Sulfasalazine
Sulfasalazine is an anti-inflammatory medicine used to treat ulcerative colitis and, in its delayed-release form, rheumatoid arthritis and juvenile rheumatoid arthritis.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 15 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Sulfasalazine: Patient Information Guide
A plain-language walkthrough of Sulfasalazine — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Sulfasalazine is approved for several inflammatory conditions depending on the product form.
- Treats mild to moderate ulcerative colitis (both tablet and delayed-release tablet forms)
- Used as add-on therapy in severe ulcerative colitis (both forms)
- Helps maintain remission and reduce flares of ulcerative colitis (both forms)
- Azulfidine EN-tabs and Sulfasalazine Delayed Release Tablets are approved for adults with rheumatoid arthritis who haven't responded well enough to NSAIDs or salicylates
- Azulfidine EN-tabs and Sulfasalazine Delayed Release Tablets are approved for children with polyarticular-course juvenile rheumatoid arthritis who haven't responded well enough to NSAIDs or salicylates
- The delayed-release tablet form is specifically useful for people with ulcerative colitis who experience significant stomach upset with uncoated tablets
⚙️How it works▾
Sulfasalazine works through anti-inflammatory and immune-modulating effects. Once swallowed, gut bacteria in the intestine break it down into two active components: 5-aminosalicylic acid (5-ASA) and sulfapyridine. In ulcerative colitis, 5-ASA appears to be the primary active piece, working directly on the intestinal lining to reduce inflammation. In rheumatoid arthritis, the exact contribution of each component is less clear, but the drug is thought to affect inflammatory pathways in joints and connective tissue.
💊How it's taken▾
Sulfasalazine is taken by mouth in divided doses throughout the day, generally multiple times daily. Both tablet forms are best taken after meals to reduce stomach upset. Delayed-release tablets must be swallowed whole — never crushed or chewed. Your prescriber will tailor your dose based on your condition, your response to treatment, and how well you tolerate the medicine; do not adjust the dose on your own.
- Tablet form: taken in evenly divided doses, with dosage intervals typically not exceeding eight hours
- Delayed-release tablet: taken in evenly divided doses, preferably after meals, tablets swallowed whole
- For rheumatoid arthritis, the delayed-release form does not work immediately — other pain medicines are usually continued until the effect becomes apparent
🤒Side effects — in detail▾
The most common side effects of sulfasalazine include:
- Nausea, vomiting, or stomach upset
- Loss of appetite
- Headache
- Abdominal pain
- Skin rash or itching
- Dizziness
- Orange-yellow discoloration of urine or skin (harmless but noticeable)
- Reduced sperm count in men (appears reversible after stopping the drug)
More serious reactions — including dangerous drops in blood cell counts, severe liver reactions, life-threatening skin blistering, and serious infections — require prompt medical attention. Call your doctor right away if you develop fever, sore throat, unusual bruising, yellowing skin or eyes, or a significant skin reaction.
⚠️Warnings & precautions▾
- Blood disorders: Sulfasalazine can cause serious, sometimes fatal drops in white blood cells (agranulocytosis), aplastic anemia, or other blood problems. Regular blood count monitoring is essential.
- Liver and kidney toxicity: Liver damage and kidney deterioration have been reported. Lab tests should be done regularly, and the drug should be stopped if kidney function worsens.
- Severe skin reactions: Life-threatening reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN), and DRESS (drug reaction with eosinophilia and systemic symptoms — a multi-organ hypersensitivity reaction) have occurred, most often in the first month. Stop the medicine immediately at the first sign of significant skin blistering, peeling, or widespread rash.
- Serious infections: Fatal sepsis and pneumonia have been reported, sometimes linked to low white blood cell counts. Tell your doctor about any signs of infection during treatment.
- Male fertility: Sulfasalazine can lower sperm count, but this appears to reverse after stopping the drug.
- Hypersensitivity: Severe allergic reactions affecting internal organs — including the heart, lungs, liver, and kidneys — have been reported. Seek immediate care if you develop fever, swollen lymph nodes, or organ-related symptoms.
🔀What it interacts with▾
Sulfasalazine can interact with certain medicines — tell your prescriber and pharmacist everything you take.
- Folic acid: Sulfasalazine can reduce how much folic acid your body absorbs, which may be important during pregnancy or if you are at risk for deficiency.
- Digoxin (used for heart conditions): Sulfasalazine can reduce digoxin absorption — monitoring may be needed.
- Methotrexate: When combined with sulfasalazine, the risk of gastrointestinal side effects — especially nausea — increases, though blood levels of both drugs were not significantly affected in studies.
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Do not take sulfasalazine if you are allergic to sulfonamide antibiotics, salicylates (like aspirin), or sulfasalazine itself
- Do not take if you have a blockage in your intestines or urinary tract
- Do not take if you have porphyria — sulfonamide medicines can trigger a dangerous acute attack
- Tell your doctor if you have liver disease, kidney disease, or a blood disorder
- Tell your doctor if you have a history of recurring or chronic infections, or if you take other medicines that lower immune function
- Older adults with rheumatoid arthritis may clear the drug more slowly — closer monitoring is advised
- The delayed-release tablet is approved for children 6 years and older for juvenile rheumatoid arthritis; both forms are used in children 6 and older for ulcerative colitis
- Talk to your doctor if you are pregnant, planning to become pregnant, or breastfeeding before starting this medicine
🚑If you take too much▾
Taking too much sulfasalazine may cause nausea, vomiting, stomach pain, and abdominal discomfort. In more severe overdose, central nervous system effects such as drowsiness or convulsions may occur. If you suspect an overdose, seek emergency medical care right away — treatment may include measures to clear the drug from your system and support kidney function.
📡Pharmacodynamics — effects in the body▾
Sulfasalazine and its breakdown products — 5-aminosalicylic acid (5-ASA) and sulfapyridine — have anti-inflammatory and immune-modulating properties. In ulcerative colitis, 5-ASA appears to be the primary active component, exerting its effects locally on the intestinal lining. The drug also has an affinity for connective tissue and reaches high concentrations in the liver and intestinal walls. Its precise mechanism in rheumatoid arthritis is not fully established.
🔬Pharmacokinetics — how your body processes it▾
Less than 15% of an oral dose of sulfasalazine is absorbed as the parent drug into the bloodstream. The bulk of it travels to the colon, where gut bacteria split it into sulfapyridine — which is well absorbed (about 60%) — and 5-ASA, which is only minimally absorbed (10–30%). Both breakdown products reach peak blood levels around 10 hours after a dose. The drug and its metabolites are mainly cleared through the urine. People who are "slow acetylators" (a genetic trait affecting how the liver processes sulfapyridine) break the drug down more slowly and may accumulate higher levels, which can increase the risk of side effects.
📦How to store it▾
Store at 25°C (77°F); excursions permitted to 15–30°C (59–86°F) .
📄 Written from Sulfasalazine’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
Supplements & herbs that interact with Sulfasalazine
39 supplements and herbal products have documented interactions with Sulfasalazine in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 28
- Minor · 10
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nutrient depletion considerations
Sulfasalazine has been associated with lower levels of 1 nutrient in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.
Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Sulfasalazine — the kind of thing our pharmacy team would talk through with you at the counter.
What is sulfasalazine actually used for? ▾
How long does it take to start working? ▾
What side effects should I expect, and which ones need a call to the doctor? ▾
Does it matter when I take it — with food, or at a certain time of day? ▾
Are there any medicines I should avoid while taking sulfasalazine? ▾
I've heard it can affect fertility — should I be concerned? ▾
Is Sulfasalazine available over the counter? ▾
When was Sulfasalazine first available? ▾
Who makes Sulfasalazine? ▾
💬 Answers drafted from Sulfasalazine’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Sulfasalazine comes
Sulfasalazine is available in 2 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Azulfidine Tablets are used to treat mild to moderate ulcerative colitis and as add-on therapy in severe ulcerative colitis
- Azulfidine Tablets are used to prolong remission between ulcerative colitis flares
- Sulfasalazine Tablets are used to treat mild to moderate ulcerative colitis and as add-on therapy in severe ulcerative colitis
- Sulfasalazine Tablets are used to prolong remission between ulcerative colitis flares
- Azulfidine Tablets are taken by mouth in evenly divided doses; dosage intervals should generally not exceed eight hours
- Sulfasalazine Tablets are taken by mouth in evenly divided doses; dosage intervals should generally not exceed eight hours
- If stomach upset occurs with Azulfidine Tablets, the dose may be reduced and then gradually increased over several days
- Follow your prescriber's instructions on dose — both brands are adjusted based on your individual response and tolerance
Delayed-release tablet
How this form is used
- Azulfidine EN-tabs are used to treat mild to moderate ulcerative colitis, as add-on therapy in severe ulcerative colitis, and to prolong remission — especially for patients who cannot tolerate uncoated tablets due to gastrointestinal side effects
- Azulfidine EN-tabs are used in adults with rheumatoid arthritis who have not responded adequately to NSAIDs or salicylates
- Azulfidine EN-tabs are used in children (6 years and older) with polyarticular-course juvenile rheumatoid arthritis who have not responded adequately to NSAIDs or salicylates
- Sulfasalazine Delayed Release Tablets are used for ulcerative colitis, rheumatoid arthritis, and juvenile rheumatoid arthritis under the same criteria as Azulfidine EN-tabs
- Azulfidine EN-tabs and Sulfasalazine Delayed Release Tablets should be swallowed whole — do not crush or chew them
- Both delayed-release products are preferably taken after meals in evenly divided doses
- In rheumatoid arthritis, Azulfidine EN-tabs do not produce an immediate response — concurrent pain relief with analgesics or NSAIDs is recommended until the effect becomes apparent
- Sulfasalazine Delayed Release Tablets dosing is adjusted individually based on response and tolerance — follow your prescriber's guidance
📊 Sulfasalazine across the U.S. market
How Sulfasalazine appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (9) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Sulfasalazine is used
A general measure of how commonly Sulfasalazine is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Sulfasalazine is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Sulfasalazine prescribed? Of the 1,596 medications we measure, Sulfasalazine ranks #511 by Medicaid prescriptions — more than 68% of them.
Utilization by Sulfasalazine product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
sulfasalazine 500 MG Oral Tablet Most dispensed
Summed across the 6 of 37 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 198232
sulfasalazine 500 MG Delayed Release Oral Tablet
Summed across the 2 of 12 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 313142
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Sulfasalazine, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 8 of 49 listed Sulfasalazine NDCs with Medicaid activity.
🔍 Compare Sulfasalazine products
A representative set of FDA-listed product records for Sulfasalazine — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Delayed-release tablet | ||||
| 500 mg | Oral | Greenstone LLC | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | Oral | Mylan Pharmaceuticals Inc. × 2 listings | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | Oral | Pfizer Laboratories Div Pfizer Inc × 2 listings | NDA | View NDC → |
| 500 mg | Oral | Sunrise Pharmaceutical, Inc. | ANDA | View NDC → |
| 💊Tablet | ||||
| 500 mg | Oral | A-S Medication Solutions × 5 listings | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | Oral | A-S Medication Solutions × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | Actavis Pharma, Inc. × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | American Health Packaging | ANDA | View NDC → |
| 500 mg | Oral | Aphena Pharma Solutions - Tennessee, LLC × 2 listings | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | Oral | Aphena Pharma Solutions - Tennessee, LLC | ANDA | View NDC → |
| 500 mg | Oral | Bryant Ranch Prepack × 3 listings | ANDA | View NDC → |
| 500 mg | Oral | Chartwell RX, LLC. × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | Greenstone LLC | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | — | Haupt Pharma Wuelfing GmbH. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 500 mg | Oral | Heritage Pharmaceuticals Inc. D/b/a Avet Pharmaceuticals Inc. × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | Mylan Pharmaceuticals Inc. × 2 listings | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | Oral | NuCare Pharmaceuticals,Inc. | ANDA | Find on DailyMed ↗ |
| 500 mg | Oral | Pfizer Laboratories Div Pfizer Inc × 2 listings | NDA | View NDC → |
| 500 mg | Oral | Remedyrepack Inc. × 3 listings | NDA AUTHORIZED GENERIC | View NDC → |
| 500 mg | Oral | Remedyrepack Inc. × 5 listings | ANDA | View NDC → |
| 500 mg | Oral | Rising Pharma Holdings, Inc. | ANDA | View NDC → |
| 500 mg | Oral | Sunrise Pharmaceutical, Inc. | ANDA | View NDC → |
| 500 mg | Oral | Teva Pharmaceuticals USA, Inc. | ANDA | View NDC → |
| 💊Bulk drug substance | ||||
| 1 kg/kg | — | Cambrex Charles City, Inc × 4 listings | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Cohance Lifesciences Limited | BULK INGREDIENT | View NDC → |
| 1 g/g | — | Letco Medical, Llc | BULK INGREDIENT | View NDC → |
| 1 g/g | — | Medisca Inc. | BULK INGREDIENT | View NDC → |
| 1 g/g | — | Spectrum Laboratory Products, Inc. | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Valens Molecules Private Limited | BULK INGREDIENT | View NDC → |
Showing 53 of 53 products — FDA National Drug Code Directory. See every product, package size and price: browse all 53 Sulfasalazine NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Sulfasalazine — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Sulfasalazine in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Sulfasalazine went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 9524 5 dose forms · 5 strengths
-
Dose form (SCDF) Delayed Release Oral Tablet RxCUI 376645In current FDA listingsClinical drug / strength (SCD) 500 MGRxCUI 313142 -
Dose form (SCDF) Enema RxCUI 373988No current FDA listingClinical drug / strength (SCD) 30 MG/MLRxCUI 104122 -
Dose form (SCDF) Oral Suspension RxCUI 373990No current FDA listingClinical drug / strength (SCD) 50 MG/MLRxCUI 104121 -
Dose form (SCDF) Oral Tablet RxCUI 373991In current FDA listingsClinical drug / strength (SCD) 500 MGRxCUI 198232 -
Dose form (SCDF) Rectal Suppository RxCUI 373989No current FDA listingClinical drug / strength (SCD) 500 MGRxCUI 250607
Look up RxCUI 9524 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Sulfasalazine is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Sulfasalazine belongs to the Aminosalicylate class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 15 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Greenstone LLC is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.