with increments which depend on the cardiovascular status of the patient. The usual starting dose is 30 mg Thyroid Tablets, USP, with increments of 15 mg every 2 to 3 weeks.

A lower starting dosage, 15 mg/day, is recommended in patients with long-standing myxedema, particularly if cardiovascular impairment is suspected, in which case extreme caution is recommended. The appearance of angina is an indication for a reduction in dosage. Most patients require 60 to 120 mg/day.

Failure to respond to doses of 180 mg suggests lack of compliance or malabsorption. Maintenance dosages 60 to 120 mg/day usually result in normal serum T4 and T3 levels. Adequate therapy usually results in normal TSH and T4 levels after 2 to 3 weeks of therapy.

Readjustment of thyroid hormone dosage should be made within the first four weeks of therapy, after proper clinical and laboratory evaluations, including serum levels of T4, bound and free, and TSH. Liothyronine (T3) may be used in preference to levothyroxine (T4) during radio-isotope scanning procedures, since induction of hypothyroidism in those cases is more abrupt and can be of shorter duration. It may also be preferred when impairment of peripheral conversion of levothyroxine (T4) and liothyronine (T3) is suspected.

Myxedema Coma Myxedema coma is usually precipitated in the hypothyroid patient of long-standing by intercurrent illness or drugs such as sedatives and anesthetics and should be considered a medical emergency. Therapy should be directed at the correction of electrolyte disturbances and possible infection besides the administration of thyroid hormones. Corticosteroids should be administered routinely.

Levothyroxine (T4) and liothyronine (T3) may be administered via a nasogastric tube but the preferred route of administration of both hormones is intravenous. Levothyroxine sodium (T4) is given at a starting dose of 400 mcg (100 mcg/mL) given rapidly, and is usually well tolerated, even in the elderly. This initial dose is followed by daily supplements of 100 to 200 mcg given IV.

Normal T4 levels are achieved in 24 hours followed in 3 days by threefold elevation of T3. Oral therapy with thyroid hormone would be resumed as soon as the clinical situation has been stabilized and the patient is able to take oral medication. Thyroid Cancer Exogenous thyroid hormone may produce regression of metastases from follicular and papillary carcinoma of the thyroid and is used as ancillary therapy of these conditions with radioactive iodine.

TSH should be suppressed to low or undetectable levels. Therefore, larger amounts of thyroid hormone than those used for replacement therapy are required. Medullary carcinoma of the thyroid is usually unresponsive to this therapy.

Thyroid Suppression Therapy Administration of thyroid hormone in doses higher than those produced physiologically by the gland results in suppression of the production of endogenous hormone. This is the basis for the thyroid suppression test and is used as an aid in the diagnosis of patients with signs of mild hyperthyroidism in whom base line laboratory tests appear normal, or to demonstrate thyroid gland autonomy in patients with Grave’s ophthalmopathy. 131I uptake is determined before and after the administration of the exogenous hormone.

A 50% or greater suppression of uptake indicates a normal thyroid-pituitary axis and thus rules out thyroid gland autonom…

Contraindications 49 words

CONTRAINDICATIONS Thyroid hormone preparations are generally contraindicated in patients with diagnosed but as yet uncorrected adrenal cortical insufficiency, untreated thyrotoxicosis, and apparent hypersensitivity to any of their active or extraneous constituents. There is no well-documented evidence from the literature, however, of true allergic or idiosyncratic reactions to thyroid hormone.

⚠️ Warnings 151 words

WARNINGS Drugs with thyroid hormone activity, alone or together with other therapeutic agents, have been used for the treatment of obesity. 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.

The use of thyroid hormones in the therapy of obesity, alone or combined with other drugs, is unjustified and has been shown to be ineffective. Neither is their use justified for the treatment of male or female infertility unless this condition is accompanied by hypothyroidism. The active ingredient (desiccated natural thyroid) in Thyroid Tablets, USP is derived from porcine (pig) thyroid glands of pigs processed for human food consumption.

Vitruvias is not aware of any cases of disease transmission associated with the use of Thyroid Tablets, USP.

🤒 Adverse Reactions 26 words

ADVERSE REACTIONS Adverse reactions other than those indicative of hyperthyroidism because of therapeutic overdosage, either initially or during the maintenance period, are rare (See OVERDOSAGE ).

🔄 Drug Interactions ~1 min read

Drug Interactions Oral Anticoagulants—Thyroid hormones appear to increase catabolism of vitamin K-dependent clotting factors. If oral anticoagulants are also being given, compensatory increases in clotting factor synthesis are impaired. Patients stabilized on oral anticoagulants who are found to require thyroid replacement therapy should be watched very closely when thyroid is started.

If a patient is truly hypothyroid, it is likely that a reduction in anticoagulant dosage will be required. No special precautions appear to be necessary when oral anticoagulant therapy is begun in a patient already stabilized on maintenance thyroid replacement therapy. Insulin or Oral Hypoglycemics—Initiating thyroid replacement therapy may cause increases in insulin or oral hypoglycemic requirements.

The effects seen are poorly understood and depend upon a variety of factors such as dose and type of thyroid preparations and endocrine status of the patient. Patients receiving insulin or oral hypoglycemics should be closely watched during initiation of thyroid replacement therapy. Cholestyramine or Colestipol—Cholestyramine or colestipol binds both levothyroxine (T4) and liothyronine (T3) in the intestine, thus impairing absorption of these thyroid hormones.

In vitro studies indicate that the binding is not easily removed. Therefore four to five hours should elapse between administration of cholestyramine or colestipol and thyroid hormones. Estrogen, Oral Contraceptives—Estrogens tend to increase serum thyroxine-binding globulin (TBg).

In a patient with a nonfunctioning thyroid gland who is receiving thyroid replacement therapy, free levothyroxine (T4) may be decreased when estrogens are started thus increasing thyroid requirements. However, if the patient’s thyroid gland has sufficient function, the decreased free levothyroxine (T4) will result in a compensatory increase in levothyroxine (T4) output by the thyroid. Therefore, patients without a functioning thyroid gland who are on thyroid replacement therapy may need to increase their thyroid dose if estrogens or estrogen-containing oral contraceptives are given.

🧒 Pediatric Use 123 words

Pediatric Use Pregnant mothers provide little or no thyroid hormone to the fetus. The incidence of congenital hypothyroidism is relatively high (1:4,000) and the hypothyroid fetus would not derive any benefit from the small amounts of hormone crossing the placental barrier. Routine determinations of serum T4 and/or TSH is strongly advised in neonates in view of the deleterious effects of thyroid deficiency on growth and development.

Treatment should be initiated immediately upon diagnosis, and maintained for life, unless transient hypothyroidism is suspected; in which case, therapy may be interrupted for 2 to 8 weeks after the age of 3 years to reassess the condition. Cessation of therapy is justified in patients who have maintained a normal TSH during those 2 to 8 weeks.

🆘 Overdosage ~1 min read

OVERDOSAGE Signs and Symptoms Excessive doses of thyroid result in a hypermetabolic state resembling in every respect the condition of endogenous origin. The condition may be self-induced. Treatment of Overdosage Dosage should be reduced or therapy temporarily discontinued if signs and symptoms of overdosage appear.

Treatment may be reinstituted at a lower dosage. In normal individuals, normal hypothalamic-pituitary-thyroid axis function is restored in 6 to 8 weeks after thyroid suppression. Treatment of acute massive thyroid hormone overdosage is aimed at reducing gastrointestinal absorption of the drugs and counteracting central and peripheral effects, mainly those of increased sympathetic activity.

Vomiting may be induced initially if further gastrointestinal absorption can reasonably be prevented and barring contraindications such as coma, convulsions, or loss of the gagging reflex. Treatment is symptomatic and supportive. Oxygen may be administered and ventilation maintained.

Cardiac glycosides may be indicated if congestive heart failure develops. Measures to control fever, hypoglycemia, or fluid loss should be instituted if needed. Antiadrenergic agents, particularly propranolol, have been used advantageously in the treatment of increased sympathetic activity.

Propranolol may be administered intravenously at a dosage of 1 to 3 mg, over a 10-minute period or orally, 80 to 160 mg/day, initially, especially when no contraindications exist for its use. Other adjunctive measures may include administration of cholestyramine to interfere with thyroxine absorption, and glucocorticoids to inhibit conversion of T4 to T3.

🧬 Clinical Pharmacology ~2 min read

CLINICAL PHARMACOLOGY The steps in the synthesis of the thyroid hormones are controlled by thyrotropin (Thyroid Stimulating Hormone, TSH) secreted by the anterior pituitary. This hormone’s secretion is in turn controlled by a feedback mechanism effected by the thyroid hormones themselves and by thyrotropin releasing hormone (TRH), a tripeptide of hypothalamic origin. Endogenous thyroid hormone secretion is suppressed when exogenous thyroid hormones are administered to euthyroid individuals in excess of the normal gland’s secretion.

The mechanisms by which thyroid hormones exert their physiologic action are not well understood. These hormones enhance oxygen consumption by most tissues of the body, increase the basal metabolic rate, and the metabolism of carbohydrates, lipids, and proteins. Thus, they exert a profound influence on every organ system in the body and are of particular importance in the development of the central nervous system.

The normal thyroid gland contains approximately 200 mcg of levothyroxine (T4) per gram of gland, and 15 mcg of liothyronine (T3) per gram. The ratio of these two hormones in the circulation does not represent the ratio in the thyroid gland, since about 80% of peripheral liothyronine (T3) comes from monodeiodination of levothyroxine (T4). Peripheral monodeiodination of levothyroxine (T4) at the 5 position (inner ring) also results in the formation of reverse liothyronine (T3), which is calorigenically inactive.

Liothyronine (T3) levels are low in the fetus and newborn, in old age, in chronic caloric deprivation, hepatic cirrhosis, renal failure, surgical stress, and chronic illnesses representing what has been called the “T3 thyronine syndrome.” Pharmacokinetics Animal studies have shown that levothyroxine (T4) is only partially absorbed from the gastrointestinal tract. The degree of absorption is dependent on the vehicle used for its administration and by the character of the intestinal contents, the intestinal flora, including plasma protein, and soluble dietary factors, all of which bind thyroid and thereby make it unavailable for diffusion.

Only 41% is absorbed when given in a gelatin capsule as opposed to a 74% absorption when given with an albumin carrier. Depending on other factors, absorption has varied from 48 to 79% of the administered dose. Fasting increases absorption.

Malabsorption syndromes, as well as dietary factors, (children’s soybean formula, concomitant use of anionic exchange resins such as cholestyramine) cause excessive fecal loss. Liothyronine (T3) is almost totally absorbed, 95 % in 4 hours. The hormones contained in the natural preparations are absorbed in a manner similar to the synthetic hormones.

More than 99% of circulating hormones are bound to serum proteins, including thyroid-binding globulin (TBg), thyroid-binding prealbumin (TBPA), and albumin (TBa), whose capacities and affinities vary for the hormones. The higher affinity of levothyroxine (T4) for both TBg and TBPA as compared to liothyronine (T3) partially explains the higher serum levels and longer half-life of the former hormone. Both protein-bound hormones exist in reverse equilibrium with minute amounts of free hormone, the latter accounting for the metabolic activity.

Deiodination of levothyroxine (T4) occurs at a number of sites, including liver, kidney, and other tissues. The conjugated hormone, in the form of glucuronide or sulfate, is found in the bile and gut where it may complete an enterohepatic circulation. 85% of levothyroxine (T4) metabolized daily is deiodinated.

📦 How Supplied / Storage and Handling ~1 min read

HOW SUPPLIED Thyroid Tablets, USP are supplied as follows: 15 mg (1/4 grain) are available in bottles of 100 (NDC 79739-7370-1). 30 mg (1/2 grain) are available in bottles of 100 (NDC 79739-7371-1). 60 mg (1 grain) are available in bottles of 100 (NDC 79739-7372-1).

90 mg (1 & 1/2 grain) are available in bottles of 100 (NDC 79739-7373-1). 120 mg (2 grain) are available in bottles of 100 (NDC 79739-7374-1). The bottles of 100 have child-resistant closures.

Thyroid Tablets, USP is an off-white to pale brown, round tablet, which may display flecks. The 15 mg and 30 mg tablets are flat-faced with a bevel edge, and the 60 mg, 90 mg, and 120 mg tablets have concave faces. One side is debossed with the letters "THY" and the other side with the strength code numbers as defined below.

Strength Code ¼ grain 025 ½ grain 050 1 grain 100 1 ½ grain 150 2 grain 200 Note: (T3 liothyronine is approximately four times as potent as T4 levothyroxine on a microgram for microgram basis.) Store in a tight container protected from light and moisture. Store between 15°C and 30°C (59°F and 86°F). *Thyroid Tablets, USP has not been approved by FDA as a new drug. All prescription substitutions and/or recommendations using this product shall be made subject to state and federal statutes as applicable.

Please note: this is not an Orange Book product and has not been subjected to FDA therapeutic equivalency or other equivalency testing. No representation is made as to generic status or bioequivalency. Each person recommending a prescription substitution using this product shall make such recommendations based on each such person’s professional opinion and knowledge, upon evaluating the active ingredients, excipients, inactive ingredients and chemical information provided herein.

Manufactured by: LGM Pharma Solutions, LLC Irvine, CA 92614 Product of USA 7370-0000-99-OS-PD Rev 01/2024

📋 Description 79 words

DESCRIPTION Thyroid Tablets, USP* for oral use is a natural preparation derived from porcine thyroid glands and may have a strong, characteristic odor. (T3 liothyronine is approximately four times as potent as T4 levothyroxine on a microgram for microgram basis.) They provide 38 mcg levothyroxine (T4) and 9 mcg liothyronine (T3) per grain of thyroid. The inactive ingredients are microcrystalline cellulose, lactose, silicon dioxide, and magnesium stearate.

An image of the structural formulas of liothyronine (T3) and levothyroxine (T4)

💬 Information for Patients 206 words

Information for the Patient Patients on thyroid hormone preparations and parents of children on thyroid therapy should be informed that: 1. Replacement therapy is to be taken essentially for life, with the exception of cases of transient hypothyroidism, usually associated with thyroiditis, and in those patients receiving a therapeutic trial of the drug. 2.

They should immediately report during the course of therapy any signs or symptoms of thyroid hormone toxicity, e.g., chest pain, increased pulse rate, palpitations, excessive sweating, heat intolerance, nervousness, or any other unusual event. 3. In case of concomitant diabetes mellitus, the daily dosage of antidiabetic medication may need readjustment as thyroid hormone replacement is achieved.

If thyroid medication is stopped, a downward readjustment of the dosage of insulin or oral hypoglycemic agent may be necessary to avoid hypoglycemia. At all times, close monitoring of urinary glucose levels is mandatory in such patients. 4.

In case of concomitant oral anticoagulant therapy, the prothrombin time should be measured frequently to determine if the dosage of oral anticoagulants is to be readjusted. 5. Partial loss of hair may be experienced by children in the first few months of thyroid therapy, but this is usually a transient phenomenon and later recovery is usually the rule.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
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