Diflunisal

DEA NFLIS-Drug Category -> Analgesics

Pharmaceuticals -> Musculo-skeletal system -> Anti-inflammatory and antirheumatic products

Pharmaceuticals -> Listed in ZINC15

Practically insoluble (14.5 mg/L) at neutral or acidic pH.

7.11e-02 g/L

Breast Feeding; Lactation; Milk, Human; Analgesic Agents; Anti-inflammatory Agents, Nonsteroidal

FDA approved drugs -> Active ingredient

EMA approved medicines: Human medicine

FDA approved drugs -> Active ingredient

210-211

210 - 221 °C

3.3

3

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P203, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 42 reports by companies from 5 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

In the event of overdosage, the stomach should be emptied by inducing vomiting or by gastric lavage, and the patient carefully observed and given symptomatic and supportive treatment. Because of the high degree of protein binding, hemodialysis may not be effective. (L1712)

Diflunisal therapy is reported to be associated with a low rate of asymptomatic and transient serum aminotransferase elevations, which may resolve even with drug continuation. Marked aminotransferase elevations (>3 fold elevated) occur rarely. Clinically apparent liver injury with jaundice from diflunisal is uncommon; only case reports have been published. The clinical and histologic features of diflunisal hepatotoxicity, however, are distinct and resemble an immunoallergic hepatitis, which is quite different from the liver injury that occurs with aspirin or other salicylates (Case 1). The latency to onset ranges from 1 to 4 weeks and the pattern of enzyme elevations is typically cholestatic, but can also be mixed. Most patients have immunoallergic manifestations such as rash, fever and arthralgias; eosinophilia or atypical lymphocytosis are also common. A history of aspirin allergy has not been reported among cases with allergic reactions to diflunisal. Diflunisal is not a commonly used drug and is not mentioned in large case series on drug induced liver injury or acute liver failure.

The precise mechanism of the analgesic and anti-inflammatory actions of diflunisal is not known. Diflunisal is a prostaglandin synthetase inhibitor. In animals, prostaglandins sensitize afferent nerves and potentiate the action of bradykinin in inducing pain. Since prostaglandins are known to be among the mediators of pain and inflammation, the mode of action of diflunisal may be due to a decrease of prostaglandins in peripheral tissues.

Drug Induced Liver Injury Rank (DILIrank 2.0)

Diflunisal

vMost-DILI-concern

8

Warnings & precautions

DOI:10.1016/j.drudis.2016.02.015

N - Nervous system

QN - Nervous system

Diflunisal is a nonsteroidal drug with analgesic, anti-inflammatory and antipyretic properties. It is a peripherally-acting non-narcotic analgesic drug. Habituation, tolerance and addiction have not been reported. Diflunisal is a difluorophenyl derivative of salicylic acid. Chemically, diflunisal differs from aspirin (acetylsalicylic acid) in two respects. The first of these two is the presence of a difluorophenyl substituent at carbon 1. The second difference is the removal of the 0-acetyl group from the carbon 4 position. Diflunisal is not metabolized to salicylic acid, and the fluorine atoms are not displaced from the difluorophenyl ring structure.

The precise mechanism of the analgesic and anti-inflammatory actions of diflunisal is not known. Diflunisal is a prostaglandin synthetase inhibitor. In animals, prostaglandins sensitize afferent nerves and potentiate the action of bradykinin in inducing pain. Since prostaglandins are known to be among the mediators of pain and inflammation, the mode of action of diflunisal may be due to a decrease of prostaglandins in peripheral tissues.

Hepatic, primarily via glucuronide conjugation (90% of administered dose).

Hepatic, primarily via glucuronide conjugation (90% of administered dose). Route of Elimination: The drug is excreted in the urine as two soluble glucuronide conjugates accounting for about 90% of the administered dose. Little or no diflunisal is excreted in the feces. Half Life: 8 to 12 hours

7C546U4DEN

DIFLUNISAL

Mechanisms of Action [MoA] - Cyclooxygenase Inhibitors

Chemical Structure [CS] - Anti-Inflammatory Agents, Non-Steroidal

Established Pharmacologic Class [EPC] - Nonsteroidal Anti-inflammatory Drug

Diflunisal is a Nonsteroidal Anti-inflammatory Drug. The mechanism of action of diflunisal is as a Cyclooxygenase Inhibitor.

Anti-inflammatory agents that are non-steroidal in nature. In addition to anti-inflammatory actions, they have analgesic, antipyretic, and platelet-inhibitory actions. They act by blocking the synthesis of prostaglandins by inhibiting cyclooxygenase, which converts arachidonic acid to cyclic endoperoxides, precursors of prostaglandins. Inhibition of prostaglandin synthesis accounts for their analgesic, antipyretic, and platelet-inhibitory actions; other mechanisms may contribute to their anti-inflammatory effects.

Compounds or agents that combine with cyclooxygenase (PROSTAGLANDIN-ENDOPEROXIDE SYNTHASES) and thereby prevent its substrate-enzyme combination with arachidonic acid and the formation of eicosanoids, prostaglandins, and thromboxanes.

Rapidly and completely absorbed following oral administration, with a bioavailability of 80-90%. Peak plasma concentrations are achieved 2 - 3 hours following oral administration.

The drug is excreted in the urine as two soluble glucuronide conjugates accounting for about 90% of the administered dose. Little or no diflunisal is excreted in the feces.