Inhibition of prostaglandin synthesis and leucocyte migration by flurbiprofen

Experimental murine schistosomiasis: reduced hepatic morbidity after pre- and/or post-infection treatment with ibuprofen or diclofenac sodium

Arachidonic-acid metabolites appear to participate in skin penetration by and transformation of schistosome cercariae and in the pathogenesis of schistosomiasis. With this in mind, mice were treated with one of two cyclooxygenase inhibitors before and/or after infection with Schistosoma mansoni. The effects of the treatment on liver morbidity and the parasitic infection were then evaluated, using infected, untreated and uninfected, treated mice as controls. Treatment with ibuprofen (20 mg/kg.day) or diclofenac sodium (2.5 mg/kg.day) for 7 days before infection led to significantly lower liver weights, worm loads and hepatic hydroxyproline contents than in the untreated mice. If treatment with either drug was continued after infection, for 28 days, there was an additional significant decrease in hepatic gamma-glutamyl transpeptidase activity. All these parameters except liver weight were similarly affected when treatment with either drug was begun on the day of infection and continued for 28 days. There was no significant change in liver weight or worm load when treatment was delayed until day 28 post-infection but faecal egg counts were reduced in the treated groups. In additional experiments, using a smaller dose of diclofenac sodium (1.25 mg/kg.day), all the measured parameters of infection were significantly decreased when the treatment was initiated 7 days before infection and continued until day 28 post-infection. The results indicate that the treatment of S. mansoni-infected mice with ibuprofen or diclofenac sodium was effective in reducing the severity of infection and in attenuating hepatic fibrosis, particularly when the treatment was started early in relation to the time of infection.

Effects of tebufelone (NE-11740), a new anti-inflammatory drug, on arachidonic acid metabolism

Tebufelone is a novel nonsteroidal anti-inflammatory drug (NSAID), of the di-tert-butylphenol (DTBP) class, which displays potent anti-inflammatory, analgesic and anti-pyretic properties in a variety of animal models. In this report, the effects of Tebufelone on arachidonic acid (AA) metabolism are reviewed. Tebufelone potently inhibits the formation of prostaglandins (PGE2) a key mediator of pain and inflammation, in isolated enzyme preparations (IC50 = 1.5 microM, KI = 0.35 microM), two in vitro cellular systems: rat peritoneal macrophages (IC50 = 0.02 microM) and human whole blood (IC50 = 0.08 microM), and ex vivo in man. In addition to PGE2 inhibition, which is common to all NSAIDs, higher concentrations of Tebufelone block the in vitro formation of products of the lipoxygenase pathway [leukotrienes (LTB4)] in rat macrophages (IC50 = 20 microM) and human whole blood (IC50 = 22 microM). Substrate incorporation studies (14C-AA) indicate that Tebufelone reversibly inhibits cyclooxygenase (CO) and 5-lipoxygenase (5-LO) enzymes rather than regulating the release of AA. Tebufelone was shown to be a more potent CO inhibitor than indomethacin and a less potent 5-LO inhibitor than RG-5901. Comparisons to structurally related compounds under development (E-5110, Esai; KME-4, Kanagafuchi), found Tebufelone to be the most potent CO inhibitor in vitro. All three DTBP compounds were equipotent 5-LO inhibitors. It is likely that Tebufelone's inhibitory effects on AA metabolism are, in part, responsible for its in vivo efficacy and enhanced safety profile.

Percutaneous absorption of flurbiprofen in the hairless rat measured in vivo using 19F magnetic resonance spectroscopy

The objective of this investigation was to develop a new methodology using 19F-magnetic resonance spectroscopy (MRS) to measure the in vivo percutaneous absorption of flurbiprofen through hairless rat skin. A 2% W/V flurbiprofen gel (Klucel HF, hydroxypropyl cellulose 1.5% to 2% W/V) containing isopropyl alcohol, water, and propylene glycol (55:35:10 v/v/v) was prepared. A 2-mg dose (100 mg of gel) was applied to the skin of the lower back of an anesthetized hairless rat, contained with a rubber o-ring, and occluded with a lexan plastic cover slip. The animal was placed on an MR surface coil (3.5-cm diameter tuned to 19F) and measurements taken continuously over approximately 3 h in 10-min intervals with a 2-tesla GE CSI nuclear magnetic resonance (NMR) spectrometer. One measures the disappearance of MR signal intensity per interval, which directly relates to the percent of drug disappearance over time, which in turn was converted to a flux value. The flux of flurbiprofen in vivo was found to be 95 +/- 22 micrograms/cm2/h. This is approximately four times greater than the flux of flurbiprofen through excised human skin reported by Akhter and Barry (22 +/- 14 micrograms/cm2/h). This new in vivo method measures drug disappearance and can be readily transferred to man. This method may be adapted to study other fluorine compounds or other nuclei with magnetic properties. It avoids exposure of a patient or animal to the radiation used in x-ray fluorescence methods or to 14C- or 3H-radiolabeled drugs.

The effects of flurbiprofen on the passive transfer of adjuvant-induced arthritis

The effect of flurbiprofen on the passive transfer of adjuvant-induced arthritis was studied to determine if flurbiprofen acted in the donor and/or recipient arms of this model. Groups of donor and recipient rats were treated with either placebo or flurbiprofen 4 mg/kg. Joint scores were markedly decreased in recipient rats treated with flurbiprofen irrespective of the whether donor animals were treated with placebo or flurbiprofen (p less than 0.01). There was also a moderate decrease in the ability of donor cells from rats treated with flurbiprofen to suppress the severity of arthritis (p less than 0.01); however, this effect was less marked than that seen in recipient animals. These data imply that flurbiprofen may act at multiple sites in adjuvant-induced arthritis, but the major site of action of flurbiprofen in this model is in the recipient animals.

The pharmacokinetics of the enantiomers of flurbiprofen in patients with rheumatoid arthritis

Plasma and synovial fluid concentrations of the enantiomers of flurbiprofen were measured in 15 rheumatoid patients receiving 100 mg racemic flurbiprofen twice daily. Pharmacokinetic parameters showed considerable variability within the group of patients, although differences in S(+)/R(-) plasma concentration ratios were small. The average values (+/- s.d.) of oral plasma clearance, volume of distribution and elimination half-life for R(-)-flurbiprofen were 0.075 (+/- 0.066) l min-1, 12.47 (+/- 5.79) l and 138 (+/- 61) min, respectively. The average values (+/- s.d.) of oral plasma clearance, volume of distribution and elimination half-life for S(+)-flurbiprofen were 0.057 (+/- 0.035) l min-1, 12.81 (+/- 4.43) l and 155 (+/- 49) min, respectively. S(+)/R(-) ratios (+/- s.d.) rose from 1.06 (+/- 0.12) to 1.75 (+/- 0.61) at the end of the 12 h interval in plasma and from 1.18 (+/- 0.13) to 1.47 (+/- 0.24) over the measured time course in synovial fluid. Increases in S(+)/R(-) ratios may be clinically important as they demonstrate accumulation of the pharmacologically active species.

Effects of topical applications of meclofenamic acid and ibuprofen on bone loss, subgingival microbiota and gingival PMN response in the primate Macaca fascicularis

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to alter periodontitis in both animals and humans. This study was initiated in the nonhuman primate (Nhp) model to determine the effect of two NSAIDs on preexisting gingivitis, the conversion of gingivitis to periodontitis, the associated subgingival microbiota, and the gingival PMN response. Eighteen cynomolgus monkeys were divided into three groups and treated on a blind basis with ibuprofen 8%, meclofenamic acid 5%, or placebo applied topically 5 days/week for 20 wk. After 4 wk of treatment, periodontitis was initiated in one quadrant by the placement of silk ligatures. Clinical parameters, bone loss by densitometric analysis of radiographs (CADIA), and cultural microbiology of subgingival plaque were monitored. In situ PMN chemotaxis was assessed by quantitating the PMNs which entered the sulcus in response to a challenge with n-formyl-methionyl-leucyl-phenylalanine (FMLP). No significant differences in the clinical parameters were noted by treatment groups. Radiographic bone loss was detected in all experimental sites in placebo animals as compared with 67% and 44% for ibuprofen and meclofenamic acid animals, respectively. Mean CADIA scores/animal showed a significant loss in bone density for placebo at 6 and 16 wk, no change for ibuprofen animals, and a significant increase in density for meclofenamic acid animals. The microbiota of all groups changed with ligation consistent with previous reports of disease initiation in the Nhp.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of flurbiprofen, acetaminophen, an acetaminophen-codeine combination, and placebo in postoperative oral surgery pain

Eighty-eight outpatients with postoperative pain after the surgical removal of impacted third molars were randomly assigned, on a double-blind basis, to receive a single, oral dose of flurbiprofen 100 mg, acetaminophen 600 mg, a combination of acetaminophen 600 mg with codeine 60 mg, or placebo. Using a self-rating record, subjects rated their pain and its relief hourly for 12 hours after medicating. Estimates of sum of pain intensity differences, peak pain intensity differences, total relief, peak relief, and hours of 50% relief were derived from these subjective reports. Flurbiprofen and the acetaminophen-codeine combination were significantly superior to placebo for every measure of total and peak analgesia and significantly superior to acetaminophen alone for most measures of efficacy. Based on the 12-hour data, acetaminophen alone did not differ significantly from placebo; however, it was superior to placebo for measures of total effect based on the 4-hour data. Flurbiprofen was significantly superior to the acetaminophen codeine combination with respect to the number of hours until remedication. All medications had manifested an effect by hour 1; analgesia persisted for 12 hours for flurbiprofen, 6 hours for acetaminophen-codeine, and 3 hours for acetaminophen alone. The frequency of adverse effects was similar for the active medications.

Cutaneous reactions to drugs used for rheumatologic disorders

Cutaneous reactions to medications probably represent the most common manifestation of drug reactions. The diversity of cutaneous eruptions produced by drugs provide a challenge in searching for the mechanisms producing the reaction. Many eruptions are due to a form of allergic hypersensitivity, while others may be idiosyncratic, due to a metabolic abnormality, or represent a cumulative phenomenon. This article discusses the diagnosis of drug-induced cutaneous reactions by reviewing specific drugs commonly used in rheumatologic therapy.

An evaluation of flurbiprofen, aspirin, and placebo in postoperative oral surgery pain

One hundred sixty-four outpatients with postoperative pain after the removal of impacted third molars were randomly assigned on a double-blind basis, to receive oral doses of flurbiprofen 25, 50, or 100 mg; aspirin 600 mg; or placebo. Using a self-rating record, subjects rated their pain and its relief hourly for 8 hours after medicating. Estimates of sum of pain differences (SPID), peak pain intensity difference (PID), total relief, peak relief, and hours of 50% relief were derived from these subjective reports. All active medications were significantly superior to placebo. Analgesia was similar for flurbiprofen 25 mg and aspirin 600 mg. Flurbiprofen 50 and 100 mg were significantly superior to aspirin for every measure of analgesia except peak PID. There was a significant dose-response regression between flurbiprofen 25 mg and both of the higher dosages. Flurbiprofen 50 and 100 mg did not differ significantly, suggesting a plateau in flurbiprofen's analgesia. The analgesic effect of flurbiprofen was significant by hour 1 and persisted for 8 hours. The frequency of adverse effects was similar for the active medications.

Comparative effect of tiaprofenic acid and piroxicam alone and as adjuvants to antibilharzial therapy on pulmonary granuloma in unsensitized mice

Granulomata formed in the liver or lung of man and animals infected with schistosomiasis are common manifestation of an inflammatory delayed hypersensitivity reaction. Non-steroidal anti-inflammatory drugs (NSAIDs) (tiaprofenic acid and piroxicam) have been used alone and as adjuvants to praziquantel in treating pulmonary granulomata induced in mice by injecting them intravenously with S. mansoni eggs. The size of the granulomata, as well as some immunological parameters, have been measured at the end of treatment. Both anti-inflammatory drugs effectively reduced the size of lung granulomata in a dose-dependent manner. The immediate skin reaction and, to a lesser extent, the delayed reaction were reduced by these drugs. Tiaprofenic acid, but not piroxicam, reduced the percent macrophage migration inhibition in vitro. The combined therapy of either of the drugs with praziquantel did not result in an additive effect.

Plasma and synovial fluid kinetics of flurbiprofen in rheumatoid arthritis

Clinical assessment, plasma and synovial fluid kinetics were studied in 29 rheumatoid patients receiving 100 mg flurbiprofen twice daily. Clinical assessment and pharmacokinetic measurements varied widely within the group of patients. The average values for plasma clearance, volume of distribution and elimination halflife of flurbiprofen were 0.65 +/- 0.24 ml min-1 kg-1, 0.160 +/- 0.093 l kg-1 and 3.1 +/- 1.7 h, respectively. Synovial fluid drug concentrations peaked later and were lower than corresponding plasma concentrations: 5.2 h and 4.4 mg l-1 as against 1.49 h and 12.5 mg l-1, respectively. At 48 h after an oral dose of flurbiprofen, all the drug had been cleared from the synovial fluid. Synovial fluid drug concentrations were not related to synovial fluid albumin concentration or pH. There was a weak relationship between synovial fluid drug concentration and the thermographic measurements of disease activity. The fractions of flurbiprofen not bound to protein in synovial fluid and plasma were not significantly different. A simple model is proposed to account for the plasma and synovial fluid pharmacokinetics.

A review of selected investigational nonsteroidal antiinflammatory drugs of the 1980s

We reviewed the literature on 7 investigational nonsteroidal antiinflammatory drugs (NSAIDs): fenbufen, flurbiprofen, tiaprofenic acid, diclofenac, fenclofenac, etodolac and proquazone. These drugs all appear to be at least as effective as currently marketed NSAIDs. Toxicity reported with these newer agents is similar to that seen with other drugs in this class, with gastrointestinal complaints being most commonly reported. The frequency of gastritis and the extent of gastrointestinal microbleeding are less than what occur with aspirin therapy. Fenclofenac may affect thyroid function tests, an effect not noted with other NSAIDs. Proquazone and fenclofenac may have some effect on immunologic function similar to those of slow-acting antirheumatic drugs. These drugs decrease immunoglobulins, rheumatoid factor and C-reactive protein. The place for these drugs in the management of rheumatic diseases has yet to be defined. They may prove to be more beneficial than currently marketed drugs for some patients.

Immunologic effects of nonsteroidal anti-inflammatory agents

The author discusses the evidence that PGE is an immunomodulator and addresses the thesis that nonsteroidal anti-inflammatory agents, by blocking endogenous PGE production, act to partially correct the immunologic aberrations involved in the pathogenesis of rheumatoid arthritis.

In vivo effects of indomethacin and flurbiprofen on the locomotion of neutrophils elicited by immune and non-immune inflammation in the rat

The in vivo effects of indomethacin (3 mg/kg) and flurbiprofen (1.5 mg/kg) were investigated on the development of three different pleural inflammations in the rat and on in vitro locomotion of elicited neutrophils (PMN). Indomethacin and flurbiprofen similarly reduced the development of non-immune pleurisy induced by decomplemented isologous rat serum (DIRS) to a similar degree but had no effect in the delayed hypersensitivity reaction (DHR) model. Flurbiprofen was less effective than indomethacin in the immediate hypersensitivity reaction (IHR) model. PMN elicited by the two immune reactions (IHR and DHR) displayed lower random and directed locomotion than DIRS-elicited PMN. Neither drug interfered with DIRS-elicited PMN locomotion. They inhibited both random migration and directed locomotion of unwashed PMN (i.e. suspended in their original exudate) elicited by IHR or DHR and stimulated by the peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) or isologous rat serum (IRS). Locomotion of washed IHR-elicited PMN stimulated with IRS was also inhibited by the two drugs. The data suggest that these drugs could impair PMN movement at inflammatory sites.

Immunologic effects of nonsteroidal anti-inflammatory drugs

Recent studies of the immunoregulatory effects of prostaglandin and the immunomodulating actions of nonsteroidal anti-inflammatory drugs reveal that earlier reports of inhibition of prostaglandin synthesis by nonsteroidal anti-inflammatory drugs cannot alone fully explain the anti-inflammatory properties of these agents. Data defining the complex inter-relationship of prostaglandin, the immune response, and nonsteroidal anti-inflammatory drugs are reviewed, and possible mechanisms of anti-inflammatory action of these agents are considered. The effects of nonsteroidal anti-inflammatory drugs on cellular immune function and humoral immune response suggest that anti-inflammatory activity may be related to altered suppressor cell function, inhibition of monocyte collagenase release, or inhibition of neutrophil migration and activation. Further elucidation is awaited.

In vivo interaction of nonsteroidal anti-inflammatory drugs on the locomotion of neutrophils elicited by acute non-specific inflammations in the rat--effect of indomethacin, ibuprofen and flurbiprofen

The in vivo effects of Flurbiprofen, Ibuprofen and Indomethacin (1.5, 6 and 3 mg/kg respectively) were studied on two acute non-specific pleurisies induced by calcium pyrophosphate crystals (CaPP) or decomplemented isologous rat serum (DIRS) in the rat. Drug effects on the exudation phase (pleural exudate volume), leukocyte emigration (number of leukocytes in the fluid) and on random and directed locomotion of elicited neutrophils (PMN) under agarose were investigated. In the CaPP model, Indomethacin, Flurbiprofen and Ibuprofen reduced the pleural exudate volume by approximately 48, 57 and 22% respectively while leukocyte emigration was inhibited 50, 45 and 50% respectively. In the DIRS model Indomethacin and Flurbiprofen reduced the exudate volume by 54 and 52% and leukocyte emigration by 51 and 31% respectively. Ibuprofen administration produced a decrease in exudate volume of only 27%. The three drugs did not alter in vitro locomotion of DIRS-elicited PMN. On the other hand, Flurbiprofen reduced both random and directed locomotion of CaPP-elicited PMN stimulated with peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP), isologous rat serum (IRS) or cell-free exudates. Ibuprofen induced a slight increase in random migration of CaPP-elicited PMN while Indomethacin was without effect. None of the three drugs altered the chemotactic activity of inflammatory exudate. These data suggest that therapeutic doses of anti-inflammatory drugs interfere with PMN at inflammatory sites and induce modifications in their movement per se which persist after cell washing.

Mechanism of action of nonsteroidal anti-inflammatory agents

Recent data from several laboratories, which suggest that generally accepted concepts relating to the mechanism of action of nonsteroidal, anti-inflammatory drugs (NSAIDs) in rheumatoid arthritis may be incorrect, are reviewed. Over the past decade, most researchers have espoused the idea that NSAIDs act by inhibiting cyclooxygenase, thereby removing prostaglandins, which are thought to be responsible for pain and inflammation. Recent studies demonstrating that prostaglandins have important immunomodulating properties and that NSAIDs actually provide partial correction of several immunoregulatory dysfunctions in patients with rheumatoid arthritis are described. In addition, some NSAIDs inhibit migration along with other monocyte and polymorphonuclear leukocyte functions. Data suggest that these actions are not related to inhibition of cyclooxygenase.

The anti-inflammatory action of flurbiprofen suppositories in paediatric urology in comparison with co-trimoxazole

Fifty male children, aged between 3 and 10 years, were treated for a 12-day period with either trimethoprim (80-160 mg) plus sulphamethoxazole (400-800 mg) daily (co-trimoxazole) or 50-125 mg/day flurbiprofen rectally. The patients had been treated surgically for criptorchidism. Flurbiprofen showed good effectivity in controlling post-operative inflammation in urology. It is concluded that antimicrobial agents such as cotrimoxazole, because of their potential risks of damage at the cell's level, should be used only in presence of a bacterial infection.

Does the addition of ketotifen to non-steroidal anti-inflammatory drugs confer any additional benefit in rheumatoid arthritis?

Ketotifen (benzocycloheptathiophene) was evaluated in a double-blind study of patients with active rheumatoid arthritis. Sixty patients were randomly allocated to receive active or matching placebo drug and reviewed 6 weekly for 24 weeks. Conventional NSAIDs were continued throughout. Disease activity was assessed clinically and biochemically at weeks 0, 12 and 24. Nineteen patients remained on active drug for 24 weeks and 11 on placebo. Significant improvement in articular index was seen in both groups but no objective improvement was noted in either group. No undue toxicity was encountered in either group. Use of a drug considered to have selective LTC4 and LTD4 antagonism in combination with conventional cyclo-oxygenase inhibitors did not confer any additional benefit in rheumatoid arthritis.

The effects of flurbiprofen and indomethacin on the mitogenic response of human peripheral mononuclear cells

The effects of flurbiprofen (FBP) and indomethacin (INDO) on the incorporation of [3H]thymidine into human peripheral mononuclear cells after stimulation with phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were investigated. FBP and INDO enhanced [3H]thymidine incorporation only at suboptimal concentrations of PHA and Con A but the concentration of PWM was less critical. Enhancement depended upon the presence of mononuclear cells which could be removed by adherence to plastic: these may be tentatively identified as monocytes (macrophages). INDO enhanced [3H]thymidine uptake to a greater degree than FBP and its effect was decreased to a greater extent by removal of monocytes. The enhancing effects of INDO and FBP are completely reversible by thorough washing of cells which had been exposed to the drugs and could be regained by direct addition of drugs to previously washed cells. Concurrent addition of both drugs to cell cultures showed neither antagonism nor synergy with respect to the effect of one drug alone. PGE2 inhibited [3H]thymidine incorporation. Like that of FBP and INDO, this action was dependent on mitogenic dose and apparent at suboptimal doses only. A low concentration of exogenous PGE2 (2 ng/ml) was sufficient to prevent the enhancing effect of both FBP and INDO.

A multicentre comparison of flurbiprofen and naproxen in rheumatoid arthritis: a four-week study in 118 patients

One-hundred and eighteen patients with rheumatoid arthritis were treated for 4 weeks with flurbiprofen 300 mg/day (sixty patients) or naproxen 750 mg/day (fifty-eight patients) in a six-centre randomized trial. Flurbiprofen proved to be more effective than naproxen in reducing morning stiffness (p less than 0.01), Ritchie articular index (p less than 0.01) and number of swollen joints (p less than 0.05) and in relieving night pain (p less than 0.01). The incidence and severity of side-effects, mainly gastric, were both low and similar with flurbiprofen (17%) and naproxen (19%).

Treatment of rheumatoid arthritis with flurbiprofen: a comparison with enteric-coated aspirin

Forty patients with definite or classical rheumatoid arthritis were entered for 3 months in a double-blind trial, 20 patients each on 200 mg flurbiprofen or 4.0 g enteric-coated aspirin daily. Statistically significant improvements (Page Test, p less than 0.05) on flurbiprofen were reported during the course of the study for 7 out of 20 parameters: degree of pain, duration of morning stiffness, grip strength, torquometer, Ritchie articular index, number of swollen joints and patient's overall assessment, while for aspirin a significant improvement was reported for 5 parameters: degree of pain, PIP joint size, Ritchie articular index and physician's overall assessment. The amount of improvement between flurbiprofen and enteric-coated aspirin differed significantly (Kruskal-Wallis H Test) only for 2 parameters: Ritchie articular index and number of swollen joints. In both cases the degree of improvement was greater on flurbiprofen than an aspirin. Side-effects were reported for 7 patients receiving aspirin (2 of which were severe enough that treatment had to be stopped) and for 3 patients receiving flurbiprofen. Except for 2 cases of tinnitus on aspirin, the side-effects were mostly gastro-intestinal in nature. A significant decrease was found for patients receiving aspirin. A significant increase in blood urea occurred on flurbiprofen. Most values, however, remained within normal limits. The results suggests that flurbiprofen is better tolerated and at least as effective as enteric-coated aspirin in the treatment of patients with rheumatoid arthritis.

The effects of non-steroid anti-inflammatory drugs on leukocyte migration in carrageenin-induced inflammation

Some non-steroid anti-inflammatory drugs which inhibit arachidonate cyclo-oxygenease have been examined for their effects on leukocyte migration, prostaglandin production and oedema formation in carrageenin-induced inflammation in the rat. At doses which inhibited oedema, all the drugs tested caused a dose-dependent reduction in numbers of leukocytes and prostaglandin concentrations in 24-h inflammatory exudates. At lower doses, indomethacin, aspirin, sodium salicylate, flurbiprofen and phenylbutazone significantly potentiated leukocyte migration by 20-70%. Ibuprofen, naproxen and BW755C reversed the indomethacin-induced increase in leukocyte accumulation. BW755C inhibits the generation of chemotactic lipoxygenase products and it is possible that the effects of all these drugs on leukocyte migration are mediated through the lipoxygenase pathway of arachidonic acid metabolism.

Concentrations of flurbiprofen in serum and synovial fluid from patients with active rheumatoid disease: some preliminary observations

In 3 patients with active rheumatoid disease, concentrations of flurbiprofen of approximately 2 microgram per ml were achieved in synovial fluid 3 hours after a single oral dose of flurbiprofen (100 mg). The highest concentrations were seen between 3 and 9 hours after administration of the dose. The concentration of flurbiprofen in synovial fluid seemed to fall more slowly than in the circulation, but more extensive data would be needed to confirm this. In all 3 patients the drug was absorbed rapidly into the circulation, the highest serum concentrations of 7 microgram to 9 microgram per ml being seen in the first blood sample withdrawn 1.5 hours after administration of the dose. Serum concentrations fell with a mean apparent half-life of approximately 3 hours.