Clinical safety of flurbiprofen

Pharmacokinetic interactions of curcuminoids with conventional drugs: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Herb-drug interactions are of great concern in health practices. Curcumin is a natural polyphenol extracted from turmeric, a spice widely used all over the world. Curcumin is clinically used due to its acceptable safety profile and therapeutic efficacy.

AIM OF THE STUDY

Current paper aims to highlight the effect of curcumin on concomitantly used drugs.

METHODS

Electronic databases including PubMed, Scopus and Science Direct were searched with the keywords "curcumin" in the title/abstract and "drug interaction," "drug metabolism," "cytochrome," "P-glycoprotein" and "P450" in the whole text.

RESULTS

Curcumin can induce pharmacokinetic alterations such as changes in C_max and AUC when concomitantly used with pharmacological agents like cardiovascular drugs, antidepressants, anticoagulants, antibiotics, chemotherapeutic agents, and antihistamines. The underlying mechanisms of these interactions include inhibition of cytochrome (CYP) isoenzymes and P-glycoprotein. There is only one clinical trial which proved a significant alteration of conventional drugs in concomitant use with curcumin indicating the need for further human studies.

CONCLUSIONS

Although in vitro and in vivo studies do not provide enough evidence to judge the clinical drug interactions of curcumin, physicians must remain cautious and avoid drug combinations which may lead to curcumin-drug interactions.

A randomised, two-period, cross-over, open-label study to evaluate the pharmacokinetic profiles of single doses of two different flurbiprofen 8.75-mg lozenges in healthy volunteers

AIMS

To compare the bioavailability of a new oromucosal formulation of flurbiprofen 8.75-mg lozenges, developed by Alfa Wassermann S.p.A. (test drug) to that of marketed flurbiprofen 8.75-mg lozenges (Benactiv Gola®, reference drug).

METHODS

This was an open, randomised, two-period, crossover, pharmacokinetic (PK) study in which flurbiprofen plasma levels were compared in 12 healthy volunteers after the administration of single doses (8.75 mg × 2) of two different oromucosal lozenges to be sucked and slowly dissolved in the mouth. A wash-out period of at least 7 days separated the two study periods. Blood samples were collected prior to dosing and at predefined intervals for 24 h after dose. Flurbiprofen plasma concentrations were determined by liquid chromatography/tandem mass spectrometry. PK parameters maximum plasma concentration (C(max)), time to maximum plasma concentration (T(max)), area under the plasma concentration-time curve from time zero to 24 hours (AUC(0-t)), area under the plasma concentration-time curve from time zero to infinity (AUC(0-)∞) and half-life were calculated and compared by analysis of variance using treatment, period and sequence as sources of variation. Bioequivalence between the two formulations was based on 90% confidence intervals of the ratio of the geometric means of C(max) and AUC falling within the 0.80-1.25 range as defined in bioequivalence guidelines by regulators. Tolerability of the two formulations was assessed by adverse event monitoring, routine laboratory tests, physical examination, electrocardiographic tracing and vital sign measurements.

RESULTS

All enrolled subjects completed the study. Bioequivalence without significant treatment effect was demonstrated between the test drug/reference drug ratios of mean C(max) and AUCs. Moreover, mean T(max) was superimposable. No safety parameter presented a clinically relevant variation after administration of either formulation that were therefore well tolerated.

CONCLUSION

The new formulation of flurbiprofen 8.75-mg compressed lozenges developed by Alfa Wassermann S.p.A. is bioequivalent to the reference product flurbiprofen 8.75-mg lozenges (Benactiv Gola) in healthy volunteers.

Efficacy and tolerability of a topical NSAID patch (local action transcutaneous flurbiprofen) and oral diclofenac in the treatment of soft-tissue rheumatism

The efficacy and safety of local action transcutaneous flurbiprofen 40 mg [flurbiprofen LAT] patches and diclofenac sodium tablets, 50 mg b.d., were compared in an open, multicentre, randomized, parallel-group study in patients with soft-tissue rheumatism. Patches were replaced at 12-hourly intervals. Clinical assessments were performed after 7 and 14 days of treatment. Fifty-six patients were treated with flurbiprofen LAT and 53 with diclofenac. Six withdrawals (three from each group) occurred during the treatment period. A statistically significant difference was observed in favour of flurbiprofen LAT for the principal measure, namely the investigator's opinion of overall change in clinical condition: 49/53 (92%) patients treated with flurbiprofen LAT had improved by day 14 compared with 36/49 (73%) patients receiving diclofenac sodium (p = 0.03; eligible dataset). There were also statistically significant differences in favour of flurbiprofen LAT for the investigator's assessments of the overall severity of the clinical condition (p = 0.03; eligible dataset), for the severity of pain at the region treated (p = 0.04; intent-to-treat), and for the severity of tenderness (p < 0.001; intent-to-treat). Supplementary analgesia (paracetamol) was required by two patients in the flurbiprofen LAT group and by eight diclofenac-treated patients. The difference in favour of flurbiprofen LAT in the average daily consumption of paracetamol was significant (p = 0.04). The patients' assessment of severity of pain on movement also favoured flurbiprofen LAT (p = 0.049; eligible dataset), but there were no statistically significant differences in day or night pain or quality of sleep. For the patients' opinion of treatment there was, however, a statistically significant difference in favour of flurbiprofen LAT (p = 0.02). Of the patients receiving flurbiprofen LAT, 94% regarded it as a convenient form of treatment. With respect to tolerability 8/56 (14%) patients applying flurbiprofen patches reported a total of nine adverse effects (AEs) (mainly local, mild skin irritations), vs 9/52 (17%) patients receiving diclofenac, who reported 12 AEs. Most AEs in the enteric-coated diclofenac group were of a gastrointestinal nature (one of which was severe). In terms of the proportion of patients reporting AEs related to the digestive system, there was a statistically significant difference in favour of flurbiprofen LAT (p = 0.011). In conclusion, local treatment of soft-tissue rheumatism with flurbiprofen LAT was demonstrably superior to benchmark oral therapy with diclofenac sodium over a 2-week period in terms of both efficacy and gastrointestinal tolerability. Flurbiprofen LAT provided both an effective and convenient form of topical SAID treatment.

Pharmacokinetic comparison of oral and local action transcutaneous flurbiprofen in healthy volunteers

Flurbiprofen is a propionic acid-derived non-steroidal anti-inflammatory drug (NSAID) used widely in the treatment of rheumatism and non-arthritic pain. The pharmacokinetics of topically and orally administered flurbiprofen were compared in a two-part, open study involving healthy adult volunteers. In the first (cross-over) part of the study, 12 Caucasians were randomized to receive either a single oral dose of 50 mg flurbiprofen or a single topical application of a novel 40 mg flurbiprofen-containing patch on the right wrist for 12 h. In the second part of the study, each subject applied a flurbiprofen-containing patch twice daily to the same wrist for 7 days. Plasma concentrations of flurbiprofen and urinary concentrations of the NSAID and its metabolites were measured by high-performance liquid chromatography assay, to enable comparison of the pharmacokinetic parameters for delivery of the drug by both routes. Maximum concentrations of the NSAID in plasma (Cmax) were much lower after a single application of the topical 40 mg flurbiprofen patch than after a single oral dose of 50 mg of the NSAID (mean +/- SD: 43 +/- 16 ng/ml versus 5999 +/- 1300 ng/ml, respectively). After repeated application of the topical patch, Cmax increased only slightly to 103 +/- 57 ng/ml. The mean relative bioavailability of flurbiprofen from the patch was 3.5 +/- 1.7%, calculated from plasma area under the curve data and 4.4 +/- 2.8% from urinary excretion data.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical pharmacokinetics of flurbiprofen and its enantiomers

Flurbiprofen is a chiral nonsteroidal anti-inflammatory drug (NSAID) of the 2-arylpropionic acid class. Although it possesses a chiral centre, with the S-(+)-enantiomer possessing most of the beneficial anti-inflammatory activity, both enantiomers may possess analgesic activity and all flurbiprofen preparations to date are marketed as the racemate. Flurbiprofen exhibits stereoselectivity in its pharmacokinetics. Stereoselectivity is exhibited at the level of protein binding and metabolite formation. Hence, the data generated using nonstereoselective assays may not be used to explain the pharmacokinetics of individual enantiomers. The absorption of flurbiprofen is rapid and almost complete when given orally. The area under the plasma concentration-time curve of flurbiprofen is proportional to the dose administered to patients. Sustained release dosage forms are available, which may be beneficial due to the short terminal phase elimination half-life of conventional immediate release flurbiprofen (3 to 6 hours). They may also decrease local gastrointestinal adverse effects. Although with these preparations the peak plasma drug concentration is reduced and time taken to achieve peak concentrations is prolonged, the bioavailability is the same as that with regular release counterparts. Flurbiprofen binds extensively to plasma albumin, apparently in a stereoselective manner. Substantial concentrations of the drug are attained in synovial fluid, which is the proposed site of action of NSAIDs. There is negligible R to S inversion after oral administration. Flurbiprofen is eliminated following extensive biotransformation to glucuro-conjugated metabolites. Conjugates are excreted in urine, and approximately 20% of flurbiprofen is eliminated unchanged. The excretion of conjugates may be tied to renal function as accumulation of conjugates occurs in end-stage renal disease, but not in young individuals or elderly patients. Although flurbiprofen is excreted into breast milk, the amount of drug transferred comprises only a small fraction of the maternal exposure. Significant drug interactions have been demonstrated for aspirin (acetylsalicylic acid), coumarins and propranolol. The relationship between concentration and anti-inflammatory and analgesic effect has yet to be elucidated for this drug.

An association between recurrent oro-genital ulceration and non-steroidal anti-inflammatory drugs

Recurrent oro-genital ulceration is a common condition of unknown aetiology. This paper describes a patient who had severe recurrent oro-genital ulceration which was unresponsive to conventional therapy. The patient was taking non-steroidal anti-inflammatory drugs (NSAIDs) prescribed for osteoarthritis. When she stopped this medication, she had no further genital ulceration and the pattern of her oral ulceration was dramatically improved. There have been no previously reported cases of recurrent oro-genital ulceration associated with NSAIDs.

Assessing physician choice of nonsteroidal antiinflammatory drugs in a health maintenance organization

OBJECTIVE

To develop a categorization scheme for grouping various nonsteroidal antiinflammatory drugs (NSAIDs) by relative safety; to develop a method to quantify the appropriateness of the initial and subsequent choices of NSAID therapy; to assess whether NSAID prescribing was consistent with the developed criteria; to examine the cost of inappropriate, acute NSAID use as defined by the established criteria.

DESIGN

Retrospective drug utilization review focusing on NSAIDs.

SETTING/PARTICIPANTS

Members aged > or = 18 years of a 40,000-person southeastern Michigan health maintenance organization.

MAIN OUTCOME MEASURES

(1) Appropriateness of therapy using a four-level safety classification system for the NSAIDs developed by a consensus process; criteria based on safety under the assumption that any particular NSAID is equally likely to be effective when dosed appropriately; (2) evaluation of progression of NSAID therapy using the NSAID Therapy Progression Formula.

RESULTS

For acute patients, almost half of the prescriptions were for ibuprofen and 33 percent were for naproxen. Ibuprofen usage accounted for 16 percent of total NSAID cost and naproxen agents accounted for over 50 percent of that cost. Potential cost savings of approximately $82,000 probably would have occurred had a 50 percent interchange rate for ibuprofen been acceptable. For chronic patients, 85 percent were treated with one or two NSAIDs; treatments were of reasonable high quality when compared by safety profiles. There was low use of ibuprofen in patients who only received one NSAID.

CONCLUSIONS

NSAID usage assessment in a large population was achieved by developing a classification and scoring system based on NSAID safety; in this population, prescribing patterns were generally consistent with established criteria; however, when considering cost, improvement in initial NSAID selection for acute patients was possible.

The propionic acids: a personal perspective

In searching during the early 1950s for new drugs for the treatment of rheumatoid arthritis, little information was available to allow a rational approach. The mode of action of the few drugs available was unknown and even the analgesic action of aspirin could not be demonstrated in animals. A speculative concept was developed that aspirin possessed a specific unidentified action in rheumatoid arthritis and that this and its analgesic properties were related to its ability to delay the development of ultraviolet (UV) erythema in the guinea pig. A series of substituted phenoxypropionic acids proved to be active as antierythemic agents, but the most potent was inactive clinically in rheumatoid arthritis. Refinements to the testing systems led to a series of substituted phenylacetic acids, three of which although active in rheumatoid arthritis produced unacceptable adverse reactions (ADRs). Attempts to relate laboratory data to clinical ADRs suggested that the substituted phenylpropionic acids (originally rejected because of concerns about toxicity) might be better tolerated than we had anticipated. Ibuprofen was selected from this large group. It was proven to be effective and well tolerated and became "the first of the propionics" when it was launched in 1969. In the 1970s, ibuprofen proved to be effective as a prescription drug in a range of painful nonrheumatic conditions and on the basis of its good safety record was approved as an OTC analgesic in 1983 in the United Kingdom and in 1984 in the USA. It has proven to be popular and effective and much safer than aspirin or acetaminophen in overdosage.