- Type of Drug: Nonsteroidal anti-inflammatory drug (NSAID).
- Prescribed for: Rheumatoid arthritis; osteoarthritis; mild to moderate pain.
Diflunisal is chemically related to Aspirin but is considered to be a nonsteroidal anti-inflammatory drug (NSAID), similar to the others that are used to relieve pain and inflammation. We do not know exactly how NSAIDs work, but part of their action may be caused by an ability to inhibit the body’s production of a hormone called prostaglandin and to inhibit the action of other body chemicals, including cyclo-oxygenase, lipoxygenase, leukotrienes, lysosomal enzymes, and a host of other factors. Diflunisal is absorbed into the bloodstream fairly rapidly. Pain relief comes within 1 hour after taking the first dose, but the drug’s anti-inflammatory effect takes a lot longer (several days to 2 weeks) to become apparent and may take several months to reach its maximum.
Cautions and Warnings
People who are allergic to Diflunisal (or any other NSAID) and those with a history of asthma attacks brought on by another NSAID, by Iodides, or by Aspirin should not take Diflunisal.
This medicine can cause gastrointestinal (GI) bleeding, ulcers, and perforation. This can occur at any time with or without warning in people who take chronic Diflunisal treatment. People with a history of active GI bleeding should be cautious about taking any NSAID. Minor stomach upset, gas, or distress is common during the first few days of treatment with Diflunisal. People who develop bleeding or ulcers and continue their NSAID treatment should be aware of the possibility of developing more serious drug toxicity.
Diflunisal can affect platelets and blood clotting at high doses and should be avoided by people with clotting problems and those taking Warfarin.
People with heart problems who use Diflunisal may find that their arms and legs or feet become swollen.
Diflunisal can cause severe toxic side effects to the kidney. Report any unusual side effects to your doctor, who may need to periodically test your kidney function.
Diflunisal can make you unusually sensitive to the effects of the sun.
Because Diflunisal is related to Aspirin, it should be used with caution in children and adolescents because of the possibility of Reye’s syndrome.
Possible Side Effects
- Most common: diarrhea, nausea, vomiting, constipation, stomach gas, stomach upset or irritation, and loss of appetite.
- Less common: stomach ulcers, GI bleeding, hepatitis, gallbladder attacks, painful urination, poor kidney function, kidney inflammation, blood and protein in the urine, dizziness, fainting, nervousness, depression, hallucinations, confusion, disorientation, tingling in the hands or feet, light-headedness, itching, increased sweating, dry nose and mouth, heart palpitations, chest pain, difficulty breathing, and muscle cramps.
- Rare: severe allergic reactions, including, closing of the throat, fever and chills, changes in liver function, jaundice (yellowing of the skin or eyes), and kidney failure. People who experience such effects must be promptly treated in a hospital emergency room or doctor’s office.
NSAIDs have caused severe skin reactions; if this happens to you, see your doctor immediately.
• Diflunisal can increase the effects of oral anticoagulant (blood-thinning) drugs such as Warfarin. You may take this combination, but your doctor may have to reduce your anticoagulant dose to take this effect into account.
• Diflunisal may increase Acetaminophen blood levels by as much as 50 percent. This can be a problem for people with liver disease.
• Diflunisal increases the blood levels and effects of Thiazide diuretics.
• Combining Diflunisal with Indomethacin can cause GI bleeding, which can be fatal. Do not take this combination.
Take Diflunisal with food or a magnesium/aluminum antacid if it upsets your stomach.
500 mg to 1000 mg to start, then 250 mg to 500 mg every 8 to 12 hours. Do not take more than 1500 mg a day. Take each dose with a full glass of water and don’t lie down for 15 to 30 minutes after you take the medicine. Do not crush or chew Diflunisal tablets.
People have died from Diflunisal overdoses. The most common overdose signs are drowsiness, nausea, vomiting, diarrhea, abdominal pain, rapid breathing, rapid heartbeat, increased sweating, ringing or buzzing in the ears, confusion, disorientation, stupor, and coma.
Take the victim to a hospital emergency room at once. ALWAYS bring the medicine bottle with you.
Diflunisal can make you drowsy and/or tired: Be careful When driving or operating hazardous equipment.
Do not take any nonprescription products with Acetaminophen or Aspirin while taking Diflunisal; also, avoid alcoholic beverages.
Contact your doctor if you develop skin rash, itching, visual disturbances, weight gain, breathing difficulty, fluid retention, hallucinations, black stools, or persistent headache. Call your doctor if you develop any unusual side effects or if side effects become intolerable.
If you forget to take a dose of Diflunisal, take it as soon as you remember. If you take several Diflunisal doses a day and it is within 4 hours of your next dose, skip the one you forgot and continue with your regular schedule. If you take Diflunisal once a day, and it is within 8 hours of your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose.
Diflunisal may cross into the fetal blood circulation. It has not been found to cause birth defects, but may affect a developing fetal heart during the last 3 months of pregnancy. Pregnant women and those who might become pregnant should not take Diflunisal without their doctors’ approval; pregnant women should be particularly cautious about using this drug during the last 3 months of their pregnancy. When the drug is considered essential by your doctor, its potential benefits must be carefully weighed against its risks.
Diflunisal passes into breast milk- There is a possibility that a nursing mother taking Diflunisal could affect her baby’s heart or cardiovascular system. Nursing mothers who must take this drug should bottle-feed their babies.
Older adults may be more susceptible to Diflunisal side effects, especially ulcer disease.