8 mins read

Overview: Diflunisal is a non-steroidal anti-inflammatory drug (NSAID), which is a medicine that is used to help treat pain, osteoarthritis, and rheumatoid arthritis. Diflunisal works to block specific substances in the body that cause pain, inflammation, and fever. Common side effects include nausea, upset stomach, and stomach pain. Before taking diflunisal, make sure to tell your healthcare provider about any health conditions or medications you are taking.

Uses

What is diflunisal used for?

Diflunisal is commonly used for the following conditions

  • Pain
  • Osteoarthritis, a condition that causes inflammation in the joints when cartilage (a type of tissue) breaks down
  • Rheumatoid arthritis, an autoimmune condition where your body attacks your joints

Diflunisal may also be used for other conditions as determined by your healthcare provider.

How does diflunisal work (mechanism of action)?

Diflunisal works by blocking certain substances in the body that cause pain, inflammation, and fever.

How is diflunisal supplied (dosage forms)?

Brands and other names

  • Dolobid

Dosage forms and strengths

  • 500 mg oral tablets

How should I store diflunisal?

Diflunisal should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.
 

Side Effects

What are the most common side effects of diflunisal?

The most common side effects of diflunisal are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Nausea
  • Upset stomach or stomach pain
  • Diarrhea
  • Rash
  • Headache

There may be other side effects of diflunisal that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of diflunisal?

While less common, the most serious side effects of diflunisal are described below, along with what to do if they happen.

Severe Allergic Reactions. Diflunisal can cause allergic reactions, including a specific type of allergic reaction called DRESS. DRESS stands for Drug Reaction with Eosinophilia and Systemic Symptoms. It is also sometimes called multiorgan hypersensitivity. This is a reaction that can affect multiple parts of the body, including your liver, kidneys, and heart. Stop taking the medicine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain
  • Dark colored urine
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Heart Attack and Stroke. Diflunisal can increase your risk of a heart attack or stroke that can lead to death. This risk is increased in people with existing heart disease and with longer use of diflunisal and higher doses. Do not take diflunisal if you have had a recent heart attack without talking to your healthcare provider. This could increase your risk of having another heart attack. Get emergency help if you have any of the following symptoms of a heart attack or stroke.

  • Chest pain or pressure
  • Fast or abnormal heartbeat
  • Trouble breathing
  • Pain in your back, jaw, throat, or arm
  • Sweating, upset stomach, vomiting, or dizziness
  • Sudden weakness on one side of your body
  • Sudden and severe headache
  • Slurred speech or trouble understanding speech

Increased Blood Pressure (Hypertension). Diflunisal may increase your blood pressure or make it worse if you have a history of high blood pressure. Call your healthcare provider if your blood pressure increases while taking this medicine.

If you measure your blood pressure and the top number (systolic) is 180 mm Hg or higher or the bottom number (diastolic) is 120 mm Hg or higher, get medical attention right away. Increases in blood pressure may not be noticeable, but look out for and tell your healthcare provider right away if you have any of the following symptoms of severely high blood pressure.

  • Sudden severe headache
  • Chest pain
  • Dizziness or confusion
  • Trouble breathing
  • Nausea or vomiting
  • Blurry or other changes to vision
  • Anxiety
  • Buzzing in the ears
  • Nosebleed
  • Feeling of skipped heartbeats

Fluid Retention (Edema) and Heart Failure. Diflunisal can cause fluid retention, also called edema which can lead to heart failure. Fluid retention can also cause serious issues in people with heart failure. Call your healthcare provider right away if you have any of the following symptoms. 

  • Chest pain
  • Irregular heartbeat
  • Shortness of breath
  • Stretched or shiny skin
  • Swollen body parts, such as the belly or ankles
  • Unusually fast weight gain
  • Unusual tiredness

Stomach Bleeding. Diflunisal can increase your risk of bleeding, ulcers, and tears (perforation) in your gut. The risk is higher if you have a history of stomach ulcers, bleeding problems, take higher doses of diclofenac or take it for longer than directed, have poor health, are of older age, have liver disease, smoke, drink alcohol, or take certain other medicines. Stop taking diflunisal and get emergency help if you have any of the following symptoms.

  • Vomit blood
  • Black or tarry poop
  • Stomach pain that does not go away
  • Upset stomach
  • Feel faint

Kidney Damage. Kidney damage can happen when taking diflunisal. Call your healthcare provider right away if you have any of the following symptoms of kidney damage.

  • Reduced need to pee
  • Swelling in your feet, ankles, or legs
  • Weakness or unusual tiredness
  • Difficulty catching your breath or chest pain/pressure
  • Confusion
  • Nausea
  • Seizures

Severe Skin Reactions. Diflunisal can cause severe skin reactions, called Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN), that can lead to death if not treated. If you develop a rash, stop diflunisal and call your healthcare provider right away. Get emergency help if you have any of the following symptoms of SJS or TEN.

  • Painful red or purple skin that looks burned and peels off
  • Flat red rash or blisters on your skin, mouth, nose, and genitals
  • Red, painful, watery eyes

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking diflunisal. Call your healthcare provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Anemia. Diflunisal may cause anemia, which is when you have low levels of red blood cells. Tell your healthcare provider if you have any of the following symptoms of anemia.

  • Unusual weakness or tiredness
  • Cold hands and feet
  • Fast or abnormal heartbeat
  • Pale or yellowish skin 
  • Dizziness, lightheadedness, or feeling like you are about to pass out
  • Shortness of breath

Eye Problems. Diflunisal may cause eye problems. Call your healthcare provider if you have any changes in your vision.

Reye’s Syndrome. Diflunisal may cause a rare but serious condition called Reye’s syndrome, which can lead to swelling in the liver and the brain. Reye’s syndrome can occur at any age, but most commonly affects children. Call your healthcare right away if you have any of the following symptoms.

  • Personality changes
  • Confusion
  • Hallucinations
  • Weakness or tiredness
  • Seizures
  • Loss of consciousness

Warnings & Precautions

Who should not use diflunisal?

Allergies to Ingredients. People who are allergic to any of the following should not take diflunisal.

  • Diflunisal 
  • Dolobid
  • Aspirin or any other medicine known as a non-steroidal anti-inflammatory (NSAID)
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific diflunisal products they stock.

Heart Surgery. Do not take diflunisal right before or after a heart surgery called coronary artery bypass graft (CABG). Taking diflunisal during this time can increase your risk of heart attack or stroke.

What should I know about diflunisal before using it?

People who are 65 and older can be at greater risk for some side effects from diflunisal. Talk to your healthcare provider about your risks if you are in this age group.

Do not chew, cut, or crush diflunisal tablets.

Do not take diflunisal unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share diflunisal with other people, even if they have the same condition as you. It may harm them.

Keep diflunisal out of the reach of children.

What should I tell my healthcare provider before using diflunisal?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if diflunisal is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Liver or kidney problems
  • High blood pressure
  • Asthma
  • Heart conditions including heart failure or a recent heart attack
  • Anemia

Other Medicines and Supplements. Diflunisal may interact with other medicines and supplements. Before taking diflunisal, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Smoking. Tell your healthcare provider if you smoke. Smoking while taking diflunisal can increase the risk of stomach bleeding. 

Pregnancy. Do not take diflunisal 20 weeks or later in pregnancy without talking to your healthcare provider. Taking diflunisal during this time may cause harm to an unborn baby and complications during delivery. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take diflunisal while you are pregnant or trying to get pregnant.

Breastfeeding. Diflunisal passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should stop breastfeeding or stop diflunisal.

Interactions

Does diflunisal interact with foods or drinks?

There are no known interactions between diflunisal and foods or drinks.

It is unknown if drinking alcohol will affect diflunisal, but both diflunisal and alcohol can increase your risk of bleeding. It is best to limit the amount of alcohol you drink.

Does diflunisal interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking diflunisal.

  • An angiotensin-converting enzyme (ACE) inhibitor, such as enalapril or lisinopril, which is a medicine for high blood pressure, heart failure, and certain kidney problems
  • An angiotensin II receptor blocker (ARB), such as losartan or valsartan, which is a medicine for high blood pressure, heart failure, and other heart conditions
  • Acetaminophen (Tylenol), which is a medicine used for pain or fever
  • An antacid
  • Aspirin, which is in many prescription and OTC products, including those for pain, swelling, and fever
  • Cyclosporine (Gengraf, Neoral, Sandimmune, and others), which is a medicine that suppresses your immune system
  • A diuretic, also called a water pill, which is a medicine used to reduce edema (fluid retention) and blood pressure
  • Lithium, which is a medicine for certain mental health conditions
  • Methotrexate (Trexall and others), which is a medicine commonly used for rheumatoid arthritis or certain types of cancer
  • A nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen, naproxen, sulindac, indomethacin, and others, which is in many prescription and OTC products for pain, swelling, and fever
  • A blood thinner, such as warfarin, which is a medicine used to treat or prevent blood clots

This may not be a complete list of medicines that can interact with diflunisal. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much diflunisal?

If you or someone else has used too much diflunisal, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of diflunisal?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.