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Azulfidine Sulfasalazine 500 mg Tablet, 300-count

by Pfizer Laboratories Div Pfizer Inc · 1 BOTTLE in 1 CARTON (0013-0101-30) / 300 TABLET in 1 BOTTLE
NDC 00013-0101-30
🏷️ FDA NDC (as labeled) 0013-0101-30 billing pads the labeler segment with a zero
This package
Contains300-count Pack sizes4 compare ↓
Also priced by: Part D plans $1.64/unit — full pricing hub ↓
Rx only Brand 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 →

🆔 Identity & classification

FDA NDC (as labeled) 0013-0101-30
Product NDC 0013-0101
11-digit billing NDC 00013010130
NCPDP billing unit EA — each (per item)
RxCUI 198232, 208437
UNII 3XC8GUZ6CB
UPC 0300130101012
Application # NDA007073
SPL Set ID ddbe69f3-bd55-45f3-a64f-f60226c744c4
Established class (EPC) Aminosalicylate
Chemical class Aminosalicylic Acids
DEA schedule Non-controlled
Marketing category NDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 1950-06-20
Route ORAL
Dosage form TABLET
Substance SULFASALAZINE
GPI-14 52500060000310
GPI class Azulfidine
GCN Seq No 009402
GCN 41611
HICL code 004074
Ingredient (HICL) Sulfasalazine
HIC1 code D
Therapeutic class — broad (HIC1) Biliary System/Gastro-Intestinal System
HIC2 code D6
Therapeutic class — intermediate (HIC2) Drugs Acting Principally On The Colon
HIC3 code D6F
Therapeutic class — specific (HIC3) Drug Tx-Chronic Inflam. Colon Dx,5-Aminosalicylat
AHFS code 08:12.20.00
AHFS class Sulfonamides
FDB label name AZULFIDINE 500 MG TABLET
FDB brand name Azulfidine
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 0013-0101-30 — a 4-4-2 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 labeler segment → 00013-0101-30. 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 Aminosalicylate class.

Pharmacologic class Aminosalicylate
Drug family (ATC) Aminosalicylic acid and similar agents
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

LabelerPfizer Laboratories Div Pfizer Inc
Application holderPFIZER INC
FDA applicationNDA007073 (NDA)
Labeler code00013
First marketedJun 1950
Product typeHuman Prescription Drug
Portfolio242 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 AZULFIDINE 500 MG TABLET Ingredient Sulfasalazine
📖 What it is MedlinePlus · NLM

Sulfasalazine is used to treat ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum) and also to maintain improvement of ulcerative colitis symptoms. Sulfasalazine delayed-release (Azulfidine EN-tabs) is also used to treat rheumatoid arthritis in adults whose disease has not responded well to other medications or could not be tolerated. Sulfasalazine delayed-release (Azulfidine EN-tabs) is also used to treat polyarticular juvenile idiopathic arthritis (PJIA; a type of childhood arthritis that affects five or more joints during...

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • Sulfasalazine is mainly used to treat ulcerative colitis — it helps calm flares and keep the disease in remission. The delayed-release tablet form is also approved for rheumatoid a...
  • What is sulfasalazine actually used for?
  • For ulcerative colitis, improvement can vary from person to person. For rheumatoid arthritis, it's important to know that the delayed-release form does not produce an immediate res...
  • The most common side effects are nausea, stomach upset, loss of appetite, and headache — these happen in roughly a third of people and are often worse at higher doses. You might al...
📖 Read our full Sulfasalazine guide →
1
Nutrient depletion considerations

Sulfasalazine may be associated with lower levels of 1 nutrient — worth a chat with your pharmacist, not a cause for alarm.

An association is not a deficiency. Educational only — don't start or stop anything without professional guidance.
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 Yellow
ShapeRound
Imprint101;KPh
Size14 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 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 FZ989GH94E
    Povidone is a synthetic polymer made from a plastic-like material. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in your stomach so the medicine can be absorbed.
  • UNII ETJ7Z6XBU4
    Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
  • 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.

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 DailyMedingredient 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 $1.64 $491.28 / 300 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
Sulfasalazine 500 mg 59762-5000-01 Mylan 100 tablets $0.174 AB Discontinued
Sulfasalazine 500 mg 00093-3234-01 Teva 100 tablets $0.200 AB Availability likely
Sulfasalazine 500 mg 11534-0200-01 Sunrise 100 tablets $0.200 AB Availability likely
Sulfasalazine 500 mg 62135-0960-01 Chartwell 100 tablets $0.200 AB Availability likely
Azulfidine 500 mgthis 00013-0101-30 Pfizer 300 tablets AB FDA listed
Sulfasalazine 500 mg 16571-0261-01 Rising 100 tablets AB FDA listed
Sulfasalazine 500 mg 50090-0086-00 A-S 50 tablets AB Discontinued
Sulfasalazine 500 mg 50090-6936-00 A-S 90 tablets AB FDA listed
Sulfasalazine 500 mg 63629-9715-01 Bryant 90 tablets AB FDA listed
Sulfasalazine 500 mg 70518-1829-02 REMEDYREPACK 30 tablets AB Discontinued
Sulfasalazine 500 mg 71610-0706-70 Aphena 120 tablets AB FDA listed
Sulfasalazine 500 mg 60687-0932-01 American 100 tablets AB Discontinued
About this product: this is the brand-name version. FDA-approved generic versions are listed, and recent pricing/market data suggests they may be 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

🏛️
1950
On the market since
Jun 1950
📍
2026
Currently FDA-listed
76 years listed
🔓
·
Generic versions listed
see equivalents
Generic appears available

FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available — see Therapeutic equivalents.

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 Azulfidine — the program that covers self-administered drugs. 1 manufacturer.
⚠️ 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 Azulfidine. 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
$50.9K
Claims incl. refills
123
Beneficiaries
95
Spend / beneficiary
$535.75
Spend / claim
$413.79
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 Marketing startStatus
00013-0101-01 100 TABLET in 1 BOTTLE (0013-0101-01) 1950-06-20 Discontinued by firm
00013-0101-10 1 BOTTLE in 1 CARTON (0013-0101-10) / 100 TABLET in 1 BOTTLE 2020-02-27 Active
00013-0101-20 300 TABLET in 1 BOTTLE (0013-0101-20) 1950-06-20 Discontinued by firm
00013-0101-30 You're viewing this 1 BOTTLE in 1 CARTON (0013-0101-30) / 300 TABLET in 1 BOTTLE 2020-02-27 Active

Pack size FAQ

What quantity is in NDC 00013-0101-30?
NDC 00013-0101-30 is a 300-count package — 1 bottle in 1 carton / 300 tablet in 1 bottle.
What is the difference between NDC 00013-0101-30 and NDC 00013-0101-01?
Both are Azulfidine Sulfasalazine 500 mg Tablet — the drug itself is identical. NDC 00013-0101-30 is the 300-count package, while NDC 00013-0101-01 is the 100 tablets package.
What NDC number is used to bill for this package of Azulfidine Sulfasalazine 500 mg Tablet?
Bill NDC 00013-0101-30 — the 11-digit billing format is 00013010130. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

🧭 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 — Not published for this NDC No photo available yet for this listing.
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 0013-0101-30, 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: 00013-0101-30, written without dashes as 00013010130. 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 00013-0101-30, the first segment (00013) is the labeler code FDA assigned to Pfizer Laboratories Div Pfizer Inc; the middle segment (0101) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (30) 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 Pfizer Laboratories Div Pfizer 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 3 other package presentations of this same product, including 100 tablets (00013-0101-01), 100 tablets (00013-0101-10), 300 tablets (00013-0101-20). 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?
Pfizer Laboratories Div Pfizer 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 40 words

INDICATIONS AND USAGE AZULFIDINE Tablets are indicated: • in the treatment of mild to moderate ulcerative colitis, and as adjunctive therapy in severe ulcerative colitis; and • for the prolongation of the remission period between acute attacks of ulcerative colitis.

⏱️ Dosage and Administration ~2 min read

DOSAGE AND ADMINISTRATION The dosage of AZULFIDINE Tablets should be adjusted to each individual's response and tolerance. Initial Therapy Adults: 3 to 4 g daily in evenly divided doses with dosage intervals not exceeding eight hours. In some cases, it is advisable to initiate therapy with a smaller dosage, e.g., 1 to 2 g daily, to reduce possible gastrointestinal intolerance.

If daily doses exceeding 4 g are required to achieve desired effects, the increased risk of toxicity should be kept in mind. Children, six years of age and older: 40 to 60 mg/kg body weight in each 24-hour period, divided into 3 to 6 doses. Maintenance Therapy Adults: 2 g daily.

Children, six years of age and older: 30 mg/kg body weight in each 24-hour period, divided into 4 doses. The response of acute ulcerative colitis to AZULFIDINE Tablets can be evaluated by clinical criteria, including the presence of fever, weight changes, and degree and frequency of diarrhea and bleeding, as well as by sigmoidoscopy and the evaluation of biopsy samples. It is often necessary to continue medication even when clinical symptoms, including diarrhea, have been controlled.

When endoscopic examination confirms satisfactory improvement, the dosage of AZULFIDINE should be reduced to a maintenance level. If diarrhea recurs, the dosage should be increased to previously effective levels. If symptoms of gastric intolerance (anorexia, nausea, vomiting, etc.) occur after the first few doses of AZULFIDINE, they are probably due to increased serum levels of total sulfapyridine and may be alleviated by halving the daily dose of AZULFIDINE and subsequently increasing it gradually over several days.

If gastric intolerance continues, the drug should be stopped for 5 to 7 days, then reintroduced at a lower daily dose. Some patients may be sensitive to treatment with sulfasalazine. Various desensitization-like regimens have been reported to be effective in 34 of 53 patients, 4 7 of 8 patients, 5 and 19 of 20 patients.

6 These regimens suggest starting with a total daily dose of 50 to 250 mg sulfasalazine initially, and doubling it every 4 to 7 days until the desired therapeutic level is achieved. If the symptoms of sensitivity recur, AZULFIDINE should be discontinued. Desensitization should not be attempted in patients who have a history of agranulocytosis, or who have experienced an anaphylactoid reaction while previously receiving sulfasalazine.

Contraindications 34 words

CONTRAINDICATIONS AZULFIDINE Tablets are contraindicated in: Patients with intestinal or urinary obstruction, Patients with porphyria as sulfonamides have been reported to precipitate an acute attack, Patients hypersensitive to sulfasalazine, its metabolites, sulfonamides, or salicylates.

⚠️ Warnings ~2 min read

WARNINGS Hepatic, Renal, and Hematologic Toxicity or Other Conditions Only after critical appraisal should AZULFIDINE Tablets be given to patients with hepatic or renal damage or blood dyscrasias. Deaths associated with the administration of sulfasalazine have been reported from hypersensitivity reactions, agranulocytosis, aplastic anemia, other blood dyscrasias, renal and liver damage, irreversible neuromuscular and central nervous system changes, and fibrosing alveolitis. The presence of clinical signs such as sore throat, fever, pallor, purpura, or jaundice may be indications of serious blood disorders or hepatotoxicity.

Complete blood counts, as well as urinalysis with careful microscopic examination, should be done frequently in patients receiving AZULFIDINE (see PRECAUTIONS, Laboratory Tests ). Discontinue treatment with sulfasalazine while awaiting the results of blood tests. Discontinue AZULFIDINE if renal function deteriorates while on therapy.

Oligospermia and Infertility Oligospermia and infertility have been observed in men treated with sulfasalazine; however, withdrawal of the drug appears to reverse these effects. Serious Infections Serious infections, including fatal sepsis and pneumonia, have been reported. Some infections were associated with agranulocytosis, neutropenia, or myelosuppression.

Discontinue AZULFIDINE if a patient develops a serious infection. Closely monitor patients for the development of signs and symptoms of infection during and after treatment with AZULFIDINE. For a patient who develops a new infection during treatment with AZULFIDINE, perform a prompt and complete diagnostic workup for infection and myelosuppression.

Caution should be exercised when considering the use of sulfasalazine in patients with a history of recurring or chronic infections or with underlying conditions or concomitant drugs which may predispose patients to infections. Hypersensitivity Reactions Severe hypersensitivity reactions may include internal organ involvement, such as hepatitis, nephritis, myocarditis, mononucleosis-like syndrome (i.e., pseudomononucleosis), hematological abnormalities (including hematophagic histiocytosis), and/or pneumonitis including eosinophilic infiltration.

Severe Cutaneous Adverse Reactions Drug Reactions with Eosinophilia and Systemic Symptoms (DRESS) Severe, life-threatening, systemic hypersensitivity reactions such as drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported in patients taking sulfasalazine. Early manifestations of hypersensitivity, such as fever or lymphadenopathy, may be present even though rash is not evident. If such signs or symptoms are present, evaluate the patient immediately.

Discontinue AZULFIDINE if an alternative etiology for the signs or symptoms cannot be established. Other Severe Cutaneous Adverse Reactions Other severe cutaneous adverse reactions, including exfoliative dermatitis, Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP) have been reported in association with the use of sulfasalazine (see ADVERSE REACTIONS ). Severe cutaneous adverse reactions can be serious and are sometimes fatal.

Patients are at highest risk for these events early in therapy, with most events occurring within the first month of treatment. Discontinue AZULFIDINE at the first appearance of signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation.

🤒 Adverse Reactions ~2 min read

ADVERSE REACTIONS The most common adverse reactions associated with sulfasalazine are anorexia, headache, nausea, vomiting, gastric distress, and apparently reversible oligospermia. These occur in about one-third of the patients. Less frequent adverse reactions are skin rash, pruritus, urticaria, fever, Heinz body anemia, hemolytic anemia, and cyanosis, which may occur at a frequency of one in every thirty patients or less.

Experience suggests that with a daily dosage of 4 g or more, or total serum sulfapyridine levels above 50 µg/mL, the incidence of adverse reactions tends to increase. Although the listing which follows includes a few adverse reactions which have not been reported with this specific drug, the pharmacological similarities among the sulfonamides require that each of these reactions be considered when AZULFIDINE Tablets are administered. Less common or rare adverse reactions include: Blood dyscrasias: aplastic anemia, agranulocytosis, leukopenia, megaloblastic (macrocytic) anemia, purpura, thrombocytopenia, hypoprothrombinemia, methemoglobinemia, congenital neutropenia, and myelodysplastic syndrome.

Hypersensitivity reactions: erythema multiforme, epidermal necrolysis (SJS/TEN) with corneal damage, exfoliative dermatitis, DRESS, anaphylaxis, serum sickness syndrome, interstitial lung disease, pneumonitis with or without eosinophilia, vasculitis, fibrosing alveolitis, pleurisy/pleuritis, pericarditis with or without tamponade, allergic myocarditis, polyarteritis nodosa, lupus erythematosus-like syndrome, hepatitis and hepatic necrosis with or without immune complexes, fulminant hepatitis, sometimes leading to liver transplantation, parapsoriasis varioliformis acuta (Mucha-Haberman syndrome), rhabdomyolysis, photosensitization, arthralgia, periorbital edema, conjunctival and scleral injection, and alopecia.

Gastrointestinal reactions: hepatitis, hepatic failure, pancreatitis, bloody diarrhea, impaired folic acid absorption, impaired digoxin absorption, stomatitis, diarrhea, abdominal pains, and neutropenic enterocolitis. Central nervous system reactions: transverse myelitis, convulsions, meningitis, transient lesions of the posterior spinal column, cauda equina syndrome, Guillian-Barre syndrome, peripheral neuropathy, mental depression, vertigo, hearing loss, insomnia, ataxia, hallucinations, tinnitus, and drowsiness. Renal reactions: toxic nephrosis with oliguria and anuria, nephritis, nephrotic syndrome, urinary tract infections, hematuria, crystalluria, proteinuria, and hemolytic-uremic syndrome.

Other reactions: urine discoloration and skin discoloration. The sulfonamides bear certain chemical similarities to some goitrogens, diuretics (acetazolamide and the thiazides), and oral hypoglycemic agents. Goiter production, diuresis and hypoglycemia have occurred rarely in patients receiving sulfonamides.

Cross-sensitivity may exist with these agents. Rats appear to be especially susceptible to the goitrogenic effects of sulfonamides and long-term administration has produced thyroid malignancies in this species. Postmarketing Reports The following events have been identified during post-approval use of products which contain (or are metabolized to) mesalamine in clinical practice.

Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of seriousness, frequency of reporting, or potential causal connection to mesalamine: Blood dyscrasias: pseudomononucleosis Cardiac disorders: myocarditis Hepatobiliary disorders: reports of hepatotoxicity, including elevated liver function tests (SGOT/AST, SGPT/ALT, GGT, LDH, alkaline phosphatase, bilirubin), jaundice, cholestatic jaundice, cirrhosis, hepatitis cholestatic, cholestasis and possible hepatocellular damage including liver necrosis and liver failure.

Some of these cases were fatal. One case of Kawasaki-like syndrome, which included hepatic function ch…

🔄 Drug Interactions 20 words

Drug Interactions Reduced absorption of folic acid and digoxin have been reported when those agents were administered concomitantly with sulfasalazine.

🔄 Drug / Laboratory Test Interactions 108 words

Drug/Laboratory Test Interactions Several reports of possible interference with measurements, by liquid chromatography, of urinary normetanephrine causing a false-positive test result have been observed in patients exposed to sulfasalazine or its metabolite, mesalamine/mesalazine. Sulfasalazine or its metabolite, sulfapyridine, may interfere with ultraviolet absorbance, particularly at 340 nm, and may cause interference with some laboratory assays that use nicotinamide adenine dinucleotide [NAD(H)] or nicotinamide adenine dinucleotide phosphate [NADP(H)] to measure ultraviolet absorbance around that wavelength.

Examples of such assays may include alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase-muscle/brain (CK-MB), ammonia, thyroxine or glucose. Erroneous laboratory results may be observed in patients receiving higher than recommended dosages of sulfasalazine.

🤰 Pregnancy ~1 min read

Pregnancy There are no adequate and well-controlled studies of sulfasalazine in pregnant women. Reproduction studies have been performed in rats and rabbits at doses up to 6 times the human maintenance dose of 2 g/day based on body surface area and have revealed no evidence of impaired female fertility or harm to the fetus due to sulfasalazine. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

There have been case reports of neural tube defects (NTDs) in infants born to mothers who were exposed to sulfasalazine during pregnancy, but the role of sulfasalazine in these defects has not been established. However, oral sulfasalazine inhibits the absorption and metabolism of folic acid which may interfere with folic acid supplementation (see Drug Interactions) and diminish the effect of periconceptional folic acid supplementation that has been shown to decrease the risk of NTDs. A national survey evaluated the outcome of pregnancies associated with inflammatory bowel disease (IBD).

In a group of 186 women treated with sulfasalazine alone or sulfasalazine and concomitant steroid therapy, the incidence of fetal morbidity and mortality was comparable to that for 245 untreated IBD pregnancies as well as to pregnancies in the general population. 1 A study of 1,455 pregnancies associated with exposure to sulfonamides indicated that this group of drugs, including sulfasalazine, did not appear to be associated with fetal malformation. 2 A review of the medical literature covering 1,155 pregnancies in women with ulcerative colitis suggested that the outcome was similar to that expected in the general population.

3 No clinical studies have been performed to evaluate the effect of sulfasalazine on the growth development and functional maturation of children whose mothers received the drug during pregnancy

🧒 Pediatric Use 18 words

Pediatric Use Safety and effectiveness in pediatric patients below the age of 2 years have not been established.

🆘 Overdosage 167 words

OVERDOSAGE There is evidence that the incidence and severity of toxicity following overdosage are directly related to the total serum sulfapyridine concentration. Symptoms of overdosage may include nausea, vomiting, gastric distress, and abdominal pains. In more advanced cases, central nervous system symptoms such as drowsiness, convulsions, etc., may be observed.

Serum sulfapyridine concentrations may be used to monitor the progress of recovery from overdosage. There are no documented reports of deaths due to ingestion of large single doses of sulfasalazine. Doses of Azulfidine tablets of 16 g per day have been given to patients without mortality.

A single oral dose of 12 g/kg was not lethal to mice. Instructions for Overdosage Gastric lavage or emesis plus catharsis as indicated. Alkalinize urine.

If kidney function is normal, force fluids. If anuria is present, restrict fluids and salt, and treat appropriately. Catheterization of the ureters may be indicated for complete renal blockage by crystals.

The low molecular weight of sulfasalazine and its metabolites may facilitate their removal by dialysis.

🧬 Clinical Pharmacology ~3 min read

CLINICAL PHARMACOLOGY Pharmacodynamics The mode of action of sulfasalazine (SSZ) or its metabolites, 5-aminosalicylic acid (5-ASA) and sulfapyridine (SP), may be related to the anti-inflammatory and/or immunomodulatory properties that have been observed in animal and in vitro models, to its affinity for connective tissue, and/or to the relatively high concentration it reaches in serous fluids, the liver and intestinal walls, as demonstrated in autoradiographic studies in animals. In ulcerative colitis, clinical studies utilizing rectal administration of SSZ, SP, and 5-ASA have indicated that the major therapeutic action may reside in the 5-ASA moiety.

Pharmacokinetics In vivo studies have indicated that the absolute bioavailability of orally administered SSZ is less than 15% for parent drug. In the intestine, SSZ is metabolized by intestinal bacteria to SP and 5-ASA. Of the two species, SP is relatively well absorbed from the intestine and highly metabolized, while 5-ASA is much less well absorbed.

Absorption Following oral administration of 1 g of SSZ to 9 healthy males, less than 15% of a dose of SSZ is absorbed as parent drug. Detectable serum concentrations of SSZ have been found in healthy subjects within 90 minutes after the ingestion. Maximum concentrations of SSZ occur between 3 and 12 hours post-ingestion, with the mean peak concentration (6 µg/mL) occurring at 6 hours.

In comparison, peak plasma levels of both SP and 5-ASA occur approximately 10 hours after dosing. This longer time to peak is indicative of gastrointestinal transit to the lower intestine where bacteria mediated metabolism occurs. SP apparently is well absorbed from the colon with an estimated bioavailability of 60%.

In this same study, 5-ASA is much less well absorbed from the gastrointestinal tract with an estimated bioavailability of from 10 to 30%. Distribution Following intravenous injection, the calculated volume of distribution (Vdss) for SSZ was 7.5 ±

1.6L. SSZ is highly bound to albumin (>99.3%) while SP is only about 70% bound to albumin. Acetylsulfapyridine (AcSP), the principal metabolite of SP, is approximately 90% bound to plasma proteins.

Metabolism As mentioned above, SSZ is metabolized by intestinal bacteria to SP and 5-ASA. Approximately 15% of a dose of SSZ is absorbed as parent and is metabolized to some extent in the liver to the same two species. The observed plasma half-life for intravenous sulfasalazine is 7.6 ± 3.4 hours.

The primary route of metabolism of SP is via acetylation to form AcSP. The rate of metabolism of SP to AcSP is dependent upon acetylator phenotype. In fast acetylators, the mean plasma half-life of SP is 10.4 hours while in slow acetylators, it is 14.8 hours.

SP can also be metabolized to 5-hydroxy-sulfapyridine (SPOH) and N-acetyl-5-hydroxy-sulfapyridine. 5-ASA is primarily metabolized in both the liver and intestine to N-acetyl-5-aminosalicylic acid via a non-acetylation phenotype dependent route. Due to low plasma levels produced by 5-ASA after oral administration, reliable estimates of plasma half-life are not possible.

Excretion Absorbed SP and 5-ASA and their metabolites are primarily eliminated in the urine either as free metabolites or as glucuronide conjugates. The majority of 5-ASA stays within the colonic lumen and is excreted as 5-ASA and acetyl-5-ASA with the feces. The calculated clearance of SSZ following intravenous administration was 1 L/hr.

Renal clearance was estimated to account for 37% of total clearance. Special Populations Elderly Elderly patients with rheumatoid arthritis showed a prolonged plasma half-life for SSZ, SP, and their metabolites. The clinical impact of this is unknown.

Pediatric Small studies have been reported in the literature in children down to the age of 4 years with ulcerative colitis and inflammatory bowel disease. In these populations, relative to adults, the pharmacokinetics of SSZ and SP correlated poorly with either age or dose. Acetylator Status The metabolism…

📦 How Supplied / Storage and Handling 117 words

HOW SUPPLIED AZULFIDINE Tablets, 500 mg, are round, gold-colored, scored tablets, monogrammed "101" on one side and "KPh" on the other. They are available in the following package sizes: Bottle of 100 (with carton) NDC 0013-0101-10 Bottle of 100 NDC 0013-0101-01 Bottle of 300 (with carton) NDC 0013-0101-30 Bottle of 300 NDC 0013-0101-20 Store at 25° C (77° F); excursions permitted to 15–30° C (59–86° F) [see USP Controlled Room Temperature]. Sulfasalazine is also available as AZULFIDINE EN-tabs ® brand of sulfasalazine delayed release tablets, USP, 500 mg, in the following package sizes: Bottle of 100 (with carton) NDC 0013-0102-50 Bottle of 100 NDC 0013-0102-01 Bottle of 300 (with carton) NDC 0013-0102-60 Bottle of 300 NDC 0013-0102-20

📋 Description 46 words

DESCRIPTION AZULFIDINE Tablets contain sulfasalazine, 500 mg, for oral administration. Therapeutic Classification : Anti-inflammatory agent. Chemical Designation : 5-([p-(2-pyridylsulfamoyl)phenyl]azo) salicylic acid. Chemical Structure: Molecular Formula: C 18 H 14 N 4 O 5 S Inactive ingredients: magnesium stearate, povidone, silica (colloidal anhydrous), starch (pregelatinized). Chemical Structure

💬 Information for Patients 109 words

Information for Patients Patients should be informed of the possibility of adverse reactions and of the need for careful medical supervision. The occurrence of sore throat, fever, pallor, purpura, or jaundice may indicate a serious blood disorder. Should any of these occur, the patient should seek medical advice.

They should also be made aware that ulcerative colitis rarely remits completely, and that the risk of relapse can be reduced by continued administration of AZULFIDINE at a maintenance dosage. Patients should be instructed to take AZULFIDINE in evenly divided doses preferably after meals. Additionally, patients should be advised that sulfasalazine may produce an orange-yellow discoloration of the urine or skin.

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