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Methimazole 5 mg Tablet, 1,000-count — NDC 23155-0070-10 package photo

Methimazole 5 mg Tablet, 1,000-count

by Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. · 1000 TABLET in 1 BOTTLE (23155-070-10)
NDC 23155-0070-10
🏷️ FDA NDC (as labeled) 23155-070-10 billing pads the product segment with a zero
This package
Contains1,000-count Pack sizes2 compare ↓
Also priced by: Part D plans $0.1781/unit — full pricing hub ↓
Also comes in: 100 tablets 23155-0070-01
Rx only Generic On market Non-controlled
🗂️ 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 →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

🆔 Identity & classification

FDA NDC (as labeled) 23155-070-10
Product NDC 23155-070
11-digit billing NDC 23155007010
RxCUI 197941, 197942
UNII 554Z48XN5E
UPC 0323155071016, 0323155070019
Application # ANDA040734
SPL Set ID 8c3a9aaa-cdde-404b-9af6-5a88ef649aac
Established class (EPC) Thyroid Hormone Synthesis Inhibitor
Mechanism of action Thyroid Hormone Synthesis Inhibitors
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2012-01-15
Route ORAL
Dosage form TABLET
Substance METHIMAZOLE
GPI-14 28300010000305
GPI class methIMAzole
GCN Seq No 006675
GCN 26401
HICL code 002855
Ingredient (HICL) Methimazole
HIC1 code P
Therapeutic class — broad (HIC1) Endocrine System
HIC2 code P3
Therapeutic class — intermediate (HIC2) Drugs Affecting Thyroid Function
HIC3 code P3L
Therapeutic class — specific (HIC3) Antithyroid Preparations
AHFS code 68:36.08.00
AHFS class Antithyroid Agents
FDB label name METHIMAZOLE 5 MG TABLET
FDB brand name Methimazole
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 23155-070-10 — a 5-3-2 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 product segment → 23155-0070-10. 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.

🏷️ RxNorm drug class

This medicine belongs to the Thyroid Hormone Synthesis Inhibitor class.

Pharmacologic class Thyroid Hormone Synthesis Inhibitor
Drug family (ATC) Sulfur-containing imidazole derivatives
How it works Thyroid Hormone Synthesis Inhibitors
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerHeritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.
Application holderHERITAGE PHARMA LABS INC
FDA applicationANDA040734 (ANDA)
Labeler code23155
First marketedJan 2012
Product typeHuman Prescription Drug
Portfolio253 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

Label name METHIMAZOLE 5 MG TABLET Ingredient Methimazole
📗 Our plain-language guide HelloPharmacist
  • Methimazole tells your thyroid gland to stop making so much thyroid hormone. When your thyroid is overactive — like in Graves' disease — it pumps out too much hormone and speeds ev...
  • What exactly is methimazole supposed to do for me?
  • Usually you'll take it in three separate doses spaced about 8 hours apart throughout the day — so think morning, afternoon, and evening. Your prescriber sets the exact dose based o...
  • How do I take it — do I take it all at once?
📖 Read our full Methimazole 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.

💊 What it looks like

Color White
ShapeRound
ImprintHP;71
Size8 mm
ScoringScored — splits in 2
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 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.

  • UNII EWQ57Q8I5X
    Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
  • UNII 70097M6I30
    Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
  • UNII O8232NY3SJ
    A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
  • UNII 7SEV7J4R1U
    A powder made from a naturally occurring mineral. In medicines, talc works as a glidant and anti-caking agent, helping tablets and capsules flow smoothly during manufacturing and preventing clumping.

4 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMed — 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

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 · Q2 2026 $0.1781 $178.10 / 1000 tablets
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
Methimazole 5 mg 00832-6072-11 Upsher-Smith 100 tablets $0.071 AB Availability likely —
Methimazole 5 mg 11788-0011-01 AiPing 100 tablets $0.071 AB Availability likely —
Methimazole 5 mg 33342-0335-11 Macleods 100 tablets $0.071 AB Availability likely —
Methimazole 5 mg 50268-0495-15 AvPAK 50 tablets $0.071 AB Availability likely —
Methimazole 5 mg 60687-0669-01 American 100 tablets $0.071 AB Availability likely —
Methimazole 5 mg 64380-0212-01 Strides 100 tablets $0.071 AB Availability likely —
Methimazole 5 mg 64980-0264-01 Rising 100 tablets $0.071 AB Availability likely —
Methimazole 5 mg 69452-0328-20 Bionpharma 100 tablets $0.071 AB Availability likely —
methimazole 5 mg 72578-0212-01 Viona 100 tablets $0.071 AB Availability likely —
Methimazole 5 mg 72603-0315-01 NORTHSTAR 100 tablets $0.071 AB Availability likely —
Methimazole 5 mgthis 23155-0070-10 Heritage 1000 tablets — AB FDA listed —
Methimazole 5 mg 50090-6536-00 A-S 90 tablets — AB FDA listed —
Methimazole 5 mg 60429-0380-01 Golden 100 tablets — AB FDA listed —
Methimazole 5 mg 62135-0205-01 Chartwell 100 tablets — AB FDA listed —
Methimazole 5 mg 63629-8347-01 Bryant 30 tablets — AB FDA listed —
Methimazole 5 mg 63629-9249-01 Bryant 100 tablets — AB FDA listed —
Methimazole 5 mg 63629-9250-01 Bryant 500 tablets — AB FDA listed —
methimazole 5 mg 67046-1651-03 Coupler 30 tablets — AB FDA listed —
Methimazole 5 mg 68788-8226-03 Preferred 30 tablets — AB FDA listed —
Methimazole 5 mg 68788-8883-01 Preferred 100 tablets — AB FDA listed —
Methimazole 5 mg 70518-1506-00 REMEDYREPACK 30 tablets — AB FDA listed —
Methimazole 5 mg 71335-2881-01 Bryant 100 tablets — AB FDA listed —
Methimazole 5 mg 71335-3026-01 Bryant 500 tablets — AB FDA listed —
Methimazole 5 mg 72162-1802-01 Bryant 100 tablets — AB FDA listed —
Methimazole 5 mg 73190-0084-01 AvKARE 100 tablets — AB FDA listed —
methimazole 5 mg 76483-0082-00 SQUARE 100 tablets — AB FDA listed —
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
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

🏛️
2012
On the market since
Jan 2012
📍
2026
Currently FDA-listed
14 years listed
🔓
·
Generic on the market
this product is a generic
✅This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

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.

💊 Medicaid utilization by pack size

Medicaid (SDUD) totals over the four most recent reported quarters for every package size of this drug — handy when a specific package (e.g. a starter/titration pack) carries little or no Medicaid volume on its own.
100 tablets23155-0070-01 95,292 Rx · $1,141,035
1000 tablets this page23155-0070-10 No Medicaid data
Drug total (last 4 qtrs): 95,292 Rx · 4,473,719 units · $1,141,035 gross reimbursed
Tap a pack size to open its page. Source: CMS State Drug Utilization Data, last 4 quarters.

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

Medicare Part D (outpatient prescription) spending for Methimazole — the program that covers self-administered drugs. 10 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 Methimazole. 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
$2.92M
Claims incl. refills
257.2K
Beneficiaries
179.3K
Spend / beneficiary
$16.29
Spend / claim
$11.35
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.

📦 Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startStatus
23155-0070-01 100 TABLET in 1 BOTTLE (23155-070-01) $0.0707 / ea $7.07 2012-01-15 Active
23155-0070-10 You're viewing this 1000 TABLET in 1 BOTTLE (23155-070-10) — — 2012-01-15 Active

You're viewing the largest of 2 pack sizes for this product.

This pack shows little to no recent Medicaid volume — the 100 tablets pack carries most fills. See all packs ↓

Pack size FAQ

What quantity is in NDC 23155-0070-10?
NDC 23155-0070-10 is a 1,000-count package — 1000 tablet in 1 bottle.
What is the difference between NDC 23155-0070-10 and NDC 23155-0070-01?
Both are Methimazole 5 mg Tablet — the drug itself is identical. NDC 23155-0070-10 is the 1,000-count package, while NDC 23155-0070-01 is the 100 tablets package.
What NDC number is used to bill for this package of Methimazole 5 mg Tablet?
Bill NDC 23155-0070-10 — the 11-digit billing format is 23155007010. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

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

Finished prescription product
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 — 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

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.
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 23155-070-10, 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: 23155-0070-10, written without dashes as 23155007010. 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 23155-0070-10, the first segment (23155) is the labeler code FDA assigned to Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.; the middle segment (0070) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (10) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 1 other package presentation of this same product, including 100 tablets (23155-0070-01). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. 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 ⏱️ Dosage and Administration ⛔ Contraindications ⚠️ Warnings 🤒 Adverse Reactions 🔄 Drug Interactions 🤰 Pregnancy 🧒 Pediatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients
🎯 Indications and Usage 44 words ▾

INDICATIONS AND USAGE Methimazole tablets are indicated: In patients with Graves' disease with hyperthyroidism or toxic multinodular goiter for whom surgery or radioactive iodine therapy is not an appropriate treatment option. To ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy.

⏱️ Dosage and Administration 96 words ▾

DOSAGE AND ADMINISTRATION Methimazole tablets are administered orally. The total daily dosage is usually given in 3 divided doses at approximately 8-hour intervals. Adult - The initial daily dosage is 15 mg for mild hyperthyroidism, 30 to 40 mg for moderately severe hyperthyroidism, and 60 mg for severe hyperthyroidism, divided into 3 doses at 8-hour intervals.

The maintenance dosage is 5 to 15 mg daily. Pediatric - Initially, the daily dosage is 0.4 mg/kg of body weight divided into 3 doses and given at 8-hour intervals. The maintenance dosage is approximately 1/2 of the initial dose.

⛔ Contraindications 20 words ▾

CONTRAINDICATIONS Methimazole tablets are contraindicated in the presence of hypersensitivity to the drug or any of the other product components.

⚠️ Warnings ~2 min read ▾

WARNINGS First Trimester Use of Methimazole and Congenital Malformations Methimazole crosses the placental membranes and can cause fetal harm, when administered in the first trimester of pregnancy. Rare instances of congenital defects, including aplasia cutis, craniofacial malformations (facial dysmorphism; choanal atresia), gastrointestinal malformations (esophageal atresia with or without tracheoesophageal fistula) omphalocele and abnormalities of the omphalomesenteric duct have occurred in infants born to mothers who received methimazole tablets in the first trimester of pregnancy.

If methimazole tablets are used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be warned of the potential hazard to the fetus. Because of the risk for congenital malformations associated with use of methimazole tablets in the first trimester of pregnancy it may be appropriate to use other agents in pregnant women requiring treatment for hyperthyroidism. If methimazole tablets are used, the lowest possible dose to control the maternal disease should be given.

Agranulocytosis Agranulocytosis is potentially a life-threatening adverse reaction of methimazole therapy. Patients should be instructed to immediately report to their physicians any symptoms suggestive of agranulocytosis, such as fever or sore throat. Leukopenia, thrombocytopenia, and aplastic anemia (pancytopenia) may also occur.

The drug should be discontinued in the presence of agranulocytosis or aplastic anemia (pancytopenia), and the patient's bone marrow indices should be monitored. Liver Toxicity Although there have been reports of hepatotoxicity (including acute liver failure) associated with methimazole, the risk of hepatotoxicity appears to be less with methimazole than with propylthiouracil, especially in the pediatric population. Symptoms suggestive of hepatic dysfunction (anorexia, pruritis, right upper quadrant pain, etc.) should prompt evaluation of liver function (bilirubin, alkaline phosphatase) and hepatocellular integrity (ALT, AST).

Drug treatment should be discontinued promptly in the event of clinically significant evidence of liver abnormality including hepatic transaminase values exceeding 3 times the upper limit of normal. Hypothyroidism Methimazole can cause hypothyroidism necessitating routine monitoring of TSH and free T4 levels with adjustments in dosing to maintain a euthyroid state. Because the drug readily crosses placental membranes, methimazole can cause fetal goiter and cretinism when administered to a pregnant woman.

For this reason, it is important that a sufficient, but not excessive, dose be given during pregnancy (see PRECAUTIONS, Pregnancy ). Vasculitis Cases of vasculitis resulting in severe complications have been reported in patients receiving methimazole therapy. These cases of vasculitis include: leukocytoclastic cutaneous vasculitis, acute kidney injury and glomerulonephritis, alveolar/pulmonary hemorrhage, CNS vasculitis, and neuropathy.

Most cases were associated with anti-neutrophilic cytoplasmic antibodies (ANCA)-positive vasculitis. In some cases, vasculitis resolved/improved with drug discontinuation; however, more severe cases required treatment with additional measures including corticosteroids, immunosuppressant therapy, and plasmapheresis. If vasculitis is suspected, discontinue therapy and initiate appropriate intervention.

🤒 Adverse Reactions 124 words ▾

ADVERSE REACTIONS Major adverse reactions (which occur with much less frequency than the minor adverse reactions) include inhibition of myelopoiesis (agranulocytosis, granulocytopenia, thrombocytopenia, and aplastic anemia), drug fever, a lupus-like syndrome, insulin autoimmune syndrome (which can result in hypoglycemic coma), hepatitis (jaundice may persist for several weeks after discontinuation of the drug), periarteritis, and hypoprothrombinemia. Nephritis occurs very rarely. There have been postmarketing case reports of acute pancreatitis.

There are reports of a vasculitis, often associated with the presence of anti-neutrophilic cytoplasmic antibodies (ANCA), resulting in severe complications (see WARNINGS ). Minor adverse reactions include skin rash, urticaria, nausea, vomiting, epigastric distress, arthralgia, paresthesia, loss of taste, abnormal loss of hair, myalgia, headache, pruritus, drowsiness, neuritis, edema, vertigo, skin pigmentation, jaundice, sialadenopathy, and lymphadenopathy.

🔄 Drug Interactions 118 words ▾

Drug Interactions Anticoagulants (oral): Due to potential inhibition of vitamin K activity by methimazole, the activity of oral anticoagulants (e.g., warfarin) may be increased; additional monitoring of PT/INR should be considered, especially before surgical procedures. β-adrenergic blocking agents: Hyperthyroidism may cause an increased clearance of beta blockers with a high extraction ratio. A dose reduction of beta-adrenergic blockers may be needed when a hyperthyroid patient becomes euthyroid. Digitalis glycosides: Serum digitalis levels may be increased when hyperthyroid patients on a stable digitalis glycoside regimen become euthyroid; a reduced dosage of digitalis glycosides may be needed.

Theophylline: Theophylline clearance may decrease when hyperthyroid patients on a stable theophylline regimen become euthyroid; a reduced dose of theophylline may be needed.

🤰 Pregnancy 204 words ▾

Pregnancy See WARNINGS If methimazole tablets are used during the first trimester of pregnancy or if the patient becomes pregnant while taking this drug, the patient should be warned of the potential hazard to the fetus. In pregnant women with untreated or inadequately treated Graves' disease, there is an increased risk of adverse events of maternal heart failure, spontaneous abortion, preterm birth, stillbirth and fetal or neonatal hyperthyroidism. Because methimazole crosses placental membranes and can induce goiter and cretinism in the developing fetus, hyperthyroidism should be closely monitored in pregnant women and treatment adjusted such that a sufficient, but not excessive, dose be given during pregnancy.

In many pregnant women, the thyroid dysfunction diminishes as the pregnancy proceeds; consequently, a reduction of dosage may be possible. In some instances, anti-thyroid therapy can be discontinued several weeks or months before delivery. Due to the rare occurrence of congenital malformations associated with methimazole use, it may be appropriate to use an alternative anti-thyroid medication in pregnant women requiring treatment for hyperthyroidism particularly in the first trimester of pregnancy during organogenesis.

Given the potential maternal adverse effects of propylthiouracil (e.g., hepatotoxicity), it may be preferable to switch from propylthiouracil to methimazole for the second and third trimesters.

🧒 Pediatric Use 36 words ▾

Pediatric Use Because of postmarketing reports of severe liver injury in pediatric patient treated with propylthiouracil, methimazole is the preferred choice when an antithyroid drug is required for a pediatric patient (see DOSAGE AND ADMINISTRATION ).

🆘 Overdosage 129 words ▾

OVERDOSAGE Signs and Symptoms Symptoms may include nausea, vomiting, epigastric distress, headache, fever, joint pain, pruritus, and edema. Aplastic anemia (pancytopenia) or agranulocytosis may be manifested in hours to days. Less frequent events are hepatitis, nephrotic syndrome, exfoliative dermatitis, neuropathies, and CNS stimulation or depression.

No information is available on the median lethal dose of the drug or the concentration of methimazole in biologic fluids associated with toxicity and/or death. Treatment To obtain up-to-date information about the treatment of overdose, a good resource is your certified Regional Poison Control Center. In managing overdosage, consider the possibility of multiple drug overdoses, interaction among drugs, and unusual drug kinetics in the patient.

In the event of an overdose, appropriate supportive treatment should be initiated as dictated by the patient's medical status.

🧬 Clinical Pharmacology 71 words ▾

CLINICAL PHARMACOLOGY Methimazole inhibits the synthesis of thyroid hormones and thus is effective in the treatment of hyperthyroidism. The drug does not inactivate existing thyroxine and tri-iodothyronine that are stored in the thyroid or circulating in the blood nor does it interfere with the effectiveness of thyroid hormones given by mouth or by injection. Methimazole is readily absorbed in the gastrointestinal tract, metabolized in the liver, and excreted in the urine.

📦 How Supplied / Storage and Handling 124 words ▾

HOW SUPPLIED Methimazole tablets, USP 5 mg - round, white to off white bi-convex tablet. Debossed HP bisect 70 on one side and plain on the reverse side. They are available in: Bottles of 100 NDC 23155-070-01 Bottles of 1000 NDC 23155-070-10 Methimazole tablets, USP 10 mg - round, white to off white bi-convex tablet.

Debossed HP bisect 71 on one side and plain on the reverse side. They are available in: Bottles of 100 NDC 23155-071-01 Bottles of 1000 NDC 23155-071-10 Store at 20° to 25°C (68° to 77°F); excursions permitted between 15° to 30°C (59° to 86°F) [See USP Controlled Room Temperature]. Dispense in tight, light-resistant container.

Distributed by: Avet Pharmaceuticals Inc. East Brunswick, NJ 08816 1.866.901.DRUG (3784) 51U000000174US06 Revised: 01/2022 logo

📋 Description 89 words ▾

DESCRIPTION Methimazole (1-methylimidazole-2-thiol) is a white, crystalline substance that is freely soluble in water. It differs chemically from the drugs of the thiouracil series primarily because it has a 5- instead of a 6-membered ring. Methimazole tablet, USP contains 5 or 10 mg (43.8 or 87.6 μmol) methimazole, an orally administered antithyroid drug.

Each tablet also contains lactose monohydrate, magnesium stearate, pregelatinized starch and talc. The molecular weight is 114.16, and the molecular formula is C 4 H 6 N 2 S. The structural formula is as follows: structure

💬 Information for Patients 75 words ▾

Information for Patients Patients should be advised that if they become pregnant or intend to become pregnant while taking an antithyroid drug, they should contact their physician immediately about their therapy. Inform patients that cases of vasculitis resulting in severe complications have occurred with methimazole tablets. Inform patients to promptly report symptoms that may be associated with vasculitis including new rash, hematuria or decreased urine output, dyspnea or hemoptysis (see WARNINGS and ADVERSE REACTIONS ).

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
← 23155-0059-01 · Heritage 23155-0071-01 · Heritage →
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.