Diflunisal

Diflunisal (MK-647) is a salicylate derivative with nonsteroidal anti-inflammatory and uricosuric properties, which is used alone as an analgesic and in rheumatoid arthritis patients. The mechanism of action of diflunisal is as a Cyclooxygenase (COX) Inhibitor.

Research Areas >> Inflammation/Immunology

COX

Administration of increasing doses of Diflunisal to rats shows that the effect of the dose on the pharmacokinetics of Diflunisal is quite complicated. The plasma concentrations of Diflunisal decline exponentially with time, albeit with a half-life that increases with increasing dose. The CLP is reduced considerably when the dose increases from 3 to 10 mg/kg and then remains relatively constant over the dose range of 10 to 60 mg/kg. Diflunisal has been shown to be highly bound to rat plasma protein and dependent on concentration. The fraction of unbound Diflunisal is increased about 10-fold over the concentration range of 5 to 300 μg/mL[1]. Diflunisal exhibits activity after oral administration with potency about 25 times greater than that of aspirin, about 3 times that of glafenine and twice that of zomepirac[2].

Rats[1] For the study of dose dependency, Diflunisal is administered by i.a. injection in doses of 3, 10, 30 and 60 mg/kg (1.5, 5, 15 and 30 mg/mL dosing solution in 0.1 M NaHCO3). The infusion studies consist of a bolus injection of Diflunisal followed immediately by a 7-hr infusion at a constant rate. Seven groups of rats are included in the infusion studies. The loading doses used are 2, 3, 5, 10, 25, 50 and 80 mg/kg and their corresponding infusion rates are 3, 4.5, 9, 18, 36, 72 and 144 μg/min (0.576 mL/hr of seven different dosing solutions: 0.31, 0.47, 0.94, 1.88, 3.75, 7.5 and 15 mg/mL in 0.1 M NaHCO3). Blood samples are collected serially at appropriate times for the dose-dependency studies, but collected hourly for the infusion studies. Plasma is obtained immediately by centrifugation of blood samples and extracted with acetonitrile and then frozen (-20°C) until assay[1].

[1]. Lin JH, et al. Dose-dependent pharmacokinetics of diflunisal in rats: dual effects of protein binding and metabolism. J Pharmacol Exp Ther. 1985 Nov;235(2):402-6.

[2]. Winter CA, et al. Analgesic activity of diflunisal [MK-647; 5-(2,4-difluorophenyl)salicylic acid] in rats with hyperalgesia induced by Freund's adjuvant. J Pharmacol Exp Ther. 1979 Dec;211(3):678-85.

[3]. Cappon GD, et al. Relationship between cyclooxygenase 1 and 2 selective inhibitors and fetal development when administered to rats and rabbits during the sensitive periods for heart development and midline closure. Birth Defects Res B Dev Reprod Toxicol. 2003 Feb;68(1):47-56.

4-Acetamidophenol | Aspirin | Paradol | Ginsenoside Rg3 | Ginsenoside Compound K | Xanthohumol | Ibuprofen | Diclofenac | NS-398 | Meloxicam | Flufenamic Acid | Epicatechin | Salicylic acid | ketoprofen | Naproxen

MOLECULAR FORMULA :

C13-H8-F2-O3

MOLECULAR WEIGHT :

250.21

WISWESSER LINE NOTATION :

QVR BQ ER BF DF

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human

DOSE/DURATION :

71 mg/kg/5D-I

TOXIC EFFECTS :

Behavioral - tolerance Liver - jaundice, cholestatic

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - man

DOSE/DURATION :

429 mg/kg/17W-I

TOXIC EFFECTS :

Blood - agranulocytosis Nutritional and Gross Metabolic - body temperature increase

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

392 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

159 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

185 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

439 mg/kg

TOXIC EFFECTS :

Behavioral - tremor Behavioral - ataxia Lungs, Thorax, or Respiration - respiratory depression

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

124 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

212 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rabbit

DOSE/DURATION :

603 mg/kg

TOXIC EFFECTS :

Behavioral - tremor Behavioral - ataxia Lungs, Thorax, or Respiration - respiratory depression

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

800 mg/kg/4D-I

TOXIC EFFECTS :

Gastrointestinal - ulceration or bleeding from stomach Related to Chronic Data - death

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

9400 mg/kg/14W-I

TOXIC EFFECTS :

Gastrointestinal - other changes Related to Chronic Data - death

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

520 mg/kg

SEX/DURATION :

female 6-18 day(s) after conception

TOXIC EFFECTS :

Reproductive - Effects on Embryo or Fetus - fetotoxicity (except death, e.g., stunted fetus) Reproductive - Specific Developmental Abnormalities - musculoskeletal system

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

780 mg/kg

SEX/DURATION :

female 6-18 day(s) after conception

TOXIC EFFECTS :

Reproductive - Fertility - post-implantation mortality (e.g. dead and/or resorbed implants per total number of implants)

TYPE OF TEST :

Cytogenetic analysis

TYPE OF TEST :

Cytogenetic analysis

TYPE OF TEST :

Sister chromatid exchange

MUTATION DATA

TEST SYSTEM :

Rodent - mouse

DOSE/DURATION :

350 mg/kg

REFERENCE :

MUREAV Mutation Research. (Elsevier Science Pub. B.V., POB 211, 1000 AE Amsterdam, Netherlands) V.1- 1964- Volume(issue)/page/year: 370,1,1996 *** NIOSH STANDARDS DEVELOPMENT AND SURVEILLANCE DATA *** NIOSH OCCUPATIONAL EXPOSURE SURVEY DATA : NOES - National Occupational Exposure Survey (1983) NOES Hazard Code - X6814 No. of Facilities: 16 (estimated) No. of Industries: 1 No. of Occupations: 1 No. of Employees: 94 (estimated) No. of Female Employees: 62 (estimated)