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Clinical data | |
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Trade names | Dolobid |
Other names | MK647 |
AHFS/Drugs.com | Monograph |
MedlinePlus | a684037 |
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Routes of administration | By mouth |
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Pharmacokinetic data | |
Bioavailability | 80-90% |
Protein binding | >99% |
Metabolism | Liver |
Elimination half-life | 8 to 12 hours |
Excretion | Kidney |
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ECHA InfoCard | 100.040.925 |
Chemical and physical data | |
Formula | C13H8F2O3 |
Molar mass | 250.201 g·mol−1 |
3D model (JSmol) | |
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Diflunisal is a salicylic acid derivative with analgesic and anti-inflammatory activity. [2] It was developed by Merck Sharp & Dohme in 1971, after showing promise in a research project studying more potent chemical analogs of aspirin. [3] It was first sold under the brand name Dolobid, by Merck & Co., but generic versions are widely available. It is classed as a nonsteroidal anti-inflammatory drug (NSAID) and is available in 250 mg and 500 mg tablets.
Diflunisal is indicated for acute or long-term use for symptomatic treatment of mild to moderate pain, osteoarthritis, and rheumatoid arthritis. [1]
Both diflunisal [4] [5] and several of its analogues [6] have been shown to be inhibitors of transthyretin-related hereditary amyloidosis, a disease which currently has few treatment options. Phase I trials have shown the drug to be well tolerated, [7] with a small Phase II trial (double-blind, placebo-controlled, 130 patients for 2 years) in 2013 showing a reduced rate of disease progression and preserved quality of life. [8]
In October 2020, the US Food and Drug Administration (FDA) required the drug label to be updated for all nonsteroidal anti-inflammatory medications to describe the risk of kidney problems in unborn babies that result in low amniotic fluid. [9] [10] They recommend avoiding NSAIDs in pregnant women at 20 weeks or later in pregnancy. [9] [10]
Diflunisal acts by inhibiting the production of prostaglandins, [11] hormones which are involved in inflammation and pain. Diflunisal also has an antipyretic effect, but this is not a recommended use of the drug. [12]
It has been found to inhibit p300 and CREB-binding protein (CBP), which are epigenetic regulators that control the levels of proteins that cause inflammation or are involved in cell growth. [13]
Though diflunisal has an onset time of 1 hour, and maximum analgesia at 2 to 3 hours, the plasma levels of diflunisal will not be steady until repeated doses are taken. [12] The long plasma half-life is a distinctive feature of diflunisal in comparison to similar drugs. To increase the rate at which the diflunisal plasma levels become steady, a loading dose is usually used. It is primarily used to treat symptoms of arthritis, [14] and for acute pain following oral surgery, especially removal of wisdom teeth. [15]
In April 2025, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Attrogy, intended for the treatment of hereditary transthyretin-mediated amyloidosis in adults with stage 1 or stage 2 polyneuropathy. [16] The applicant for this medicinal product is Purpose Pharma International AB. [16]
Diflunisal may have some antibacterial activity in vitro against Francisella tularensis live vaccine strain (LVS). [17]