Diflunisal is a non-specific prostaglandin synthesis inhibitor available in 250 and 500mg tablets with analgesic, anti-pyretic Diflunisal is a non-specific prostaglandin synthesis inhibitor available in 250 and 500mg tablets with analgesic,(pain reliever) anti-pyretic (fever reducing) and anti-inflammatory medical properties. Since it is a peripheral (eextremitiy) prostaglandin inhibitor, there is no habituation, tolerance, or addiction., which is important medically since its analgesic properties are equivalent in 1000mg to 600 mg acetaminophen and 60mg codeine( i.e. Tylenol #4) without the narcotic effects.

Chemically, “diflunisal" (as the generic name might suggest) is derivative of salicylic acid as “di-fluorophenyl acid. The compound differs from aspirin (acetylsalicylic acid) in that it is not metabolized (broken down)to salicylic acid . The drug is absorbed well reducing GI (stomach , intestine) side effects, with peak blood levels in 2-3 hours and is excreted mostly in the urine with minimal concentration in human milk and only minimal passage through the placental barrier. It should not used during the third trimester of pregnancy and only with extreme caution in the first two trimesters with significant consideration of the benefits versus the risks of possible teratogenic results.

For significant pain, the initial doses of two 500mg tablets provides fast relief , with quicker onset of action and shorter time to peak analgesia with a significant number of patients not having to re-medicate with a following dose even up to 12 hours after the initial doses,. Usual dosing regiment of two times a day ( dolo-BID, BID the Latin nomenclature for twice a day).

The effectiveness in rheumatoid arthritis with doses of 500-1000mg daily is equivalent in relief to 2-4 grams (2000 to 4000 mg) of aspirin daily usually without the adverse effects of GI distress, tinnitus(ringing in the ears)and less blood loss in the stool(fecal blood) The effectiveness both for acute and long term management of RA is demonstrated by the clinical improvement with ease of pain with range of motion, improving the signs and symptom of the disease process. For those patients requiring gold salts for RA, Diflunisal be used in combination for additional relief of symptoms. Similar response is found with those patients suffering from osteoarthritis (DJD, degenerative joint disease) of the hip and knee with reduced pain of range of motion.

Diflunisal may also be used for acute gout attacks due to its uricosuric effect (ability to reduce elevated uric acid) dosed at 500mg to 1000 mg in two dose intervals. The drug will inhibit platelet function and effect bleeding time when taken in 1000 mg twice daily doses, but at lower dosage of 250 mg twice daily for 8 days no effect was noted and only a mild light effect at 500mg twice daily. The bleeding effects are easily reversible. Diabetic blood sugars are not seemingly affected by the medication.

Though it produces anti-pyretic effects, it is usually reserved clinically for mild to moderate pain, osteoarthritis, and rheumatoid arthritis. It should be avoided in those patients who have experienced asthmatic attacks, urticaria(severe rashes), or rhinitis (severe nasal symptoms) from aspirin or any other non-steroidal anti-inflammatory medications.

As with all the non-steroidal anti-inflammatory medications, adverse reactions may occur. The most frequent with Diflunisal have been of the GI system including nausea, vomiting, dyspepsia,(stomach ache symptoms) diarrhea, constipating, and flatulence(bloating, gas0. Other symptoms of insomnia, dizziness, skin rash, (usually mild) flushing, head aches, fatigue, tiredness, sweating, and dry mucous membranes of the nasal and oral passages, nervousness and edema may occur.

Drug interactions with Diflunisal are similar to the other non-steroidal due to similar pharmacology. The medication and aspirin or NSAIDs should be avoided due to displacement from protein binding sites rendering the medication less effective. Oral anticoagulants will have prolonged prothrombin time and bleeding. The thiazide diuretics will have increased plasma levels Antacids will reduce plasma levels of the Diflunisal with reduced effects., Plasma levels of acetaminophen may be elevated.

REFERENCES

PDR, Physicians Desk Reference, 59th Edition 2005

Drug.com, DIFUNISAL - DOLOBID

I have found Diflunisal beneficial in the adult population with moderate pain, when the anticipated drowsiness of the codeine derivatives were contraindicated due to work or daily requirements of living when mental and/or physical acuity were essential. I felt it was as effective as codeine, without the stupor or drowsiness when the patient had no contraindications or allergies to the NSAIDs.

ADDITIONAL REFERENCES

Drugs.com

National Institutes of Health

MedlinePlus

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