Nonsteroid drug selectivities for cyclo-oxygenase-1 rather than cyclo-oxygenase-2 are associated with human gastrointestinal toxicity: a full in vitro analysis

A review of intranasal ketorolac tromethamine for the short-term management of moderate to moderately severe pain that requires analgesia at the opioid level

BACKGROUND

An intranasal (IN) formulation of ketorolac was recently FDA approved in adult patients for the short-term management of moderate to moderately severe pain that requires analgesia at the opioid level.

SCOPE

The aim of this paper is to provide an overview of the clinical pharmacology, pharmacokinetics, efficacy, and tolerability of IN ketorolac. Databases used for this literature search include PubMed, International Pharmaceutical Abstracts, Cochrane Library and ClinicalTrials.gov from January 1980 to January 2012. All primary papers on IN ketorolac were eligible, including pharmacologic, pharmacokinetic, clinical, outcomes, and meta-analyses. The approved product labeling was a source of information, as well as the bibliographies of published articles which were reviewed for additional pertinent literature.

FINDINGS

The search yielded six relevant studies all of which were selected for this review and included efficacy and safety trials, one pharmacokinetics study, and one preclinical study. IN ketorolac is a non-steroidal inflammatory drug that exhibits its effect mainly by inhibiting cyclo-oxygenase (COX) 1 and 2 with high affinity for COX-1. Absorption of IN ketorolac displays a median t(max) of 0.50-0.75 hours and has a t(½) of approximately 5-6 hours. Primary analyses included evaluation of morphine use and summed pain intensity difference (SPID) which was assessed using a visual analog scale. In one of the two phase III studies, the mean SPID6 score was 83.3 in the IN ketorolac group versus 37.2 in the placebo group, p = 0.007. In another phase III study, the mean SPID6 score was 117.4 in the IN ketorolac group versus 89.9 in the placebo group, p = 0.032. IN ketorolac was well-tolerated with most adverse events associated with the route of administration.

CONCLUSION

Based on the clinical trials reviewed, IN ketorolac was associated with significant pain reduction in patients with various post-operative procedures, with good tolerability.

Nonsteroidal anti-inflammatory drugs in the treatment of low back pain

Low back pain (LBP) is amongst the top ten most common conditions presenting to primary care clinicians in the ambulatory setting. Further, it accounts for a significant amount of health care expenditure; indeed, over one third of all disability dollars spent in the United States is attributable to low back pain. In most cases, acute low back pain is a self-limiting disease. There are many evidence-based guidelines for the management of LBP. The most common risk factor for development of LBP is previous LBP, heavy physical work, and psychosocial risk factors. Management of LBP includes identification of red flags, exclusion of specific secondary causes, and comprehensive musculoskeletal/neurological examination of the lower extremities. In uncomplicated LBP, imaging is unnecessary unless symptoms become protracted. Reassurance that LBP will likely resolve and advice to maintain an active lifestyle despite LBP are the cornerstones of management. Medications are provided not because they change the natural history of the disorder, but rather because they enhance the ability of the patient to become more active, and in some cases, to sleep better. The most commonly prescribed medications include nonsteroidal anti-inflammatory drugs (NSAIDs) and muscle relaxants. Although NSAIDs are a chemically diverse class, their similarities, efficacy, tolerability, and adverse effect profile have more similarities than differences. The most common side effects of NSAIDs are gastrointestinal. Agents with cyclo-oxygenase 2 selectivity are associated with reduced gastrointestinal bleeding, but problematic increases in adverse cardiovascular outcomes continue to spark concern. Fortunately, short-term use of NSAIDs for LBP is generally both safe and effective. This review will focus on the role of NSAIDs in the management of LBP.

Synthesis and evaluation of antiinflammatory, analgesic and ulcerogenic potential of NSAIDs bearing 1,3,4-oxadiazole scaffold

Synthesis of 1,3,4-oxadiazole derivatives of diclofenac and mefenamic acid are described. The target compounds 5-[2-(2,6-dichloroanilino)benzyl]-2-aryl-1,3,4-oxadiazole (3a-3e) and 5-[2-(2,3-dimethylanilino)phenyl]-2-(aryl)-1,3,4-oxadiazole (6a-6e) were obtained by treating 2 and 5 with various aromatic acids using POCl₃ as dehydrating agent. They were purified and characterized by IR, ¹H-NMR and elemental analysis. These compounds were further subjected to antiinflammatory, analgesic and acute ulcerogenic activity. Compound 3c and 6d exhibited good antiinflammatory activity and compounds 3c, 3e, 6c, 6d, 6e were found to be non ulcerogenic.

Ts6 and Ts2 from Tityus serrulatus venom induce inflammation by mechanisms dependent on lipid mediators and cytokine production

Inflammatory mediators are thought to be involved in the systemic and local immune response induced by the Tityus serrulatus scorpion envenomation. New functional aspects of lipid mediators have recently been described. Here, we examine the unreported role of lipid mediators in cell recruitment to the peritoneal cavity after an injection with Ts2 or Ts6 toxins isolated from the T. serrulatus scorpion venom. In this report, we demonstrate that following a single intraperitoneal (i.p.) injection of Ts2 or Ts6 (250 μg/kg) in mice, there was an induction of leukocytosis with a predominance of neutrophils observed at 4, 24, 48 and 96 h. Moreover, total protein, leukotriene (LT)B(4), prostaglandin (PG)E(2) and pro-inflammatory cytokine levels were increased. We also observed an increase of regulatory cytokines, including interleukin (IL)-10, after the Ts2 injection. Finally, we observed that Ts2 or Ts6 injection in 5-lipoxygenase (LO) deficient mice and in wild type (WT) 129sv mice pre-treated with LTs and PGs inhibitors (MK-886 and celecoxib, respectively) a reduction the influx of leukocytes occurs in comparison to WT. The recruitment of these cells demonstrated a phenotype characteristic of neutrophils, macrophages, CD4 and CD8 lymphocytes expressing GR1+, F4/80+, CD3+/CD4+ and CD3+/CD8+, respectively. In conclusion, our data demonstrate that Ts2 and Ts6 induce inflammation by mechanisms dependent on lipid mediators and cytokine production. Ts2 may play a regulatory role whereas Ts6 exhibits pro-inflammatory activity exclusively.

Decreased cyclooxygenase inhibition by aspirin in polymorphic variants of human prostaglandin H synthase-1

OBJECTIVES

Aspirin (ASA), a major antiplatelet and cancer-preventing drug, irreversibly blocks the cyclooxygenase (COX) activity of prostaglandin H synthase-1 (PGHS-1). Considerable differences in ASA effectiveness are observed between individuals, and some of this variability may be due to PGHS-1 protein variants. Our overall aim is to determine which, if any, of the known variants in the mature PGHS-1 protein lead to functional alterations in COX catalysis or inhibition by ASA. The present study targeted four PGHS-1 variants: R53H, R108Q, L237M, and V481I.

METHODS

Wild-type human PGHS-1 and the four polymorphic variants were expressed as histidine-tagged, homodimeric proteins in insect cells using baculovirus vectors, solubilized with a detergent, and purified by affinity chromatography. The purified proteins were characterized in vitro to evaluate COX and peroxidase (POX) catalytic parameters and the kinetics of COX inhibition by ASA and NS-398.

RESULTS

Compared with the wild type, several variants showed a higher COX/POX ratio (up to 1.5-fold, for R108Q), an elevated arachidonate Km (up to 1.9-fold, for R108Q), and/or a lower ASA reactivity (up to 60% less, for R108Q). The decreased ASA reactivity in R108Q reflected both a 70% increase in the Ki for ASA and a 30% decrease in the rate constant for acetyl group transfer to the protein. Computational modeling of the brief ASA pulses experienced by PGHS-1 in circulating platelets during daily ASA dosing predicted that the 60% lower ASA reactivity in R108Q yields a 15-fold increase in surviving COX activity; smaller, approximately two-fold increases in surviving COX activity were predicted for L237M and V481I. NS-398 competitively inhibited COX catalysis of the wild type (Ki=6 µmol/l) and inhibited COX inactivation by 1.0 mmol/l ASA in both the wild type (IC50=0.8 µmol/l) and R108Q (IC50=2.1 µmol/l).

CONCLUSION

Of the four PGHS-1 variants examined, R108Q exerts the largest functional effects, with evidence for impaired interactions with a COX substrate and inhibitors. As Arg108 is located on the protein surface and not in the active site, the effects of R108Q suggest a novel, unsuspected mechanism for the modulation of the PGHS-1 active site structure. The lower intrinsic ASA reactivity of R108Q, V481I, and L237M, combined with the rapid hydrolysis of ASA in the blood, suggests that these variants decrease the antiplatelet effectiveness of the drug. These PGHS-1 variants are uncommon but ASA is used widely; hence, a considerable number of individuals could be affected. Further examination of these and other PGHS-1 variants will be needed to determine whether PGHS-1 genotyping can be used to personalize anti-COX therapy.

Pharmacogenetics of nonsteroidal anti-inflammatory drugs

With the beginning of the Human Genome Project, an emerging field of science was brought to the forefront of the pharmaceutical community. Pharmacogenetics facilitates optimization of the current patient-centered care model and pharmacotherapy as a whole. Utilizing these ever-expanding branches of science to nonsteroidal anti-inflammatory drugs (NSAIDs) can provide novel opportunities to affect patient care. With a wide range of NSAID choices available as treatment options for relieving pain and/or reducing inflammation or fever, a more systematic way of selecting the ideal agent for the patients based upon their genetic information could spare them from a potentially permanent health-care condition. Furthermore, if a patient possesses or lacks certain alleles, serious adverse events can be anticipated and avoided. The tailoring of drug therapy can be achieved using the published data and cutting-edge genetic testing to attain a higher standard of care for patients.

Defining the COX inhibitor selectivity of NSAIDs: implications for understanding toxicity

The hypothesis that the anti-inflammatory activity of NSAIDs derives from COX inhibition is well established. It also underpins the accepted mechanism of the gastrointestinal and renal toxicity of NSAIDs. However, in terms of NSAID-induced cardiovascular toxicity, is COX inhibition then guilty by association? Multiple experimental models of COX-1/COX-2 inhibition have enabled ranking of the relative inhibitory activity of NSAIDs. Inhibition is expressed as an IC(50) value and the index of COX selectivity as the ratio of the IC(50) value for COX-2 and COX-1. These data informed the 'imbalance hypothesis' that the cardiovascular risk of NSAIDs results from an imbalance in the detrimental actions of COX-1-derived thromboxane A(2) and the beneficial actions of COX-2-derived prostacyclin (PGI(2)). Data derived from in vitro models used to generate NSAID IC(50) values are discussed in the context of the difficulties in defining COX selectivity and hence understanding the toxicity of NSAIDs in current clinical use.

Lobolide, a diterpene, blockades the NF-κB pathway and p38 and ERK MAPK activity in macrophages in vitro

AIM

Recent studies have shown that constitutive activation of the nuclear factor κB (NF-κB) plays a key role in chronic inflammation and cancers. The aim of this study was to characterize lobolide, a cembrane diterpene, as a drug candidate targeting the NF-κB signaling pathway.

METHODS

A HEK 293/NF-κB-Luc stable cell line was constructed to evaluate the effect of lobolide on NF-κB activation. THP-1 human monocytes and peripheral blood mononuclear cells (PBMCs) from healthy volunteers were tested. Lipopolysaccharide (LPS)-induced TNFα and IL-1β production and activation of the TAK1-IKK-NF-κB pathway were studied using ELISA and Western blot analysis.

RESULTS

In HEK 293/NF-κB-Luc stable cells, lobolide (0.19-50 μmol/L) inhibited NF-κB activation in a concentration-dependent manner with an IC(50) value of 4.2 ± 0.3 μmol/L. Treatment with lobolide (2.5-10 μmol/L) significantly suppressed LPS-induced production of TNFα and IL-1β in both THP-1 cells and PBMCs. In THP-1 cells, the suppression was partially caused by blockade of the translocation of NF-κB from the cytoplasm to the nucleus via affecting the TAK1-IKK-NF-κB pathway and p38 and ERK MAPK activity.

CONCLUSION

Lobolide is a potential inhibitor of the NF-κB pathway, which blocks the translocation of NF-κB from the cytoplasm to the nucleus. Lobolide inhibits LPS-stimulated TNFα and IL-1β release, suggesting that the compound might be an anti-inflammatory compound.

Clinical management of patients with a history of urticaria/angioedema induced by multiple NSAIDs: an expert panel review

Nonsteroidal anti-inflammatory drugs (NSAIDs) represent one of the most frequent causes of drug-induced urticaria/angioedema worldwide. Recent review articles have classified patients experiencing NSAID-induced urticaria/angioedema into different categories, including single reactors, multiple reactors, and multiple reactors with underlying chronic urticaria. Each of these categories requires a different clinical approach. The present article, written by a panel of experts, reports the main recommendations for the practical clinical management of patients with a history of urticaria/angioedema induced by multiple NSAID based on current knowledge.

Indomethacin-induced translocation of bacteria across enteric epithelia is reactive oxygen species-dependent and reduced by vitamin C

The enteric epithelium must absorb nutrients and water and act as a barrier to the entry of luminal material into the body; this barrier function is a key component of innate immunity. Nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy occurs via inhibition of prostaglandin synthesis and perturbed epithelial mitochondrial activity. Here, the direct effect of NSAIDs [indomethacin, piroxicam (cyclooxygenase 1 and 2 inhibitors), and SC-560 (a cyclooxygenase 1 inhibitor)] on the barrier function of human T84 epithelial cell line monolayers was assessed by transepithelial electrical resistance (TER) and internalization and translocation of a commensal Escherichia coli. Exposure to E. coli in the presence and absence of drugs for 16 h reduced TER; however, monolayers cotreated with E. coli and indomethacin, but not piroxicam or SC-560, displayed significant increases in internalization and translocation of the bacteria. This was accompanied by increased reactive oxygen species (ROS) production, which was also increased in epithelia treated with E. coli only. Colocalization revealed upregulation of superoxide synthesis by mitochondria in epithelia treated with E. coli + indomethacin. Addition of antioxidants (vitamin C or a green tea polyphenol, epigallocathechin gallate) quenched the ROS and prevented the increase in E. coli internalization and translocation evoked by indomethacin, but not the drop in TER. Evidence of increased apoptosis was not observed in this model. The data implicate epithelial-derived ROS in indomethacin-induced barrier dysfunction and show that a portion of the bacteria likely cross the epithelium via a transcellular pathway. We speculate that addition of antioxidants as dietary supplements to NSAID treatment regimens would reduce the magnitude of decreased barrier function, specifically the transepithelial passage of bacteria.

Influence of oxytetracycline on carprofen pharmacodynamics and pharmacokinetics in calves

A tissue cage model of inflammation in calves was used to determine the pharmacokinetic and pharmacodynamic properties of individual carprofen enantiomers, following the administration of the racemate. RS(±) carprofen was administered subcutaneously both alone and in combination with intramuscularly administered oxytetracycline in a four-period crossover study. Oxytetracycline did not influence the pharmacokinetics of R(-) and S(+) carprofen enantiomers, except for a lower maximum concentration (Cmax ) of S(+) carprofen in serum after co-administration with oxytetracycline. S(+) enantiomer means for area under the serum concentration-time curve (AUC0-96 h were 136.9 and 128.3 μg·h/mL and means for the terminal half-life (T(1/2) k10 ) were = 12.9 and 17.3 h for carprofen alone and in combination with oxytetracycline, respectively. S(+) carprofen AUC0-96 h in both carprofen treatments and T(1/2) k10 for carprofen alone were lower (P < 0.05) than R(-) carprofen values, indicating a small degree of enantioselectivity in the disposition of the enantiomers. Carprofen inhibition of serum thromboxane B2 ex vivo was small and significant only at a few sampling times, whereas in vivo exudate prostaglandin (PG)E2 synthesis inhibition was greater and achieved overall significance between 36 and 72 h (P < 0.05). Inhibition of PGE2 correlated with mean time to achieve maximum concentrations in exudate of 54 and 42 h for both carprofen treatments for R(-) and S(+) enantiomers, respectively. Carprofen reduction of zymosan-induced intradermal swelling was not statistically significant. These data provide a basis for the rational use of carprofen with oxytetracycline in calves and indicate that no alteration to carprofen dosage is required when the drugs are co-administered.

Reduction in cancer risk by selective and nonselective cyclooxygenase-2 (COX-2) inhibitors

We conducted a series of epidemiologic studies to evaluate the chemopreventive effects of aspirin, ibuprofen, and selective cyxlooxygenase-2 (COX-2) inhibitors (coxibs) against cancers of the breast, colon, prostate, and lung. Composite results across all four cancer sites revealed that regular intake of 325 mg aspirin, 200 mg ibuprofen, or standard dosages of coxibs (200 mg celecoxib or 25 mg rofecoxib) produced risk reductions of 49%, 59%, and 64%, respectively. Use of coxibs for at least 2 years was associated with risk reductions of 71%, 70%, 55%, and 60% for breast cancer, colon cancer, prostate cancer and lung cancer, respectively. Effects of ibuprofen were similar to selective coxibs, and slightly stronger than aspirin. These observed effects are consistent with the relative COX-2 selectivity of ibuprofen, coxibs, and aspirin. Acetaminophen, an analgesic without COX-2 activity, had no effect. Overexpression of COX-2 and increased prostaglandin biosynthesis correlates with carcinogenesis and metastasis at most anatomic sites. These results indicate that regular intake of nonselective or selective COX-2 inhibiting agents protects against the development of major forms of cancer.

Drug repurposing: far beyond new targets for old drugs

Repurposing drugs requires finding novel therapeutic indications compared to the ones for which they were already approved. This is an increasingly utilized strategy for finding novel medicines, one that capitalizes on previous investments while derisking clinical activities. This approach is of interest primarily because we continue to face significant gaps in the drug-target interactions matrix and to accumulate safety and efficacy data during clinical studies. Collecting and making publicly available as much data as possible on the target profile of drugs offer opportunities for drug repurposing, but may limit the commercial applications by patent applications. Certain clinical applications may be more feasible for repurposing than others because of marked differences in side effect tolerance. Other factors that ought to be considered when assessing drug repurposing opportunities include relevance to the disease in question and the intellectual property landscape. These activities go far beyond the identification of new targets for old drugs.

Bioavailability and pharmacokinetics of oral meloxicam in llamas

Background

South American camelids in the United States have rapidly developed into an important agricultural industry in need of veterinary services. Pain management is challenging in camelids because there are no drugs currently approved by the U.S. Food and Drug Administration for use in these species. Dosage regimens used for many therapeutic drugs have been extrapolated from other ruminants; however, the pharmacokinetics, in camelids, may differ from those of other species. Studies investigating the pharmacokinetics of cyclooxygenase-2 (COX-2) selective non-steroidal anti-inflammatory drugs in camelids are deficient in the published literature. Six adult llamas (121- 168 kg) were administered either a 1 mg/kg dose of oral or a 0.5 mg/kg dose of IV meloxicam in a randomized cross-over design with an 11 day washout period between treatments. Plasma samples collected up to 96 hours post-administration were analyzed by high pressure liquid chromatography and mass spectrometry detection (HPLC-MS) followed by non-compartmental pharmacokinetic analysis.

Results

A mean peak plasma concentration (C_MAX) of 1.314 μg/mL (Range: 0.826 – 1.776 μg/mL) was recorded at 21.4 hours (Range: 12.0 – 24.0 hours) with a half-life (T ½ λ_z) of 22.7 hours (Range: 18.0 – 30.8 hours) after oral meloxicam administration. In comparison, a half-life (T ½ λ_z) of 17.4 hours (Range: 16.2 – 20.7 hours) was demonstrated with IV meloxicam administration. The oral bioavailability (F) of meloxicam (dose normalized) was 76% (Range: 48 – 92%). No adverse effects associated with either treatment modality were observed in the llamas.

Conclusions

The mean bioavailability (F) of oral meloxicam was 76% indicating a high degree of gastrointestinal absorption. Plasma meloxicam concentrations >0.2 μg/mL were maintained for up to 72 h after oral administration; >0.2 μg/mL is considered to be the concentration of meloxicam required for analgesic effects in other species such as the horse. These data suggest that a single dosage of oral meloxicam at 1 mg/kg could potentially maintain therapeutic concentrations in plasma for up to 3 days in adult llamas.

Potency and selectivity of carprofen enantiomers for inhibition of bovine cyclooxygenase in whole blood assays

Whole blood in vitro assays were used to determine the potency and selectivity of carprofen enantiomers for inhibition of the isoforms of cyclooxygenase (COX), COX-1 and COX-2, in the calf. S(+)-carprofen possessed preferential activity for COX-2 inhibition but, because the slopes of inhibition curves differed, the COX-1:COX-2 inhibition ratio decreased from 9.04:1 for inhibitory concentration (IC)10 to 1.84:1 for IC95. R(-) carprofen inhibited COX-2 preferentially only for low inhibition of the COX isoforms (IC10 COX-1:COX-2=6.63:1), whereas inhibition was preferential for COX-1 for a high level of inhibition (IC95 COX-1:COX-2=0.20:1). S(+) carprofen was the more potent inhibitor of COX isoforms; potency ratios S(+):R(-) carprofen were 11.6:1 for IC10 and 218:1 for IC90. Based on serum concentrations of carprofen enantiomers obtained after administration of a therapeutic dose of 1.4 mg/kg to calves subcutaneously, S(+)-carprofen concentrations exceeded the in vitro IC80 COX-2 value for 32 h and the IC20 for COX-1 for 33 h. The findings are discussed in relation to efficacy and safety of carprofen in calves.

Preclinical predictors of anticancer drug efficacy: critical assessment with emphasis on whether nanomolar potency should be required of candidate agents

In the current paradigm of anticancer drug development, candidate compounds are evaluated by testing their in vitro potency against molecular targets relevant to carcinogenesis, their effect on cultured cancer cells, and their ability to inhibit cancer growth in animal models. We discuss the key assumptions inherent in these approaches. In recent years, great emphasis has been placed on selecting for development compounds with nanomolar in vitro potency, expecting that they will be efficacious and safer based on the assumption that they can be used at lower doses ("the nanomolar rule"). However, this rule ignores critical parameters affecting efficacy and toxicity such as physiochemical and absorption, distribution, metabolism and excretion properties, off-target effects, and multitargeting activities. Thus, uncritical application of the nanomolar rule may reject efficacious compounds or select ineffective or toxic compounds. We present examples of efficacious chemotherapeutic (alkylating agents, hormonal agents, antimetabolites, thalidomide, and valproic acid) and chemopreventive (aspirin and sulindac) agents having millimolar potency and compounds with nanomolar potency (cyclooxygenase-2 inhibitors) that, nevertheless, failed or proved to be unsafe. The effect of candidate drugs on animal models of cancer is a better predictor of human drug efficacy; particularly useful are tumor xenografts. Given the cost of failure at clinical stages, it is imperative to keep in mind the limitations of the nanomolar rule and use relevant in vivo models early in drug discovery to prioritize candidates. Although in vivo models will continue having a major role in cancer drug development, more robust approaches that combine high predictive ability with simplicity and low cost should be developed.

Epigenetic deregulation of the COX pathway in cancer

Inflammation is a major cause of cancer and may condition its progression. The deregulation of the cyclooxygenase (COX) pathway is implicated in several pathophysiological processes, including inflammation and cancer. Although, its targeting with nonsteroidal antiinflammatory drugs (NSAIDs) and COX-2 selective inhibitors has been investigated for years with promising results at both preventive and therapeutic levels, undesirable side effects and the limited understanding of the regulation and functionalities of the COX pathway compromise a more extensive application of these drugs. Epigenetics is bringing additional levels of complexity to the understanding of basic biological and pathological processes. The deregulation of signaling and biosynthetic pathways by epigenetic mechanisms may account for new molecular targets in cancer therapeutics. Genes of the COX pathway are seldom mutated in neoplastic cells, but a large proportion of them show aberrant expression in different types of cancer. A growing body of evidence indicates that epigenetic alterations play a critical role in the deregulation of the genes of the COX pathway. This review summarizes the current knowledge on the contribution of epigenetic processes to the deregulation of the COX pathway in cancer, getting insights into how these alterations may be relevant for the clinical management of patients.

Clinical pharmacology of nonsteroidal anti-inflammatory drugs in dogs

OBJECTIVES

To discuss the clinical pharmacology of currently licensed veterinary NSAIDs and to review gastrointestinal and renal adverse effects as well as drug-drug interactions that have been reported with these drugs. To review the use of NSAIDs in the peri-operative setting and their use in patients with osteoarthritis. To further review the reported effects of NSAIDs on canine articular cartilage and liver as well as the clinical relevance of a washout period.

DATABASES USED

PubMed, CAB abstracts and Google Scholar using dog, dogs, nonsteroidal anti-inflammatory drugs and NSAID(s) as keywords.

CONCLUSIONS

A good understanding of the mechanisms by which NSAIDs elicit their analgesic effect is essential in order to minimize adverse effects and drug-drug interactions. Cyclooxygenase (COX) is present in at least two active isoforms in the body and is the primary pharmacologic target of NSAIDs. Inhibition of COX is associated with the analgesic effects of NSAIDs. COX is present in the gastrointestinal tract and kidneys, along with other areas of the body, and is also the likely reason for many adverse effects including gastrointestinal and renal adverse effects. The newer veterinary approved NSAIDs have a lower frequency of gastrointestinal adverse effects in dogs compared to drugs such as aspirin, ketoprofen and flunixin, which may be due to differential effects on the COX isoforms. There are currently no published reports demonstrating that the newer NSAIDs are associated with fewer renal or hepatic adverse effects in dogs. NSAIDs remain the cornerstone of oral therapy for osteoarthritis unless contraindicated by intolerance, concurrent therapies or underlying medical conditions. NSAIDs are also effective and frequently used for the management of post-operative pain.

Structure-activity relationship of nonacidic quinazolinone inhibitors of human microsomal prostaglandin synthase 1 (mPGES 1)

Microsomal prostaglandin E synthase 1 (mPGES-1) is a key enzyme of the arachidonic acid cascade. Its product PGE(2) plays an important role in various inflammatory processes, pain, fever, and cancer. Selective inhibition of mPGES-1 might be a promising step to avoid cyclooxygenase-related effects of NSAIDs. We studied a class of quinazolinone derivatives of the lead structure FR20 for their effects on the isolated human and murine enzymes, human HeLa cells, and in various settings of the whole blood assay. Novel compounds with direct enzyme inhibiting activity in the submicromolar range (IC(50): 0.13-0.37 μM) were designed using a bioisosteric replacement strategy and proved to be effective in both cells and human whole blood. Furthermore, pharmacological profiling of toxicity and eicosanoid screening with LC/MS-MS was applied to characterize this new class of mPGES-1 inhibitors.

Small bowel injury induced by selective cyclooxygenase-2 inhibitors: a prospective, double-blind, randomized clinical trial comparing celecoxib and meloxicam

BACKGROUND

Selective cyclooxygenase (COX)-2 inhibitors are less harmful to the small bowel mucosa than non-selective anti-inflammatory drugs. We aimed to compare the severity of small bowel mucosal injury in healthy volunteers induced by two selective COX-2 inhibitors, celecoxib and meloxicam, in a randomized, double-blind trial, using capsule endoscopy (CE).

METHODS

Twenty-nine healthy subjects were randomized to take either celecoxib (200 mg twice daily) or meloxicam (10 mg once daily) for 2 weeks. The incidence and the number of small bowel mucosal injuries (bleeding, ulcers, and erosions) observed by CE were compared between the two groups.

RESULTS

The overall incidence of small bowel mucosal injury was not different between the celecoxib group (6 of 14 subjects, 42.9%) and the meloxicam group (4 of 15 subjects, 26.7%, P = 0.45). In subjects with positive CE findings, the number of ulcers was greater in the meloxicam group than in the celecoxib group (P = 0.02), while such a trend was not found with regard to erosions (P = 0.52). The distribution of mucosal lesions within the small bowel was similar in the two groups.

CONCLUSIONS

Selective COX-2 inhibitors are not completely safe for the small bowel. The mucosal lesions may be less severe with celecoxib than with meloxicam.

Insights into the effects of diclofenac and other non-steroidal anti-inflammatory agents on ion channels

OBJECTIVES

Diclofenac and other non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in the treatment of inflammation and pain. Most effects of NSAIDs are attributed to the inhibition of cyclooxygenases (COX). However, many NSAIDs may have other effects not related to COX, including the modulation of various ion channels. The clinical implications of the effects on channels are not fully understood. This review outlines the effects of NSAIDs, with special attention to diclofenac, on ion channels and highlights the possible underlying mechanisms.

KEY FINDINGS

NSAIDs have effects on channels such as inhibition, activation or changes in expression patterns. The channels affected include voltage-gated Na(+) , Ca(2+) , or K(+) channels, ligand-gated K(+) channels, transient receptor potential and other cation channels as well as chloride channels in several types of cells. The mechanisms of drug actions not related to COX inhibition may involve drug-channel interactions, interference with the generation of second messengers, changes in channel expression, or synergistic/antagonist interactions with other channel modulators.

SUMMARY

The effects on ion channels may account for novel therapeutic actions of NSAIDs or for adverse effects. Among the NSAIDs, diclofenac may serve as a template for developing new channel modulators and as a tool for investigating the actions of other drugs.

Effects of ibuprofen treatment on the developing preterm baboon kidney

Preterm neonates are commonly exposed postnatally to pharmacological treatments for a patent ductus arteriosus. Exposure of the developing kidney to nephrotoxic medications may adversely impact renal development. This study aimed to determine the effect of early postnatal ibuprofen treatment, both alone and in combination with a nitric oxide synthase inhibitor (NOSi), on renal development and morphology. Baboon neonates were delivered prematurely at 125-day (125d) gestation (term = 185d) and were euthanized at birth or postnatal day 6. Neonates were divided into four groups: 125d gestational controls (n = 8), Untreated (n = 8), Ibuprofen (n = 6), and ibuprofen (Ibu)+NOSi (n = 4). Animals in the Ibuprofen and Ibu+NOSi groups received five doses of ibuprofen, with the Ibuprofen+NOSi animals additionally administered a NOS inhibitor (N(G)-monomethyl-l-arginine). There was no difference among groups in body weight, kidney weight, or glomerular generation number. Nephrogenic zone width was significantly reduced in the Ibuprofen group (123.5 ± 7.4 μm) compared with the 125d gestational control (176.1 ± 6.9 μm) and Untreated animals (169.7 ± 78.8 μm). In the Ibu+NOSi group, nephrogenic zone width averaged 152.7 ± 3.9 μm, which was not significantly different from any other group. Morphologically abnormal glomeruli were present at a range of 0.0-22.9% in the Untreated group, 0.0-6.1% in the Ibuprofen group, and 0.0-1.4% in the Ibu+NOSi group. In conclusion, early postnatal ibuprofen exposure is associated with a reduced nephrogenic zone width, which may suggest the early cessation of nephrogenesis following treatment. Ultimately, this may impact the number of nephrons formed in the preterm kidney.

Effects of ibuprofen treatment on the developing preterm baboon kidney

Preterm neonates are commonly exposed postnatally to pharmacological treatments for a patent ductus arteriosus. Exposure of the developing kidney to nephrotoxic medications may adversely impact renal development. This study aimed to determine the effect of early postnatal ibuprofen treatment, both alone and in combination with a nitric oxide synthase inhibitor (NOSi), on renal development and morphology. Baboon neonates were delivered prematurely at 125-day (125d) gestation (term = 185d) and were euthanized at birth or postnatal day 6. Neonates were divided into four groups: 125d gestational controls (n = 8), Untreated (n = 8), Ibuprofen (n = 6), and ibuprofen (Ibu)+NOSi (n = 4). Animals in the Ibuprofen and Ibu+NOSi groups received five doses of ibuprofen, with the Ibuprofen+NOSi animals additionally administered a NOS inhibitor (N(G)-monomethyl-l-arginine). There was no difference among groups in body weight, kidney weight, or glomerular generation number. Nephrogenic zone width was significantly reduced in the Ibuprofen group (123.5 ± 7.4 μm) compared with the 125d gestational control (176.1 ± 6.9 μm) and Untreated animals (169.7 ± 78.8 μm). In the Ibu+NOSi group, nephrogenic zone width averaged 152.7 ± 3.9 μm, which was not significantly different from any other group. Morphologically abnormal glomeruli were present at a range of 0.0-22.9% in the Untreated group, 0.0-6.1% in the Ibuprofen group, and 0.0-1.4% in the Ibu+NOSi group. In conclusion, early postnatal ibuprofen exposure is associated with a reduced nephrogenic zone width, which may suggest the early cessation of nephrogenesis following treatment. Ultimately, this may impact the number of nephrons formed in the preterm kidney.

Transition of treatment for patients with extra-abdominal desmoid tumors: nagoya university modality

Treatment modalities for desmoid tumors have been changed because of the high recurrence rate, even after wide resection, and some cases experience spontaneous self-regression during clinical course. The treatment modality in our institutions before 2003 was surgical resection with wide surgical margin, however, meloxicam, which is a NSAID and a selective COX-2 inhibitor has been applied consecutively since 2003. We reviewed the previously reported outcomes of surgical and conservative treatment in our institutions. Among 30 patients receiving surgical treatment, 16 (53%) recurred. Younger age ( p < 0.05) was a significant poor factor. According to RECIST for meloxicam treatment, CR was in one, PR in 10, SD in eight, PD in one evaluated at 2011. Older age ( p < 0.01) was significantly associated with good outcome for meloxicam treatment. Results of the previous study indicated that surgical treatment alone could not control desmoid tumors, even with negative surgical margin. Considering the functional impairment resulting from surgery with negative surgical margin, a conservative and effective treatment modality with fewer complications is desired. Conservative treatment with meloxicam is a promising novel modality for patients with extra-abdominal desmoid tumors.

Quince (Cydonia oblonga Miller) peel polyphenols modulate LPS-induced inflammation in human THP-1-derived macrophages through NF-κB, p38MAPK and Akt inhibition

Chronic inflammation is a hallmark of several pathologies, such as rheumatoid arthritis, gastritis, inflammatory bowel disease, atherosclerosis and cancer. A wide range of anti-inflammatory chemicals have been used to treat such diseases while presenting high toxicity and numerous side effects. Here, we report the anti-inflammatory effect of a non-toxic, cost-effective natural agent, polyphenolic extract from the Tunisian quince Cydonia oblonga Miller. Lipopolysaccharide (LPS) treatment of human THP-1-derived macrophages induced the secretion of high levels of the pro-inflammatory cytokine TNF-α and the chemokine IL-8, which was inhibited by quince peel polyphenolic extract in a dose-dependent manner. Concomitantly, quince polyphenols enhanced the level of the anti-inflammatory cytokine IL-10 secreted by LPS-treated macrophages. We further demonstrated that the unexpected increase in IL-6 secretion that occurred when quince polyphenols were associated with LPS treatment was partially responsible for the polyphenols-mediated inhibition of TNF-α secretion. Biochemical analysis showed that quince polyphenols extract inhibited the LPS-mediated activation of three major cellular pro-inflammatory effectors, nuclear factor-kappa B (NF-κB), p38MAPK and Akt. Overall, our data indicate that quince peel polyphenolic extract induces a potent anti-inflammatory effect that may prove useful for the treatment of inflammatory diseases and that a quince-rich regimen may help to prevent and improve the treatment of such diseases.

Do nonsteroidal anti-inflammatory drugs affect bone healing? A critical analysis

Nonsteroidal anti-inflammatory drugs (NSAIDs) play an essential part in our approach to control pain in the posttraumatic setting. Over the last decades, several studies suggested that NSAIDs interfere with bone healing while others contradict these findings. Although their analgesic potency is well proven, clinicians remain puzzled over the potential safety issues. We have systematically reviewed the available literature, analyzing and presenting the available in vitro animal and clinical studies on this field. Our comprehensive review reveals the great diversity of the presented data in all groups of studies. Animal and in vitro studies present so conflicting data that even studies with identical parameters have opposing results. Basic science research defining the exact mechanism with which NSAIDs could interfere with bone cells and also the conduction of well-randomized prospective clinical trials are warranted. In the absence of robust clinical or scientific evidence, clinicians should treat NSAIDs as a risk factor for bone healing impairment, and their administration should be avoided in high-risk patients.

The effects of cyclooxygenase inhibitors on the brain inflammatory response following traumatic brain injury in rats

OBJECTIVES

Cytokines such as IL-1β are involved in inflammatory responses. This study evaluated the role of two different kinds of drugs (ibuprofen and celecoxib) on brain IL-10 and IL-1β after traumatic brain injury (TBI) in male rats.

MATERIALS AND METHODS

Rats were assigned into 6 groups: intact, sham, TBI, and treated rats with vehicle, celecoxib or iboprophen. Cytokine concentrations were quantified by ELISA kits.

RESULTS

Groups showed no significant difference in brain IL-10 either after TBI induction or after treatment with ibuprofen or celecoxib. Serum IL-10 in vehicle or ibuprofen treated animals was lower than in sham groups (P< 0.01). Brain IL-1β decreased after treatment by ibuprofen or celecoxib (P< 0.001). There was no statistical difference in serum IL-1β in TBI and intact. Serum IL-1β significantly decreased in rats that received celecoxib compared to TBI group (P< 0.01).

CONCLUSION

Based on our study IL-1β can decrease through both cyclooxygenase 1 (COX-1) and COX-2 pathway but serum IL-1β can decrease only by COX-2 pathway.