Diflunisal (Oral)

Belonging to the class of drugs known as non-steroidal anti-inflammatory (NSAIDs), Diflunisal can help to relieve many of the symptoms associated with osteoarthritis and rheumatoid arthritis.


Diflunisal is a medication which is primarily used to relieve pain, stiffness, and swelling in the joints, often caused by various types of arthritis. Many patients who are afflicted by arthritis would have a good deal of difficulty with mobility and flexibility in their daily lives if not for the relief of symptoms provided by this medication.

It is a medication taken orally, usually with a full glass of water at meal time or afterward, so as to prevent the onset of an upset stomach. The mechanism which makes dilunisal effective is that it lowers the level of prostaglandins in the body, which are substances responsible for triggering fever, pain, and inflammation in the body.

There is a specific enzyme called cyclooxygenases which cause prostaglandins to be produced, and diflunisal blocks the production of this enzyme, which in turn leads to the reduction of the prostaglandins that cause trouble and make people suffer. Since the body's level of prostaglandins are reduced after ingestion of diflunisal, the patient notices the results as less pain, less stiffness, and less swelling of joints around the body.

Condition Treated

Osteoarthritis, rheumatoid arthritis, moderate pains

Type Of Medicine

Non-steroidal anti-inflammatory

Side Effects

Along with the intended benefits of diflunisal, some patients will experience side effects caused by the medication which vary in severity and frequency from person to person. Some patients may experience no side effects at all, while others exhibit symptoms from taking the drug which are severe enough to require medical attention for relief. When you are first beginning a program of treatment with diflunisal, it's a good idea to observe your body's reaction to the medication for the first few weeks, so that you can gauge whether or not your body is tolerating the medication, and whether or not there will be any adverse reactions.

The first reaction to look for is an allergic reaction, because the symptoms associated with this condition can grow to be severe enough as to be temporarily debilitating or even life-threatening. The signs of an allergic reaction are as follows: the immediate appearance of hives or rashes, a sensation of tightness in the chest, which might be accompanied by difficulty breathing, pronounced swelling in the facial area or of the tongue, lips, or mouth.

If any of these symptoms appear in the immediate aftermath of taking diflunisal, you should seek emergency medical attention right away, before these side effects worsen. There is a class of fairly serious side effects which you should be on the alert for, because these may also require medical attention:

  • Stomach or abdominal pain
  • Feet or hands becoming swollen
  • Sudden and unexplained weight gain
  • Changes in vision or blurred vision
  • Ringing in the years or difficulty hearing
  • Extreme mood changes
  • Disorientation or confusion
  • Hallucinations
  • Irregular or pounding heartbeat
  • Headaches which become severe and/or persistent
  • The sensation of feeling faint, as though you are about to pass out
  • Sore throat or difficulty swallowing
  • Severe heartburn
  • Changes in urine flow
  • Unusual bleeding
  • Unexplained stiffness in the neck
  • Signs of liver disease such as dark-colored urine, extreme fatigue or tiredness, unabated nausea or vomiting, strong pains in the abdomen or stomach, and a yellowish tinge to the skin, or around the eyes
  • Signs of a heart attack or stroke - pains which originate in the chest area, then emanate to the shoulders, or to the area of the jaw; a sudden weakness, tingling sensation, or feeling of numbness on one side of the body; speech which becomes slurred and possibly unintelligible; sudden shortness of breath
  • Signs of stomach bleeding - tarry stools, blood in the stools, vomiting or coughing up material which has the appearance of coffee grounds
  • Signs of anemia (low red blood cell count) - difficulty with concentration or focus, rapid rate of heartbeat, feeling of light-headedness, sudden pale look to the skin, as though the blood has drained out of it
  • Extreme reaction on the skin surfaces around the body - burning around the eyes; reddish or purple-colored rashes appearing in various locations; peeling or blistering skin; fever and/or sore throat
  • Diarrhea, constipation, or persistent flatulence.


The appropriate dosage for any given patient of diflunisal will depend on several different factors, all of which will be taken into account by your doctor. The first factor will be exactly which medical condition you're being treated for, e.g. moderate pain, some type of arthritis, etc. Then too, your current medical condition will be considered, for instance if you have some previously existing disease already ongoing in your system.

Your age will also be a factor, because younger patients as well as older patients would not need as much medication in order for it to be effective. In the case of geriatric patients, medication often stays in the system longer than it would for younger people, simply because it isn't eliminated as quickly, so it can be effective for a longer period of time.

The precise dosage which your doctor prescribed for you will also depend on the strength of the tablets being prescribed, as well as the dosage schedule and frequency during the program of treatment. The dosages listed below should be considered a standard dosage, and are not intended to be understood as a one-size-fits-all kind of recommendation.

For an adult being treated for mild to moderate pain, an initial dosage of 1000 mg is a commonly prescribed dosage, with a reinforcing dosage of 500 mg, spaced apart by 12-hour intervals. In some cases the dosage intervals can be spaced together more closely, for example 8 hours or perhaps 6 hours when the patient's discomfort is more severe. Lower or somewhat higher dosages may be recommended based on the patient's tolerance to the medication, the severity of the pain, your age, or possibly even your body weight.

In such instances, the prescribed dosage might be 500 mg, followed up with 250 mg reinforcements every 8 to 12 hours. It is not advisable to exceed 1500 mg in a 24-hour period, and the tablets should never be chewed or crushed into a beverage, but should be swallowed whole instead.

If you should miss a dosage of diflunisal, it is permissible to take the missed dosage as soon as you think of it, unless you don't think of it until close to the time of the next scheduled dosage. In this situation, it's much better to skip the missed dosage and just take the next regularly scheduled one. You should never double up on dosages just to get back on schedule, because that runs the risk of overdosing on diflunisal.


There is a potential for diflunisal to have interactions with other drugs which may impart adverse effects to the patient. In order to avoid the potential for drug interactions, it's a good idea for a patient considering treatment with diflunisal to prepare a full list of all medications you are currently taking, including other prescription medications, vitamins, herbal supplements, and over-the-counter drugs, in addition to the dosages for each one of these.

Once your doctor has a chance to review this list, he/she will be able to make a determination whether any of the drugs on the list might have a negative reaction with diflunisal. You can also use this list when it's necessary for you to visit some kind of healthcare facility or emergency care unit where your primary doctor will not be present. Any doctor in residence at one of these facilities will be able to review your medication list, and safely prescribe treatment for whatever condition brought you to the clinic.

When you are considering a program of treatment with diflunisal, you should avoid drinking alcohol, because it can significantly raise the risk of some kind of stomach bleeding, which could result in a serious medical condition. You should also avoid taking any other kinds of nonsteroidal anti-inflammatory drugs or aspirin while you are being treated with diflunisal.

Before using over-the-counter drugs such as medicines for colds, pain relief, or allergies, make sure to consult with your doctor, because a great many of these medications contain aspirin or the same kinds of ingredients which make up diflunisal. The risk with this is that you might be doubling or tripling the medication you are taking, because diflunisal has a very similar composition to these over-the-counter drugs.

If you currently have any medications in the house which include naproxen, ketoprofen, ibuprofen, or aspirin, you should consult your doctor before continuing to use any of these other medicines.

Before using any kind of antacids, consult with your doctor, because some of them can make it much more difficult for your body to effectively absorb diflunisal. Your doctor may recommend a specific type of antacid which does not conflict with the absorptive capabilities of diflunisal.

Another class of medications that you should consult with your doctor about is if you are taking any kind of antidepressants, because these can make you much more susceptible to bruising and bleeding than you would be otherwise. Medications in this class include the following:

  • Citalopram
  • Fluoxetine
  • Sertraline
  • Fluvoxamine
  • Paroxetine
  • Trazodone.
  • Escitalopram

Some other medicines which are known to interact with diflunisal, and which you should consult with your doctor about are the following:

  • Any kind of blood pressure medications
  • Diuretics (water pills)
  • Steroids, e.g. prednisone
  • Cyclosporine
  • Lithium
  • Acetaminophen
  • Methotrexate
  • Coumadin
  • Warfarin
  • Jantoven.


Some warnings or precautions are associated with taking diflunisal, and these should be carefully observed, because there's a potential for serious medical conditions to develop which would be worse than the condition they are treating. If your doctor has prescribed diflunisal in your case, he/she has made a determination that the benefits imparted by the medication are much greater than the risks associated with taking it. However, it is impossible to predict how any specific patient will react to taking any kind of medication, so it's very important to monitor a patient's condition in the first days and weeks of treatment with a new medication.

Make sure to tell your doctor if you know that you are allergic to diflunisal, to aspirin, or to any other kinds of salicylates or nonsteroidal anti-inflammatory drugs, such as ibuprofen, naproxen, or celecoxib. In addition, it's a good idea to point out your doctor if you have any other allergies whatsoever, even if they are not associated with medications. For instance, you may have an allergy to certain fabrics, pets, preservatives, or foods, and your doctor should be made aware of this fact. There are certain inactive ingredients in diflunisal which may trigger these allergies, even if they are normally triggered by medications.

When your consulting with your doctor about being prescribed some kind of medication for treatment of your arthritic or pain condition, you will most likely be asked to provide a complete review of your medical history, so that any potential risks can be identified and avoided. During this consultation, make sure to point out all of the following:

  • Asthma or any kind of respiratory issue, especially when triggered by taking aspirin or nonsteroidal anti-inflammatory drugs
  • Diabetes of either type I or type II
  • Ulcers or other kinds of stomach disorders
  • Intestinal issues
  • Problems with your esophagus
  • Heart disease, heart attack, or stroke
  • High blood pressure
  • Fluid retention
  • Blood disorders such as anemia
  • Problems with blood clotting
  • Nasal polyps
  • Kidney problems
  • Dehydration.

If you are expecting to undergo some type of surgery, even if it is oral surgery, make sure that your doctor and/or your dentist are aware that you are taking diflunisal. They may want to recommend that you temporarily discontinue your program of treatment with diflunisal for a period before and after the scheduled surgery.

It is possible for diflunisal to make you dizzy or drowsy, so you should avoid operating a motor vehicle or any other kind of machinery after taking this medication, so that you don't cause a danger to yourself and to others. You should be aware that taking alcohol or marijuana are likely to deepen the effects of the diflunisal medication, and can make you even dizzier or more drowsy than you might otherwise have been, creating an even more dangerous situation.

It's possible for diflunisal to either start stomach bleeding or to worsen stomach bleeding that you may have already had, so you should be alert to signs of any kind of stomach bleeding. These will include blood in your stool or tarry stools that are much deeper color than normal. Alcohol and smoking can exacerbate any situation with stomach bleeding, so this is another good reason to avoid ingesting both of those substances when taking diflunisal.

Elderly patients are often more susceptible to the side effects of diflunisal, especially the intestinal or stomach bleeding aspects, as well as the impact on the kidneys. It is not advisable for children aged 12 years and under to be taking diflunisal, and since this medication is a close cousin of aspirin, children of this age should not take diflunisal when they have influenza, chickenpox or any other illness which is undiagnosed.

Women who are pregnant or thinking of becoming pregnant should not take diflunisal, because there is a risk that it will inhibit the possibility of becoming pregnant, or that it will increase the likelihood of a com/health/miscarriage/">miscarriage. Diflunisal is known to have an impact on an unborn fetus, so at the very least, this medication should not be taken during the first or last trimesters of pregnancy because of the potential for harm to the baby, as well as for the potential of causing delivery problems.

It is also known that diflunisal can be passed to a nursing infant through breast milk, so breast-feeding is not at all advisable when a patient is taking diflunisal. There is a potential for nursing infants to develop growth issues such as being underweight or under-sized when breast-feeding from a mother taking diflunisal. If you are serious about wanting to breast-feed your infant, you should discuss the situation with your doctor, so he/she can recommend a medication other than diflunisal for your pain management. This may allow you to manage pain and breast-feed safely at the same time.


Diflunisal should be stored in a location where it cannot be accessed by pets or curious children, and this generally means that it should be placed somewhere so high that it cannot be recached, even with the aid of standing on furniture. For the same reason, your medication should not be kept in a weekly pill reminder, because these containers are seldom equipped with any kind of safety mechanism which locks the container against unwanted access. If a child should somehow gain access to your diflunisal medication, you should contact your doctor or local Poison Control Center for instructions.

To ensure that diflunisal is not accessed by household members unintentionally, make sure not to flush unused medication down the toilet or down the sink. Instead, ask your doctor or pharmacist about how to safely dispose of the medication, so no one else can find it and accidentally ingest it. The FDA maintains a website for the safe disposal of medicines which you can consult, if you have no other good source of advice on proper disposal methods.

Do not share or give your medication to a friend or relative, even if they are experiencing the same kind of pain that you are, and you think your medication might help them. Your doctor has prescribed this medication for you based on your specific circumstances and your specific medical condition. It may be dangerous for anyone else to ingest the dosage you have been prescribed, and there is no way of knowing how another person may react to the medication - it is even possible for someone else to have an allergic reaction to the drug, which could become a serious issue.

Storage of diflunisal should be in a place which receives no direct lighting, and which is not subject to any kinds of extremes of temperature, for instance freezing, severe cold, or high heat. Excessive moisture is also a bad condition for this medication, because it can degrade the effective properties of the drug. Bathroom medicine cabinets are always a poor choice of location for medications, because of the potential for high heat and humidity during bathing times.


Diflunisal belongs to the class of drugs known as non-steroidal anti-inflammatory drugs, and it works by reducing the inflammation in the body which causes pain in the joints and elsewhere. It is commonly used to treat osteoarthritis, rheumatoid arthritis, and non-arthritic joint pain for this reason. By blocking the production of enzymes in the body which help generate prostaglandins, diflunisal can significantly reduce many of the symptoms associated with arthritis, such as swelling, stiffness, and moderate to severe joint pain.

When taking diflunisal, it is necessary to be very cautious about taking some ordinary over-the-counter drugs such as aspirin and allergy medications, because some of them contain many of the same ingredients as diflunisal. This being the case, the amount of medication ingested can be doubled or even tripled if diflunisal is taken in conjunction with any of these similar medications, and that can potentially lead to an overdose of medication.

The dosage of diflunisal which will be necessary to manage pain for any given patient might be very different for a number of reasons, for instance the condition being treated, the patient's medical condition, and the person's age.

For the first few days and weeks after beginning a treatment program with diflunisal, a patient's reaction to the drug should be carefully monitored, in case any adverse side effects should appear. If this should happen, the family doctor may want to alter the dosage of diflunisal being prescribed, or he/she may want to change the medication entirely to something more tolerable for the patient. Very few patients experience severe side effects when taking diflunisal, but since some of these can be dangersous, e.g. stomach bleeding, all patient reactions should be carefully gauged when taking this medication, especially when the time frame is a more prolonged one.