Medications and Drugs
Pharmacy Author: Annette Gbemudu-Ogbru, PharmD, MBA
Medical and Pharmacy Editor: Jay W. Marks, MD
GENERIC NAME: diflunisal
BRAND NAME: Dolobid (This brand is no longer available in the U.S.)
DRUG CLASS AND MECHANISM: Diflunisal is a
nonsteroidal antiinflammatory drug
(NSAID) that is effective in treating fever, pain, and inflammation in the body.
Other members of this class include ibuprofen (Motrin), indomethacin (Indocin),
nabumetone (Relafen), naproxen (Anaprox, Naprosyn, Aleve) and several others.
These drugs are used for the management of mild to moderate pain, fever, and
inflammation. They work by reducing the levels of prostaglandins, chemicals that
are responsible for pain, fever, and inflammation. Diflunisal blocks the enzymes
that make prostaglandins (cyclooxygenases), resulting in lower concentrations of
prostaglandins. As a consequence, inflammation, pain and fever are reduced.
Diflunisal was approved by the FDA in April 1982.
PRESCRIPTION: Yes
GENERIC AVAILABLE: Yes
PREPARATIONS: Tablets: 250 and 500 mg.
STORAGE: Diflunisal tablets should be stored in well-sealed containers at a
temperature less than 40 C (104 F), preferably at 15–30 C (59-86 F).
PRESCRIBED FOR: Diflunisal is used for the treatment of mild to moderate
pain, osteoarthritis and rheumatoid arthritis.
DOSING: For mild to moderate pain, an initial dose of 1000 mg followed by 500
mg every 12 hours is recommended for most patients. For osteoarthritis and
rheumatoid arthritis, the suggested dosage range is 250 mg to 500 mg twice
daily.
DRUG INTERACTIONS: Concomitant use of NSAIDs with
angiotensin-converting
enzyme (ACE) inhibitors such as enalapril (Vasotec) or angiotensin II receptor
antagonists such as irbesartan (Avapro) may reduce the blood pressure response
to the antihypertensive agent since prostaglandins are important in controlling
blood pressure.
Diflunisal may increase the blood levels of lithium (Eskalith) by reducing
the excretion of lithium by the kidneys. Increased levels of lithium may lead to
lithium toxicity.
When diflunisal is used in combination with methotrexate
(Rheumatrex, Trexall), the blood levels of
methotrexate may increase, presumably because the elimination from the body is
reduced. This may lead to more methotrexate related side effects.
Individuals taking oral blood thinners or anticoagulants, for example,
warfarin, (Coumadin) should avoid diflunisal because diflunisal also thins the
blood, and excessive blood thinning may lead to bleeding.
PREGNANCY: There are no adequate studies with diflunisal in
pregnant women.
Diflunisal should be used only if the potential benefit justifies the potential
risk.
NURSING MOTHERS: Diflunisal is excreted in
human milk and has a potential for
adverse events to infants.
SIDE EFFECTS: Most patients benefit from diflunisal and other NSAIDs with few
side effects. However, serious side effects can occur and generally tend to be
seen at higher doses. Therefore, it is often desirable to use the lowest
effective dose to minimize side effects. The most common side effects of
diflunisal involve the gastrointestinal system. It can cause ulcerations,
abdominal burning, pain, cramping, nausea, gastritis, and even serious
gastrointestinal bleeding and
liver toxicity. Sometimes, stomach ulceration and
bleeding can occur without any abdominal pain.
Black tarry stools, weakness, and
dizziness upon standing may be the only signs of internal bleeding. Rash, kidney
impairment, ringing in the ears, and lightheadedness also are seen.
Reference: FDA Prescribing Information
Last Editorial Review: 10/8/2009
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

- ibuprofen, Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, etc. - Explains the medication ibuprofen (Advil, Motrin, Nuprin, Medipren) a drug used for the management of mild to moderate pain, fever, and inflammation. Article includes descriptions, uses, drug interactions, and side effects.
- Rheumatoid Arthritis - Learn more about rheumatoid arthritis, an autoimmune disease that causes chronic joint inflammation, which has symptoms that include stiffness, fever, muscle and joint aches, loss of appetite, and fatigue. Treatment of rheumatoid arthritis incorporates the use of first-line drugs (aspirin and corticosteroids for pain and inflammation) and second-line drugs (methotrexate and hydroxychloroquine to prevent joint destruction and promote remission).
- Nonsteroidal Antiinflammatory Drugs (NSAIDs) - Describes Nonsteroidal Antiinflammatory Drugs (NSAIDs), which are medications used primarily to treat inflammation, mild to moderate pain, and fever.
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