Diflunisal
Diflunisal is a nonsteroidal anti-inflammatory drug (NSAID) used to treat mild to moderate pain, osteoarthritis, and 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 6 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 →
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Diflunisal carries two serious FDA boxed warnings that every patient should know about.
Heart risk: NSAIDs like diflunisal increase the risk of heart attack and stroke, which can be fatal. This risk can appear even with short-term use and may grow the longer you take the drug. People with existing heart disease or risk factors are at the highest absolute risk, but even those without known heart disease are affected. Diflunisal must not be used right before or after coronary artery bypass graft (CABG) heart surgery.
Stomach and intestinal risk: Diflunisal can cause serious bleeding, ulcers, or holes (perforation) in the stomach or intestines — and these can happen at any time without warning, even in people with no previous stomach problems. Older adults are especially vulnerable. If you notice black or bloody stools, severe stomach pain, or vomit that looks like coffee grounds, seek emergency care immediately.
📖 Diflunisal: Patient Information Guide
A plain-language walkthrough of Diflunisal — 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▾
Diflunisal is an NSAID approved for several pain and inflammatory conditions across its supported products.
- Mild to moderate pain (short-term or long-term) — supported by both Dolobid and diflunisal tablets
- Osteoarthritis — supported by both Dolobid and diflunisal tablets
- Rheumatoid arthritis — supported by both Dolobid and diflunisal tablets
⚙️How it works▾
Diflunisal inhibits prostaglandin synthetase — an enzyme the body uses to make prostaglandins, which are chemical messengers that promote pain, swelling, and inflammation. With fewer prostaglandins in tissues, pain signals are dampened and inflammation is reduced. Diflunisal acts primarily at the peripheral (tissue) level rather than in the brain, which is why it relieves pain without causing the sedation or dependence associated with opioid pain medicines.
Diflunisal is chemically related to aspirin but is not converted to salicylic acid in the body, and its fluorine atoms remain intact — this accounts for its longer duration of action and different pharmacokinetic behavior compared to aspirin.
💊How it's taken▾
Diflunisal tablets are taken by mouth. For pain, a higher starting (loading) dose is commonly used to get the drug working faster, followed by a lower maintenance dose taken every 8 to 12 hours. For osteoarthritis or rheumatoid arthritis, the drug is generally taken twice daily. Because diflunisal builds up in the body in a nonlinear way — meaning small dose increases can lead to disproportionately larger drug levels — your prescriber will tailor your dose carefully.
- Swallow tablets whole; do not crush or chew
- Allow 2 to 3 days to assess any change in dose if a loading dose was not used
- Always use the lowest effective dose for the shortest necessary duration
- Follow your prescriber's specific instructions — do not adjust your dose on your own
🤒Side effects — in detail▾
The most common side effects of diflunisal involve the stomach and digestive system, but other effects are also possible.
- Nausea, vomiting, stomach pain, or diarrhea
- Constipation or gas (flatulence)
- Headache
- Dizziness
- Rash
- Fatigue or tiredness
- Sleepiness or trouble sleeping
- Ringing in the ears (tinnitus)
Serious reactions — including stomach bleeding, ulcers, severe skin reactions (such as Stevens-Johnson syndrome), liver problems, kidney impairment, and serious allergic reactions — are less common but require immediate medical attention. Stop taking diflunisal and contact your doctor or seek emergency care if you experience any of these.
⚠️Warnings & precautions▾
- Heart attack and stroke risk: Diflunisal and all NSAIDs increase the risk of serious, sometimes fatal, cardiovascular events — including heart attack and stroke. Risk may appear early in treatment and grows with higher doses and longer use. Diflunisal is contraindicated around the time of CABG heart surgery and should be avoided or used with extreme caution in people with recent heart attacks or severe heart failure.
- Gastrointestinal bleeding and ulcers: Serious stomach or intestinal bleeding, ulcers, and perforation can happen at any time, often without warning. Risk is highest in older adults, people with a prior history of ulcers, and those also taking blood thinners, steroids, or aspirin.
- Kidney damage: Long-term use or use in people with reduced kidney function, heart failure, liver disease, or dehydration can lead to significant kidney damage, including kidney failure. Diflunisal is not recommended in advanced kidney disease.
- Serious skin reactions: Rare but potentially fatal skin conditions — including Stevens-Johnson syndrome and toxic epidermal necrolysis — can occur. Stop the drug immediately at the first sign of a rash or skin reaction.
- Pregnancy risk: Avoid diflunisal from about 20 weeks of pregnancy onward; it can harm fetal kidney development and cause other serious fetal complications. It is contraindicated from about 30 weeks gestation.
- Severe allergic/hypersensitivity reactions: Anaphylaxis and a multi-organ hypersensitivity syndrome have been reported. Seek emergency care immediately if signs of a severe reaction occur.
🔀What it interacts with▾
Diflunisal can interact with several common medications, altering their effectiveness or increasing the risk of serious side effects.
- ACE inhibitors and ARBs (blood pressure medicines) — diflunisal may blunt their antihypertensive effect and increase risk of kidney failure when combined
- Acetaminophen — diflunisal raises acetaminophen blood levels significantly, which can increase liver toxicity risk; use together only with close monitoring
- Warfarin and other oral anticoagulants — diflunisal may prolong clotting time; blood-clotting levels (prothrombin time) must be monitored closely, and the combination raises GI bleeding risk
- Aspirin — combined use is generally not recommended; it increases the risk of adverse effects and reduces diflunisal levels slightly
- Diuretics (water pills) — diflunisal can reduce diuretic effectiveness and raise kidney failure risk; hydrochlorothiazide levels may increase
- Lithium — diflunisal raises lithium blood levels, which can lead to lithium toxicity
- Methotrexate — NSAIDs may enhance methotrexate toxicity; use with caution
- Indomethacin — do not use together; this combination has caused fatal gastrointestinal hemorrhage
- Cyclosporine — combined use may increase cyclosporine-related kidney toxicity
- Antacids — regular antacid use can reduce diflunisal blood levels
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 diflunisal if you have ever had asthma, hives, or a serious allergic reaction after taking aspirin or any other NSAID
- Do not use diflunisal if you are allergic to diflunisal itself or any inactive ingredients in the tablet
- Diflunisal must not be taken around the time of coronary artery bypass graft (CABG) surgery
- Tell your doctor if you have heart disease, high blood pressure, or risk factors for heart disease — your cardiovascular risk must be weighed carefully
- Tell your doctor if you have a history of stomach ulcers, GI bleeding, liver disease, or kidney problems
- Patients with advanced kidney disease should not use diflunisal
- Older adults are at higher risk for serious GI and cardiovascular events and require careful monitoring
- Pregnant women should avoid diflunisal from about 20 weeks of pregnancy; it is particularly dangerous from 30 weeks onward
- Diflunisal passes into breast milk — discuss the risks with your doctor before breastfeeding
- Tell your doctor about all medications you take, especially blood thinners, lithium, diuretics, ACE inhibitors, and other NSAIDs
🚑If you take too much▾
Taking too much diflunisal can be dangerous and has been associated with deaths. Warning signs of overdose include drowsiness, nausea, vomiting, diarrhea, rapid breathing, fast heart rate, sweating, ringing in the ears, confusion, stupor, and in severe cases, loss of consciousness or heart and breathing problems. If an overdose is suspected, call Poison Control (1-800-222-1222) or seek emergency medical care immediately — do not wait for symptoms to worsen.
📡Pharmacodynamics — effects in the body▾
Diflunisal relieves pain and reduces inflammation by decreasing prostaglandin levels in peripheral tissues — the same chemicals responsible for sensitizing pain receptors and amplifying the pain response. It begins producing meaningful pain relief within about 1 hour of a dose, with peak effect typically at 2 to 3 hours. Because of its long duration of action, pain relief lasts longer than many comparable analgesics. Diflunisal does not appear to act significantly on the central nervous system, as very little of the drug crosses into the cerebrospinal fluid.
🔬Pharmacokinetics — how your body processes it▾
Diflunisal is rapidly and completely absorbed after oral dosing, with peak blood levels reached in 2 to 3 hours. It has a plasma half-life of 8 to 12 hours — roughly 3 to 4 times longer than aspirin — which allows for twice-daily dosing in most patients. More than 99% of the drug is bound to proteins in the blood, and it is eliminated primarily through the urine as metabolites. Because diflunisal follows nonlinear (concentration-dependent) pharmacokinetics, small increases in dose can produce disproportionately larger increases in drug levels, especially with repeated dosing — which is why a loading dose is often used and dose changes require careful monitoring over several days.
📦How to store it▾
Store at 20° to 25°C (68° to 77°F) . Dispense in a tight container (USP).
📄 Written from Diflunisal’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 Diflunisal
52 supplements and herbal products have documented interactions with Diflunisal in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 5
- Moderate · 35
- Minor · 12
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
Diflunisal 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 Diflunisal — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is diflunisal used for? ▾
How should I take diflunisal tablets? ▾
What side effects should I watch out for? ▾
I take a blood thinner — is it safe for me to use diflunisal? ▾
Can I take diflunisal if I'm pregnant or breastfeeding? ▾
I've heard NSAIDs can affect the heart — should I be worried? ▾
Is Diflunisal available over the counter? ▾
When was Diflunisal first available? ▾
Who makes Diflunisal? ▾
💬 Answers drafted from Diflunisal’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 Diflunisal comes
Diflunisal is available in 1 form. 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
- Dolobid is indicated for mild to moderate pain, osteoarthritis, and rheumatoid arthritis
- Diflunisal tablets are indicated for mild to moderate pain, osteoarthritis, and rheumatoid arthritis
- Tablets must be swallowed whole — Dolobid and diflunisal tablets should not be crushed or chewed
- Dolobid and diflunisal tablets are taken by mouth, typically every 8 to 12 hours depending on condition and individual response
- For arthritis, Dolobid and diflunisal tablets are generally taken in two divided doses daily
- Use the lowest effective dose for the shortest duration; your prescriber will adjust the dose based on your response
📊 Diflunisal across the U.S. market
How Diflunisal 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.
Also listed with the FDA, not a patient dose form: Powder (3) — 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 Diflunisal is used
A general measure of how commonly Diflunisal 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 Diflunisal 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 Diflunisal prescribed? Of the 1,596 medications we measure, Diflunisal ranks #804 by Medicaid prescriptions — more than 50% of them.
Utilization by Diflunisal 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.
diflunisal 250 MG Oral Tablet Most dispensed
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197602
diflunisal 375 MG Oral Tablet
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 249400
diflunisal 500 MG Oral Tablet
Summed across the 4 of 31 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197603
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 Diflunisal, 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 6 of 33 listed Diflunisal NDCs with Medicaid activity.
🔍 Compare Diflunisal products
A representative set of FDA-listed product records for Diflunisal — 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 |
|---|---|---|---|---|
| 💊Tablet | ||||
| 500 mg | Oral | Chartwell RX, LLC × 2 listings | ANDA | View NDC → |
| 25 kg/25 kg | — | Cohance Lifesciences Limited | BULK INGREDIENT FOR HUMAN PRESCRIPTION COMPOUNDING | View NDC → |
| 500 mg | Oral | Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. × 3 listings | ANDA | View NDC → |
| 250 mg | Oral | INA Pharmaceutics Inc | ANDA | View NDC → |
| 375 mg | Oral | INA Pharmaceutics Inc | ANDA | View NDC → |
| 500 mg | Oral | Rising Pharmaceuticals Inc. | ANDA | View NDC → |
| 500 mg | Oral | Teva Pharmaceuticals USA, Inc. × 3 listings | ANDA | View NDC → |
| 500 mg | Oral | Zydus Lifesciences Limited × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | Zydus Pharmaceuticals (USA) Inc. × 2 listings | ANDA | View NDC → |
| 💊Bulk drug substance | ||||
| 1 kg/kg | — | Aarti Pharmalabs Limited | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Apicore Pharmaceuticals Private Limited | BULK INGREDIENT | View NDC → |
| 15 kg/15 kg | — | Emcure Pharmaceuticals Limited | BULK INGREDIENT | View NDC → |
Showing 19 of 19 products — FDA National Drug Code Directory. See every product, package size and price: browse all 19 Diflunisal 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 Diflunisal — 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 Diflunisal 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 Diflunisal 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 3393 1 dose form · 3 strengths
-
Dose form (SCDF) Oral Tablet RxCUI 371828In current FDA listings
Look up RxCUI 3393 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 Diflunisal 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
Diflunisal belongs to the Nonsteroidal Anti-inflammatory Drug 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 6 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. Teva Pharmaceuticals USA, Inc. 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.