Medically reviewed by Drugs.com. Last updated on Sep 12, 2022.
Cardiovascular Thrombotic EventsNonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. Diflunisal tablets are contraindicated in the setting of coronary artery bypass graft (CABG) surgery Gastrointestinal RiskNSAIDs cause an increased risk of serious gastrointestinal adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events can occur at any time during use and without warning symptoms. Elderly patients are at greater risk for serious gastrointestinal events .
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Analgesic
Pharmacologic Class: NSAID
Chemical Class: Salicylate, Non-Aspirin
Uses for diflunisal
Diflunisal is a nonsteroidal anti-inflammatory drug (NSAID) used to treat mild to moderate pain, and helps to relieve symptoms of arthritis (eg, osteoarthritis and rheumatoid arthritis), including inflammation, swelling, stiffness, and joint pain. Diflunisal does not cure arthritis and will help you only as long as you continue to take it.
Diflunisal is available only with your doctor's prescription.
Before using diflunisal
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For diflunisal, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to diflunisal or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of diflunisal in children younger than 12 years of age. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatrics-specific problems that would limit the usefulness of diflunisal in the elderly. However, elderly patients are more likely to have age-related kidney or stomach problems, which may require caution and an adjustment in the dose for patients receiving diflunisal.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking diflunisal, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using diflunisal with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using diflunisal with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Amtolmetin Guacil
- Bismuth Subsalicylate
- Choline Magnesium Trisalicylate
- Choline Salicylate
- Dabigatran Etexilate
- Ethacrynic Acid
- Flufenamic Acid
- Magnesium Salicylate
- Mefenamic Acid
- Niflumic Acid
- Nimesulide Beta Cyclodextrin
- Pentosan Polysulfate Sodium
- Phenyl Salicylate
- Potassium Citrate
- Protein C
- Salicylic Acid
- Sodium Salicylate
- Tenofovir Disoproxil Fumarate
- Tiaprofenic Acid
- Tolfenamic Acid
- Trolamine Salicylate
Using diflunisal with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Azilsartan Medoxomil
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of diflunisal. Make sure you tell your doctor if you have any other medical problems, especially:
- Anemia or
- Asthma or
- Bleeding problems or
- Blood clots or
- Edema (fluid retention or body swelling) or
- Heart attack, history of or
- Heart disease (eg, congestive heart failure) or
- Hypertension (high blood pressure) or
- Kidney disease or
- Liver disease (eg, hepatitis) or
- Stomach or intestinal ulcers or bleeding, history of or
- Stroke, history of—Use with caution. Diflunisal may make these conditions worse.
- Aspirin-sensitive asthma or
- Aspirin sensitivity, history of or
- Kidney disease, severe—Should not be used in patients with these conditions.
- Heart surgery (eg, coronary artery bypass graft [CABG] surgery)—Should not be used to relieve pain right before or after the surgery.
Proper use of diflunisal
For safe and effective use of diflunisal, do not take more of it, do not take it more often, and do not take it for a longer time than ordered by your doctor. Taking too much of diflunisal may increase the chance of unwanted effects, especially in elderly patients.
Diflunisal should come with a Medication Guide. It is very important that you read and understand this information. Be sure to ask your doctor about anything you do not understand.
Swallow the tablet whole. Do not crush or chew it.
The dose of diflunisal will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of diflunisal. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For mild to moderate pain:
- Adults and children 12 years of age and older—At first, 1000 milligrams (mg) followed by 500 mg every 12 hours. Your doctor may adjust your dose as needed and tolerated. However, the dose is usually not more than 1500 mg a day.
- Children younger than 12 years of age—Use and dose must be determined by your doctor.
- For osteoarthritis and rheumatoid arthritis:
- Adults and children 12 years of age and older—500 to 1000 milligrams (mg) 2 times a day. Your doctor may adjust your dose as needed and tolerated. However, the dose usually is not more than 1500 mg once a day.
- Children younger than 12 years of age—Use and dose must be determined by your doctor.
- For mild to moderate pain:
If you miss a dose of diflunisal, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Precautions while using diflunisal
It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood and urine tests may be needed to check for unwanted effects.
Using diflunisal during the later part of pregnancy can harm your unborn baby. If you think you have become pregnant while using the medicine, tell your doctor right away.
Diflunisal may raise your risk of having a heart attack or stroke. This is more likely in people who already have heart disease or in people who use diflunisal for a long time.
Diflunisal may cause bleeding in your stomach or intestines. These problems can happen without warning signs. This is more likely if you have had a stomach ulcer in the past, if you smoke or drink alcohol regularly, if you are over 60 years old, if you are in poor health, or if you are using certain other medicines (eg, steroids or a blood thinner).
Check with your doctor right away if you have bloody urine, a decrease in frequency or amount of urine, an increase in blood pressure, increased thirst, loss of appetite, lower back or side pain, nausea, swelling of the face, fingers, or lower legs, trouble breathing, unusual tiredness or weakness, vomiting, or weight gain. These could be symptoms of a serious kidney problem.
Diflunisal may cause a serious allergic reaction called anaphylaxis, which can be life-threatening and requires immediate medical attention. It may occur more often in patients who are allergic to aspirin or to any of the nonsteroidal anti-inflammatory drugs. Call your doctor right away if you have a rash, itching, trouble breathing or swallowing, or any swelling of your hands, face, or mouth while you are using diflunisal.
Diflunisal can cause a rare but serious condition called Reye's syndrome. It occurs mostly in children and teenagers, but can affect someone at any age. Do not give diflunisal to anyone who has chicken pox or symptoms of a virus or the flu, unless your doctor has told you to. If a child has behavior changes along with nausea and vomiting while using diflunisal, .
Serious skin reactions, including exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS) can occur during treatment with diflunisal. Check with your doctor right away if you have black, tarry stools, blistering, peeling, or loosening of the skin, chest pain, chills, cough, diarrhea, fever, itching, joint or muscle pain, painful or difficult urination, red irritated eyes, red skin lesions, sore throat, sores, ulcers, or white spots in the mouth or on the lips, swollen glands, unusual bleeding or bruising, or unusual tiredness or weakness.
Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.
Possible warning signs of some serious side effects that can occur during treatment with diflunisal may include swelling of the face, fingers, feet, and/or lower legs, severe stomach pain, black, tarry stools, vomiting of blood or material that looks like coffee grounds, unusual weight gain, yellow skin or eyes, decreased urination, bleeding or bruising, or skin rash. Also, signs of serious heart problems could occur including chest pain or tightness, fast or irregular heartbeat, unusual flushing or warmth of skin, weakness, or slurring of speech. Check with your doctor immediately if you notice any of these warning signs.
Check with your doctor immediately if blurred vision, difficulty in reading, or any other change in vision occurs during or after your treatment. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).
Before having any kind of surgery or medical tests, tell your doctor that you are using diflunisal. It may be necessary for you to stop treatment for a while, or to change to a different NSAID before your procedure.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Diflunisal side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Stomach cramps or pain
- Back or leg pains
- bleeding gums
- blistering, peeling, loosening of skin
- bloody or black, tarry stools
- bloody or cloudy urine
- blurred or loss of vision
- burning feeling in chest or stomach
- burning while urinating
- clay-colored stools
- cough or hoarseness
- cracks in the skin
- dark-colored urine
- difficult or painful urination
- difficulty breathing
- difficulty swallowing
- disturbed color perception
- double vision
- facial swelling
- fast heartbeat
- feeling of warmth
- fever with or without chills
- flu-like symptoms
- general body swelling
- greatly decreased frequency of urination or amount of urine
- halos around lights
- hives, itching, skin rash
- increased blood pressure
- increased thirst
- joint or muscle pain
- large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs
- light-colored stools
- loss of appetite
- loss of heat from the body
- lower back or side pain
- muscle aches, pains, or weakness
- nausea or vomiting
- night blindness
- noisy breathing
- overbright appearance of lights
- pale skin
- pinpoint red spots on skin
- puffiness or swelling of the eyelids or around the eyes, face, lips or tongue
- red, irritated eyes
- redness of the face, neck, arms and occasionally, upper chest
- red skin lesions, often with a purple center
- red, swollen skin
- scaly skin
- severe or continuing stomach pain
- sores, ulcers, or white spots in mouth or on lips
- sore throat
- stomach upset, tenderness
- swelling of the face, fingers, feet or lower legs
- swollen lymph nodes
- tightness in chest
- trouble breathing
- tunnel vision
- unpleasant breath odor
- unusual bleeding or bruising
- unusual tiredness or weakness
- upper right stomach pain
- vomiting of blood or material that looks like coffee grounds
- weight gain
- yellow eyes or skin
Symptoms of overdose
- Change in consciousness
- confusion about identity, place, and time
- continuing ringing or buzzing or other unexplained noise in ears
- decreased awareness or responsiveness
- deep or fast breathing with dizziness
- fast, pounding, or irregular heartbeat or pulse
- hearing loss
- loss of consciousness
- numbness of feet, hands, and around mouth
- severe sleepiness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Acid or sour stomach
- stomach discomfort or upset
- Bloated, full feeling
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- dry mucous membranes
- excess air or gas in stomach or intestines
- feeling of constant movement of self or surroundings
- feeling sad or empty
- increased sensitivity of skin to sunlight
- lack or loss of strength
- loss of interest or pleasure
- mood or mental changes
- passing gas
- seeing, hearing, or feeling things that are not there
- sensation of spinning
- severe sunburn
- swelling or inflammation of the mouth
- trouble concentrating
- trouble sleeping
- unable to sleep
- weight loss
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
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- Drug class: Nonsteroidal anti-inflammatory drugs
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