Comparative inhibitory activity of etoricoxib, celecoxib, and diclofenac on COX-2 versus COX-1 in healthy subjects

Effects of acute selective cyclooxygenase-2 inhibition on skeletal muscle microvascular oxygenation and exercise tolerance

The cyclooxygenase (COX) pathway regulates vascular tone and, therefore, local O2 delivery-utilization matching. The two main isoforms, COX-1 and COX-2, may promote opposing effects on contracting muscle O2 transport in health by inducing vasoconstriction and vasodilatation, respectively. Whether COX-2 and its main vasodilatory product (prostacyclin, PGI2) modulate microvascular O2 transport to skeletal muscle and thus exercise tolerance is unknown. We tested the hypothesis that acute selective COX-2 inhibition (SC2I) would impair cardiorespiratory and skeletal muscle microvascular responses from rest to exercise, thereby reducing exercise tolerance in healthy adults. Twelve individuals participated in a randomized, double-blind, crossover study to receive SC2I (200 mg celecoxib) or placebo (control, CON). Moderate and severe intensity cycling were performed with measurements of heart rate, arterial blood pressure, pulmonary oxygen uptake (V ̇ O 2 ${\dot V_{{{\mathrm{O}}_2}}}$ ), leg muscle microvascular oxygenation (S t O 2 ${S_{{\mathrm{t}}{{\mathrm{O}}_2}}}$ ; near-infrared spectroscopy) and time to exhaustion. Leg muscleS t O 2 ${S_{{\mathrm{t}}{{\mathrm{O}}_2}}}$ was also assessed during cuff occlusion protocols. SC2I decreased the plasma concentration of the stable PGI2 metabolite 6-keto prostaglandin F1α (CON: 203 (54) pg/mL; SC2I: 108 (54) pg/mL; P = 0.002). There was no difference in exercise tolerance (CON: 278 (55) s; SC2I: 298 (75) s), arterial blood pressure, heart rate, pulmonaryV ̇ O 2 ${\dot V_{{{\mathrm{O}}_2}}}$ or leg muscleS t O 2 ${S_{{\mathrm{t}}{{\mathrm{O}}_2}}}$ from rest to moderate or severe exercise between conditions (P > 0.05 for all). Moreover, there was no significant difference inS t O 2 ${S_{{\mathrm{t}}{{\mathrm{O}}_2}}}$ during cuff occlusion protocols between conditions. Contrary to our hypothesis, these data indicate that COX-2 is not obligatory for the regulation of skeletal muscle microvascular oxygenation at rest or during moderate or severe intensity exercise, and therefore does not modulate exercise tolerance in healthy adults.

Algerian Prickly Pear Seed By-Products: Fatty Acids Composition, Antioxidant, Enzyme Inhibitory Activities towards Tyrosinase, Urease, α-Amylase, and Cholinesterase, along with the Ability to Protect from Thermal Protein Denaturation

Prickly pear seed is a source of the most expensive oil in the world, which is rich in vitamins and polyunsaturated fatty acids. Its extraction generates a large quantity of press cake. These two by-products need to be valued. The current study aimed to assess the fatty acid composition of oil and the phytochemical composition of press cake. In addition, the antioxidant and the inhibition of thermal protein denaturation effects of both Algerian seed by-products were evaluated with their inhibitory action against the activities of urease, tyrosinase, α-amylase, and cholinesterase enzymes. The GC MS analysis result revealed the richness of our oil in linoleic (74%) and palmitic (13%) acids methyl esters, respectively. The chemical composition of press cake was characterized by a high value of dry matter (94.94 ± 0.05%), especially the carbohydrates (85.13 ± 0.94%). The results of antioxidant activity presented by IC50 and A0.5 ranged from 7.51 ± 0.03 to 88.10 ± 0.92 µg/mL. Furthermore, the IC50 values were 40.19 ± 1.21 and 61.18 ± 0.03 µg/mL in thermal protein denaturation assay, and ranging from 22.97 ± 0.72 to 385.99 ± 0.27 µg/mL for the inhibition of enzymatic activities. These results indicate that the studied oil can be one of the strongest oils for its impressive effects and also encourage us to reuse its press cake in feed livestock.

Recent progress in adverse events of carboxylic acid non-steroidal anti-inflammatory drugs (CBA-NSAIDs) and their association with the metabolism: the consequences on mitochondrial dysfunction and oxidative stress, and prevention with natural plant extracts

INTRODUCTION

Carboxylic acid non-steroidal anti-inflammatory drugs (CBA-NSAIDs) are extensively used worldwide due to their antipyretic, analgesic, and anti-inflammatory effects. CBA-NSAIDs have reasonable margin of safety at therapeutic doses, and in the current climate, do not possess addiction potential like opioid drugs. Studies have revealed that various adverse events of CBA-NSAIDs are related mitochondrial dysfunction and oxidative stress.

AREAS COVERED

This review article summarizes adverse events induced by CBA-NSAIDs, mechanisms of mitochondrial damage, oxidative stress, and metabolic interactions. Meanwhile, this review discusses the treatment and prevention of CBA-NSAIDs damage by natural plant extracts based on antioxidant effects.

EXPERT OPINION

CBA-NSAIDs can induce reactive oxygen species (ROS) production, mediate DNA, protein and lipid damage, lead to imbalance of cell antioxidant status, change of mitochondrial membrane potential, activate oxidative stress signal pathway, thus leading to oxidative stress and cell damage. Adverse events caused by CBA-NSAIDs often exhibit dose and time dependence. In order to avoid adverse events caused by CBA-NSAIDs, it is necessary to provide detailed patient consultation and eliminate influencing factors. Moreover, constructive research studies on the organ-specific toxicity and mechanism of natural plant extracts in preventing and treating metabolic abnormalities of CBA-NSAIDs, will provide important value for warning and guidance for use of CBA-NSAIDs.

Water dynamics on the structural properties of some NSAID's with leucine in the picosecond region using time domain spectroscopy

Concentration-dependent dielectric response for non-steroidal anti-inflammatory drugs (NSAIDs): Aceclofenac (ACF) and Diclofenac (DCF) in the aqueous leucine solution have been reported at different concentrations and temperatures (298.15 K to 283.15 K). The time domain reflectometry technique in the frequency region of 1 GHz to 30 GHz was used for the present study. Complex permittivity (ε*), static dielectric constant (ε), dielectric relaxation time (τ), dipole moment (μ) and Kirkwood correlation factor (g) have been calculated and discussed in terms of the molecular interaction of water and the used drugs. To give more insights into the structural dynamics of drug-induced amino acids, the study includes molar enthalpy of activation (ΔH), entropy of activation (ΔS), and free energy of activation (ΔF). The overall study concludes that the drug (DCF) having a potent inhibitor of cyclooxygenase found a higher static dielectric constant (ε0) than that of the drug (ACF) having more carbon (C), hydrogen (H), and oxygen (O) in the chain, which is more efficient in controlling pain.Communicated by Ramaswamy H. Sarma.

Pharmacological hypotheses: Is acetaminophen selective in its cyclooxygenase inhibition?

The precise mechanistic action of acetaminophen (ACT; paracetamol) remains debated. ACT's analgesic and antipyretic actions are attributed to cyclooxygenase (COX) inhibition preventing prostaglandin (PG) synthesis. Two COX isoforms (COX1/2) share 60% sequence structure, yet their functions vary. COX variants have been sequenced among various mammalian species including humans. A COX1 splice variant (often termed COX3) is purported by some as the elusive target of ACT's mechanism of action. Yet a physiologically functional COX3 isoform has not been sequenced in humans, refuting these claims. ACT may selectively inhibit COX2, with evidence of a 4.4-fold greater COX2 inhibition than COX1. However, this is markedly lower than other available selective COX2 inhibitors (up to 433-fold) and tempered by proof of potent COX1 inhibition within intact cells when peroxide tone is low. COX isoform inhibition by ACT may depend on subtle in vivo physiological variations specific to ACT. In vivo ACT efficacy is reliant on intact cells and low peroxide tone while the arachidonic acid concentration state can dictate the COX isoform preferred for PG synthesis. ACT is an effective antipyretic (COX2 preference for PG synthesis) and can reduce afebrile core temperature (likely COX1 preference for PG synthesis). Thus, we suggest with specificity to human in vivo physiology that ACT: (i) does not act on a third COX isoform; (ii) is not selective in its COX inhibition; and (iii) inhibition of COX isoforms are determined by subtle and nuanced physiological variations. Robust research designs are required in humans to objectively confirm these hypotheses.

Effect of diclofenac on semen quality: A review

Diclofenac is an effective nonsteroidal anti-inflammatory drug and one of the most prescribed medicines worldwide. So far, there are many published articles that directly link between diclofenac and semen quality; however, hitherto, there is no collective review or comprehensive discussion that reveal such imperative link. Therefore, this work reviews and judges the association between diclofenac administration and semen quality, henceforth male infertility. As a tool to accomplish this scientific input, Scopus, Embase and PubMed databases have been searched for all original articles using the keywords "diclofenac" versus "semen" and "sperm" since August 1987 through November 2020. In summary, diclofenac appears to induce negative effects on both qualitative and quantitative measures of sperm; however, this conclusion requires confirmation by human studies. The detected negative effects of diclofenac on semen quality measures may be owed to reduced levels of gonadal hormones, decreased antioxidant defence mechanism, increased oxidative stress, altered concentrations of nitric oxide that are required to maintain normal sperm physiology and reduced synthesis of prostaglandins.

Rationale and evidence for the incorporation of heparin into the diclofenac epolamine medicated plaster

OBJECTIVE

The nonsteroidal anti-inflammatory drug (NSAID) diclofenac epolamine (DHEP) formulated as a topical patch has demonstrated efficacy and safety in the localized treatment of acute pain from minor strains, sprains and contusions, and for epicondylitis and knee osteoarthritis. The glycosaminoglycan heparin enhances the activity of topical NSAIDs formulated as a medicated plaster, even in the absence of any significant release of heparin. Therefore, DHEP plus, a new formulation of the DHEP medicated plaster containing a small amount of heparin sodium as excipient, has been developed.

METHODS

We reviewed the pivotal and supportive studies of the clinical development program of the new patch and evaluated the role of heparin as an enhancer in the treatment of localized pain/inflammation of musculoskeletal structures, associated with post-traumatic and/or rheumatic conditions.

RESULTS

The data was consistent with the concept that heparin increased the clinical activity of the DHEP plus medicated plaster versus the reference DHEP medicated plaster through improved bioavailability due to enhanced movement of diclofenac from the plaster. Both DHEP formulations have the same dissolution profile, indicating that heparin does not change the physical and chemical characteristics of the plaster. Permeation testing showed that heparin is not released from the DHEP plus medicated plaster. Efficacy studies showed that the DHEP plus medicated plaster was significantly more effective in reducing pain than the reference marketed DHEP medicated plaster.

CONCLUSIONS

The benefit/risk assessment of DHEP plus 180 mg medicated plaster is favorable, with a safety profile equal to placebo and improved efficacy over the reference marketed DHEP medicated plaster.

Effects of Selective Versus Non-Selective COX-2 Inhibition on Experimental Periodontitis

In the present study we compared the effects of the selective COX-2 inhibitor etoricoxib with those of the classical non-selective NSAID diclofenac on the inflammatory process and alveolar bone loss in an experimental model of periodontitis in rats. Ninety male Holtzman rats (250 g) were randomly sorted into four experimental groups: Sham+CMC and Ligature+CMC (control) groups which received 0.5% carboxymethylcellulose sodium (CMC) solution; Ligature+Diclofenac and Ligature+Etoricoxib groups which received Potassium Diclofenac and Etoricoxib, respectively, suspended in 0.5% CMC (10 mg/kg/day). At 7, 14 and 21 days after placing ligatures in the cervical region of both the lower right and left first molars, the animals were euthanized. At the end of each period, the mandibles were collected for radiographic examination of alveolar bone loss. In addition, alveolar bone and periodontal ligament tissue samples were collected for COX-2 expression analysis and gingival tissues were collected for measurement of PGE2 contents. Animals with ligature-induced periodontal disease showed significant increased COX-2 gene expression at days 7, 14 and 21 (p<0.05) on alveolar bone and periodontal ligament. However, both treatments resulted in significantly reduced alveolar bone loss when compared to the untreated Ligature group (p<0.05), with no statistical difference between Etoricoxib and Diclofenac Potassium groups. This study shows that both drugs were able to reduce alveolar bone loss after periodontal disease induction.

Are All Oral COX-2 Selective Inhibitors the Same? A Consideration of Celecoxib, Etoricoxib, and Diclofenac

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been widely used for the treatment of arthritic conditions. Drugs in this heterogeneous class alleviate pain and inflammation by inhibiting cyclooxygenase-2 (COX-2). Cyclooxygenase-1 (COX-1) inhibition has traditionally been associated with increased gastrointestinal (GI) harm, whereas increased COX-2 selectivity has more recently become associated with greater risk of cardiovascular (CV) harm. When the entirety of data is considered, NSAIDs can be seen to exhibit a range of COX isoform selectivity, with all oral NSAIDs appearing to be associated with an increase in CV events. This review focuses on a comparison of the efficacy and the GI and CV safety profiles of three commonly used NSAIDs-celecoxib, etoricoxib, and diclofenac-using direct comparisons where available. While all three treatments are shown to have comparable efficacy, there are differences in their safety profiles. Both celecoxib and etoricoxib are associated with less GI harm than diclofenac despite the similarity of its COX-2 selectivity to celecoxib. Each of the three medicines under consideration is associated with a similar overall risk of CV events (fatal and nonfatal heart attacks and strokes). However, there are consistent differences in effects on blood pressure (BP), reported both from trials using ambulatory techniques and from meta-analyses of randomized trials, reporting investigator determined effects, with etoricoxib being associated with a greater propensity to destabilize BP control than either diclofenac or celecoxib.

Adjunctive use of celecoxib with anti-tuberculosis drugs: evaluation in a whole-blood bactericidal activity model

COX-2 inhibition may be of benefit in the treatment of tuberculosis (TB) through a number of pathways including efflux pump inhibition (increasing intracellular TB drug levels) and diverse effects on inflammation and the immune response. We investigated celecoxib (a COX-2 inhibitor) alone and with standard anti-tuberculosis drugs in the whole-blood bactericidal activity (WBA) model. Healthy volunteers took a single dose of celecoxib (400 mg), followed (after 1 week) by a single dose of either rifampicin (10 mg/kg) or pyrazinamide (25 mg/kg), followed (after 2 or 7 days respectively) by the same anti-tuberculosis drug with celecoxib. WBA was measured at intervals until 8 hours post-dose (by inoculating blood samples with Mycobacterium tuberculosis and estimating the change in bacterial colony forming units after 72 hours incubation). Celecoxib had no activity alone in the WBA assay (cumulative WBA over 8 hours post-dose: 0.03 ± 0.01ΔlogCFU, p = 1.00 versus zero). Celecoxib did not increase cumulative WBA of standard TB drugs (mean cumulative WBA −0.10 ± 0.13ΔlogCFU versus −0.10 ± 0.12ΔlogCFU for TB drugs alone versus TB drugs and celecoxib; mean difference −0.01, 95% CI −0.02 to 0.00; p = 0.16). The lack of benefit of celecoxib suggests that efflux pump inhibition or eicosanoid pathway-related responses are of limited importance in mycobacterial killing in the WBA assay.

Diclofenac but not celecoxib improves endothelial function in rheumatoid arthritis: A study in adjuvant-induced arthritis

BACKGROUND AND AIMS

We aimed at investigating the effect of celecoxib (COX-2 selective inhibitor) and diclofenac (non-selective COX inhibitor) on endothelial function, and at identifying the underlying mechanisms in adjuvant-induced arthritis (AIA).

METHODS

At the first signs of AIA, diclofenac (5 mg/kg twice a day, i.p), celecoxib (3 mg/kg/day, i.p) or saline (Vehicle) was administered for 3 weeks. Endothelial function was studied in aortic rings relaxed with acetylcholine (Ach) with or without inhibitors of NOS, arginase, EDHF and superoxide anions (O₂^-°) production. Aortic expression of eNOS, Ser1177-phospho-eNOS, COX-2, arginase-2, p22^phox and p47^phox was evaluated by Western blotting analysis. Arthritis scores, blood pressure, glycaemia and serum ADMA levels were measured.

RESULTS

Diclofenac and celecoxib significantly reduced arthritis score to the same extent (p<0.05). As compared to vehicle-treated AIA, celecoxib did not change whereas diclofenac improved endothelial function (p<0.05) through increased EDHF production, decreased arginase activity and expression, decreased superoxide anions production and expression of p22^phox and p47^phox. Diclofenac but not celecoxib significantly enhanced blood pressure and serum ADMA levels. Glycaemia was unchanged by both treatments.

CONCLUSIONS

Our study reveals that the effect of NSAIDs on endothelial function cannot be extrapolated from their impact on arthritis severity and suggest that changes in blood pressure and plasma ADMA levels may not be useful to predict CV risk of NSAIDs in RA.

The Cardiovascular Pharmacology of Nonsteroidal Anti-Inflammatory Drugs

The principal molecular mechanisms underlying the cardiovascular (CV) and renal adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDs), such as myocardial infarction and hypertension, are understood in more detail than most side effects of drugs. Less is known, however, about differences in the CV safety profile between chemically distinct NSAIDs and their relative predisposition to complications. In review article, we discuss how heterogeneity in the pharmacokinetics and pharmacodynamics of distinct NSAIDs may be expected to affect their CV risk profile. We consider evidence afforded by studies in model systems, mechanistic clinical trials, a meta-analysis of randomized controlled trials, and two recent large clinical trials, Standard Care vs. Celecoxib Outcome Trial (SCOT) and Prospective Randomized Evaluation of Celecoxib Integrated Safety versus Ibuprofen or Naproxen (PRECISION), designed specifically to compare the CV safety of the cyclooxygenase-2-selective NSAID, celecoxib, with traditional NSAIDs. We conclude that SCOT and PRECISION have apparently not compared equipotent doses and have other limitations that bias them toward underestimation of the relative risk of celecoxib.

Pharmacokinetic and pharmacodynamic evaluation according to absorption differences in three formulations of ibuprofen

OBJECTIVE

Prostaglandin E₂ (PGE₂) synthesis is modulated by COX2. Changes in PGE₂ could be used to quantify the COX2 inhibition after ibuprofen administration. This study investigated the pharmacokinetic and pharmacodynamic relationships for COX2 inhibition according to three formulations of ibuprofen in healthy male subjects.

MATERIALS AND METHODS

A randomized, open-label, single-dose, three-treatment, six-sequence crossover study was performed in 36 healthy South Korean male volunteers. Enrolled subjects received the following three 200 mg ibuprofen formulations: ibuprofen arginine, solubilized ibuprofen capsule, and standard ibuprofen. Pharmacokinetic and pharmacodynamic blood samples were collected for 16 hours following treatment. For pharmacodynamic evaluations, lipopolysaccharide (LPS)-induced PGE₂ inhibition at each time point compared to predose was measured. Noncompartmental analysis was used for pharmacokinetic assessment, and time-weighted average inhibition (WAI) of PGE₂ was applied to the pharmacodynamic evaluation.

RESULTS

After a single oral dose of the ibuprofen formulations, the median times to maximum concentration were 0.42, 0.5, and 1.25 hours in ibuprofen arginine, solubilized ibuprofen capsule, and ibuprofen, respectively. The maximum observed plasma concentration was lower in ibuprofen, and the area under the plasma concentration-time curve was comparable among the three formulations. A significant difference was observed between fast-acting formulations and standard ibuprofen tablets for both maximum concentration and time taken to reach it. Individual formulations had an effect on PGE₂ WAI during the 8 hours following treatment, resulting in significantly lower WAI in standard ibuprofen: ibuprofen arginine 18.4%, solubilized ibuprofen capsule 18.4%, and standard ibuprofen 11.6%.

CONCLUSION

Rapid absorption and higher peak concentration were observed in ibuprofen arginine and the solubilized ibuprofen capsule. Additionally, fast-acting formulations had more predominant inhibitory activity on the COX2 enzyme.

Risk of perioperative bleeding related to highly selective cyclooxygenase-2 inhibitors: A systematic review and meta-analysis

BACKGROUND

Several literatures reported that highly selective cycloxygenase-2 inhibitors (COX-2 inhibitors) had no effect on platelet function. However, some experts suggested stopping all non-steroidal anti-inflammatory drugs (NSAIDs), including COX-2 inhibitors at least five elimination half-lives prior to surgery. We, therefore, systematically summarized the risk of clinical bleeding or platelet dysfunction in healthy or surgical subjects who received COX-2 inhibitors.

METHODS

Two electronic databases, MEDLINE and EMBASE, were searched for randomized, controlled studies published during 1980-December 2015. Additionally, manual search was performed to identify potential eligible studies. Intervention was perioperative use of any available COX-2 inhibitors in current practice (celecoxib, parecoxib, or etoricoxib), compared to non-selective NSAIDs, analgesics, or placebo. Two independent reviewers selected eligible studies, extracted the data, and assessed the quality of the included studies. The primary outcome was postoperative bleeding. All analyses were performed using RevMan-5.3.

RESULTS

Of 3900 abstracts reviewed, 35 studies met the inclusion criteria. The data from 16 out of 35 studies were used in this meta-analysis, and outcomes of other 19 remaining studies were descriptively summarized. COX-2 inhibitors did not significantly increase the risk of postoperative bleeding events (relative risk or RR = 0.92; 95% confidence interval or CI: 0.63-1.33; p = 0.65), intraoperative blood loss (mL) (weighted mean difference or WMD = -4.38; 95% CI: -14.69 to 5.92; p = 0.4), postoperative blood loss (mL) (WMD = -13.89; 95% CI: -30.24 to 2.47; p = 0.10), and 24-h postoperative hemoglobin loss (g/dL) (WMD = 0.47; 95% CI: -0.14 to 1.09; p = 0.13). Platelet function analyzer closure time (second) significantly decreased with the use of COX-2 inhibitors (WMD = -22.22; 95% CI: -44.03 to -0.41; p < 0.00001). In the 19 remaining studies, COX-2 inhibitors did not significantly increase risk of bleeding in both clinical and laboratory outcomes.

CONCLUSION

Highly selective COX-2 inhibitors did not significantly increase the risk of intraoperative, postoperative bleeding, or blood loss. They also had no significant effect on platelet function. Therefore, perioperative, single dose, or short course of COX-2 inhibitors can be safely used in individuals who are undergoing surgery.

Inhibition of prostacyclin and thromboxane biosynthesis in healthy volunteers by single and multiple doses of acetaminophen and indomethacin

This double-blind, randomized crossover study assessed the effect of acetaminophen (1000 mg every 8 hours) versus indomethacin (50 mg every 8 hours) versus placebo on cyclooxygenase enzymes (COX-1 and COX-2). Urinary excretion of 2,3-dinor-6-keto-PGF1α, (prostacyclin metabolite, PGI-M; COX-2 inhibition) and 11-dehydro thromboxane B2 (thromboxane metabolite, Tx-M; COX-1 inhibition) were measured after 1 dose and 5 days of dosing. Peak inhibition of urinary metabolite excretion across 8 hours following dosing was the primary end point. Mean PGI-M excretion was 33.7%, 55.9%, and 64.6% on day 1 and 49.4%, 65.1%, and 80.3% on day 5 (placebo, acetaminophen, and indomethacin, respectively). Acetaminophen and indomethacin inhibited PGI-M excretion following single and multiple doses (P = .004 vs placebo). PGI-M excretion inhibition after 1 dose was similar for indomethacin and acetaminophen, but significantly greater with indomethacin after multiple doses (P = .006). Mean Tx-M excretion was 16.2%, 45.2%, and 86.6% on day 1 and 46.2%, 58.4%, and 92.6% on day 5 (placebo, acetaminophen, and indomethacin, respectively). Tx-M excretion inhibition following 1 dose was reduced by acetaminophen (P ≤ .003). Indomethacin reduced Tx-M excretion significantly more than acetaminophen and placebo after single and multiple doses (P ≤ .001). Acetaminophen and indomethacin inhibited COX-1 and COX-2 following a single dose, but acetaminophen was a less potent COX-1 inhibitor than indomethacin.

Meloxicam prevents COX-2-mediated post-surgical inflammation but not pain following laparotomy in mice

BACKGROUND

Inflammation is thought to be a major contributor to post-surgical pain, so non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used analgesics. However, compared to rats, considerably less is known as to how successfully these prevent pain in mice.

METHODS

A fluorescent COX-2 selective probe was used for the first time to evaluate the post-surgical anti-inflammatory effects of meloxicam, and automated behaviour analyses (HomeCageScan; HCS), the Mouse Grimace Scale (MGS) and body weight changes to assess its pain-preventative properties. Groups of 8-9 BALB/c mice were subcutaneously injected with saline (0.3 mL) or meloxicam at (1, 5 or 20 mg/kg) 1 h before a 1.5-cm midline laparotomy. The probe or a control dye (2 mg/kg) was injected intravenously 3 h later. Imaging was used to quantify inflammation at 7, 24 and 48 h following surgery. HCS data and MGS scores were respectively obtained from video recordings and photographs before surgery and 24 h later.

RESULTS

Post-surgical inflammation was dose dependently reduced by meloxicam; with 5 or 20 mg/kg being most effective compared to saline. However, all mice lost weight, MGS scores increased and behavioural activity was reduced by surgery for at least 24 h with no perceivable beneficial effect of meloxicam on any of these potentially pain-associated changes.

CONCLUSIONS

Although meloxicam prevented inflammation, even large doses did not prevent post-laparotomy pain possibly arising due to a range of factors, including, but not limited to inflammation. MGS scoring can be applied by very naïve assessors and so should be effective for cage-side use.

Repurposing Drugs in Oncology (ReDO)-diclofenac as an anti-cancer agent

Diclofenac (DCF) is a well-known and widely used non-steroidal anti-inflammatory drug (NSAID), with a range of actions which are of interest in an oncological context. While there has long been an interest in the use of NSAIDs in chemoprevention, there is now emerging evidence that such drugs may have activity in a treatment setting. DCF, which is a potent inhibitor of COX-2 and prostaglandin E2 synthesis, displays a range of effects on the immune system, the angiogenic cascade, chemo- and radio-sensitivity and tumour metabolism. Both pre-clinical and clinical evidence of these effects, in multiple cancer types, is assessed and summarised and relevant mechanisms of action outlined. Based on this evidence the case is made for further clinical investigation of the anticancer effects of DCF, particularly in combination with other agents - with a range of possible multi-drug and multi-modality combinations outlined in the supplementary materials accompanying the main paper.

Topical diclofenac does not affect the antiplatelet properties of aspirin as compared to the intermediate effects of oral diclofenac: A prospective, randomized, complete crossover study

Nonsteroidal anti-inflammatory drugs (NSAIDs) adversely interact with aspirin, diminishing its antiplatelet effect and potentially placing patients at an increased risk for recurrent thrombotic events. This crossover study aimed to determine whether the topical NSAID diclofenac epolamine 1.3% patch or oral diclofenac 50 mg interfered with the antiplatelet effects of aspirin 325 mg. Twelve healthy men and women aged 18-50 were included. Participants were randomized into 5 treatment arms: aspirin, diclofenac potassium 50 mg, diclofenac patch, diclofenac potassium plus ASA 325 mg, and diclofenac patch plus aspirin. Platelet responsiveness was determined using whole-blood impedance aggregation (WBA) to collagen 1 μg/mL and arachidonic acid (AA) 0.5 mM and was sampled every 2 hours. No significant difference in platelet function was observed following the diclofenac patch and aspirin vs aspirin alone. Oral diclofenac produced a mixed effect with significant reduction in platelet inhibition at hour 2 and hour 8 following aspirin administration. Topical diclofenac does not significantly interfere with the antiplatelet effects of aspirin and may be a safer alternative to the oral formulation.

Celecoxib and Diclofenac Plus Omeprazole are Similarly Effective in the Treatment of Arthritis in Patients at High GI Risk in the CONDOR Trial

OBJECTIVE

Compare effectiveness of celecoxib versus diclofenac plus omeprazole in improving arthritis signs and symptoms in patients at high gastrointestinal (GI) risk who were enrolled in the CONDOR (Celecoxib vs Omeprazole and Diclofenac in Patients With Osteoarthritis and Rheumatoid Arthritis) trial.

METHODS

CONDOR was a 6-month, prospective, double-blind, triple-dummy, parallel-group, randomized, multicenter trial comparing celecoxib 200 mg twice daily versus diclofenac slow release (SR) 75 mg twice daily plus omeprazole 20 mg daily. Patients were Helicobacter pylori negative, had osteoarthritis (OA) or rheumatoid arthritis (RA), were aged ≥60 years, were with or without a history of gastroduodenal ulceration, or were ≥18 years with previous gastroduodenal ulceration. Patients' Global Assessment of Arthritis was determined at each study visit.

RESULTS

A total of 4484 patients were randomized to treatment (2238 celecoxib, 2246 diclofenac SR) and included in the intention-to-treat analyses. Least squares mean (LSM) (standard error [SE]) for Patients' Global Assessment of Arthritis was 3.219 (0.017) and 3.221 (0.017) at baseline for celecoxib and diclofenac SR (p=0.90). Improvement in both groups was similar in months 2, 4, and 6; at month 1 the LSM (SE) was 2.647 (0.017) and 2.586 (0.017) for celecoxib and diclofenac (p=0.0025). LSM difference (SE) from baseline to final visit demonstrated an improvement of 0.75 (0.02) in celecoxib-treated patients and 0.77 (0.02) in diclofenac SR-treated patients (p=0.42).

CONCLUSIONS

Celecoxib and diclofenac plus omeprazole were shown to have similar efficacy in patients with OA and/or RA at increased GI risk who were enrolled in the CONDOR trial.

TRIAL REGISTRY

Trial was registered under ClinicalTrials.gov identifier NCT00141102.

A diclofenac suppository-nabumetone combination therapy for arthritic pain relief and a monitoring method for the diclofenac binding capacity of HSA site II in rheumatoid arthritis

Diclofenac suppository, a non-steroidal anti-inflammatory drug (NSAID), is used widely in rheumatoid arthritis (RA) patients with severe arthritic pain. As the binding percentage of diclofenac to serum proteins is high, its free (unbound) concentration after rectal administration is low. To increase temporarily the free concentration of diclofenac and to enhance its analgesic effect by inhibiting the protein binding of diclofenac, the analgesic effect of diclofenac was examined before and after the start of an inhibitor administration to RA patients with insufficient control of arthritic pain, and the protein binding capacity of diclofenac was evaluated. Binding experiments were performed by ultrafiltration, and arthritic pain was recorded by the face scale. Free fractions of diazepam and diclofenac were augmented by increasing 6-methoxy-2-naphthylacetic acid (6-MNA; the active metabolite of the NSAID nabumetone) concentrations. The free fraction of diazepam increased after the start of nabumetone administration to RA patients, and arthritic pain relief was observed. These results suggest that 6-MNA has an inhibitory effect on the protein binding of diclofenac and the free fraction of diazepam can be used to evaluate the binding capacity of diclofenac. It is considered that diclofenac suppository-nabumetone combination therapy and the method for protein binding monitoring by diazepam can positively benefit RA patients with insufficient control of arthritic pain.

Increase of cyclooxygenase-2 inhibition with celecoxib combined with 5-FU enhances tumor cell apoptosis and antitumor efficacy in a subcutaneous implantation tumor model of human colon cancer

Background

The purpose of this study was to investigate the anti-tumor effect and explore the mechanisms of celecoxib (a selective cyclooxygenase-2 inhibitor) combined with 5-fluorouracil (5-FU) on the treatment of human colorectal cancer in a BALB/C nude mouse subcutaneous xenograft model.

Methods

Effects of celecoxib combined with 5-FU on the proliferation of xenograft carcinoma induced by HT-29 were investigated. The apoptotic cells were detected by electron microscope and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay. Immunohistochemistry and Western blot were used to estimate the expression of cytochrome C, caspase-3 and caspase-9.

Results

Compared with the control group, treatment groups showed significant inhibition of tumor growth. More apoptotic cells existed after treatment with celecoxib combined with 5-FU. Cytochrome C, caspase-3 and caspase-9 were increased in treated groups, and more obviously in the drug combination group. Cyclooxygenase-2 (COX-2) were decreased after treatment with celecoxib only or combined with 5-FU. And the combined group showed a greater decrease.

Conclusions

Celecoxib combined with 5-FU could inhibit the growth of tumors in vivo by inducing apoptosis and activation of the cytochrome C dependency apoptosis signal pathway. A decrease of COX-2 and an increase of cytochrome C, caspase-3 and caspase-9 may be involved in this process.

Etoricoxib and the treatment of ankylosing spondylitis

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line therapies in the management of patients with ankylosing spondylitis. This chronic inflammatory skeletal disorder, a subtype of spondyloarthritis, is characterized by inflammatory back pain and affects young adults causing important suffering and disability. Long-term use of conventional NSAIDs is associated with a risk of gastrointestinal complications. Etoricoxib is a specific cyclooxygenase 2 inhibitor with strong anti-inflammatory effects and a favorable pharmacokinetic profile for the management of inflammatory disorders. The drug has been associated with reduced severe gastrointestinal adverse events. However, the cardiovascular safety of cyclooxygenase 2 inhibitors has been debated.

AREAS COVERED

This review discusses etoricoxib in the treatment of ankylosing spondylitis. Literature searches were performed in PubMed, Web of Science, and the Cochrane library based on the terms "etoricoxib" and "ankylosing spondylitis" or "spondyloarthritis" as well as "safety" and "side-effects."

EXPERT OPINION

Etoricoxib is useful in the first-line management of ankylosing spondylitis patients. Its anti-inflammatory effects and relative protection against severe gastrointestinal side effects should be balanced with negative effects on the cardiovascular system and an overall subjective tolerance not better than that of conventional NSAIDs. Whether etoricoxib will also become a mainstay in the prevention of structural damage in ankylosing spondylitis is not yet clear.

Topical nonsteroidal anti-inflammatory drugs for the treatment of pain due to soft tissue injury: diclofenac epolamine topical patch

The objective of this article is to review published clinical data on diclofenac epolamine topical patch 1.3% (DETP) in the treatment of acute soft tissue injuries, such as strains, sprains, and contusions. Review of published literature on topical nonsteroidal anti-inflammatory drugs (NSAIDs), diclofenac, and DETP in patients with acute soft tissue injuries was included. Relevant literature was identified on MEDLINE using the search terms topical NSAIDs, diclofenac, diclofenac epolamine, acute pain, sports injury, soft tissue injury, strain, sprain, and contusion, and from citations in retrieved articles covering the years 1978-2008. Review of published, randomized clinical trials and meta-analyses shows that topical NSAIDs are significantly more effective than placebo in relieving acute pain; the pooled average relative benefit was 1.7 (95% confidence interval, 1.5-1.9). In a limited number of comparisons, topical and oral NSAIDs provided comparable pain relief, but the use of topical agents produced lower plasma drug concentrations and fewer systemic adverse events (AEs). The physical-chemical properties of diclofenac epolamine make it well suited for topical use. In patients with acute soft tissue injuries treated with DETP, clinical data report an analgesic benefit within hours of the first application, and significant pain relief relative to placebo within 3 days. Moreover, DETP displayed tolerability comparable with placebo; the most common AEs were pruritus and other application site reactions. Review of published literature suggests that DETP is generally safe and well tolerated, clinically efficacious, and a rational treatment option for patients experiencing acute pain associated with strains, sprains, and contusions, and other localized painful conditions.

Topical diclofenac epolamine patch 1.3% for treatment of acute pain caused by soft tissue injury

Acute pain caused by musculoskeletal disorders is very common and has a significant negative impact on quality-of-life and societal costs. Many types of acute pain have been managed with traditional oral non-steroidal anti-inflammatory drugs (NSAIDs) and selective cyclooxygenase-2 inhibitors (coxibs). Data from prospective, randomised controlled clinical trials and postmarketing surveillance indicate that use of oral traditional NSAIDs and coxibs is associated with an elevated risk of developing gastrointestinal, renovascular and/or cardiovascular adverse events (AEs). Increasing awareness of the AEs associated with NSAID therapy, including coxibs, has led many physicians and patients to reconsider use of these drugs and look for alternative treatment options. Treatment with NSAIDs via the topical route of administration has been shown to provide clinically effective analgesia at the site of application while minimising systemic absorption. The anti-inflammatory and analgesic potency of the traditional oral NSAID diclofenac, along with its physicochemical properties, makes it well suited for topical delivery. Several topical formulations of diclofenac have been developed. A topical patch containing diclofenac epolamine 1.3% (DETP, FLECTOR(®) Patch), approved for use in Europe in 1993, has recently been approved for use in the United States and is indicated for the treatment of acute pain caused by minor strains, sprains and contusions. In this article, we review the available clinical trial data for this product in the treatment of pain caused by soft tissue injury.

A histological investigation concerning the effects of diclofenac sodium to the lung in 4- and 20-week-old rats treated prenatally

OBJECTIVE

We aimed to investigate the possible postnatal effects on the lung tissues of the rat offspring treated with diclofenac sodium (DS) during pregnancy.

METHODS

After mating, pregnant female rats were separated into the control (n = 10) and DS (n = 10) groups. DS (1 mg/kg) was injected intraperitoneally (i.p) to the drug-treated group for the period of gestational days 5-19. Physiological saline (1 ml, i.p.) was given to the control groups. After birth, pups were separated into DS treatment groups (n = 24) and control group (n = 24). The DS and control group animals were anaesthetised with i.p. injection of urethane and their lungs were removed to prepare for histopathological evaluation.

RESULTS

Histological examination of the lung tissues of the 4- and 20-week-old rats revealed no significant differences between males and females in both the control and DS treated rats.

CONCLUSION

Because of the use of DS in the pregnant women further studies are needed in this field.

Emotion recollected in tranquility: lessons learned from the COX-2 saga

Nonsteroidal antinflammatory drugs (NSAIDs) inhibit prostaglandin formation by cyclooxygenases (COX) 1 and 2. NSAIDs selective for inhibition of COX-2 are less likely than traditional drugs to cause serious gastrointestinal adverse effects, but predispose to adverse cardiovascular events, such as heart failure, myocardial infarction, and stroke. Evidence from human pharmacology and genetics, genetically manipulated rodents, and other animal models and randomized trials indicates that this is consequent to suppression of COX-2-dependent cardioprotective prostagladins, particularly prostacyclin. Lessons drawn from how this saga unfolded are relevant to how we approach drug surveillance and regulation, integrate diversifed forms of information and might pursue a more personalized approach to drug efficacy and risk.

Absorption and distribution of etoricoxib in plasma, CSF, and wound tissue in patients following hip surgery--a pilot study

The perioperative administration of selective cyclooxygenase-2 (COX-2)-inhibitors to avoid postoperative pain is an attractive option: they show favorable gastro-intestinal tolerability, lack inhibition of blood coagulation, and carry a low risk of asthmatic attacks. The purpose of this study was to determine the cerebrospinal fluid (CSF), plasma, and tissue pharmacokinetics of orally administered etoricoxib and to compare it with effect data, i.e., COX-2-inhibition in patients after hip surgery. The study was performed in a blinded, randomized, parallel group design. A total of 12 adult patients were included who received 120 mg etoricoxib (n = 8) or placebo (n = 4) on day 1 post-surgery. Samples from plasma, CSF, and tissue exudates were collected over a period of 24 h post-dosing and analyzed for etoricoxib and prostaglandin E₂ (PGE₂) using liquid chromatography-tandem mass spectrometry and immuno-assay techniques. CSF area under the curve (AUC) [AUCs_(O–24h)] for etoricoxib amounted to about 5% of the total AUC in plasma (range: 2–7%). Individual CSF lag times with respect to (50%) peak plasma concentration were ≤2 h in all but one case (median: 1 h). PGE₂ production in tissue was significantly blocked by the COX-2 inhibitor starting with the appearance of etoricoxib in tissue and lasting for the whole observation period of 24 h (P < 0.01). In conclusion, etoricoxib reaches the CSF and site of surgery at effective concentrations and reduces PGE₂ production at the presumed site of action.

Etoricoxib: a review of its use in the symptomatic treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis and acute gouty arthritis

Etoricoxib is a selective cyclo-oxygenase (COX)-2 inhibitor, approved in Europe for the symptomatic treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis and acute gouty arthritis. Etoricoxib provided similar symptomatic relief to nonselective NSAIDs in patients with these conditions, and to celecoxib in patients with osteoarthritis. The drug was associated with fewer uncomplicated upper gastrointestinal (GI) adverse events than nonselective NSAIDs, and was noninferior to diclofenac in terms of the rate of thrombotic cardiovascular (CV) events. Etoricoxib may be considered as a treatment option for patients requiring NSAID therapy, particularly those at risk of upper GI events, after careful consideration of significant risk factors for CV events (including uncontrolled hypertension). As with all NSAIDs, the potential GI and CV risks of treatment with etoricoxib should be weighed against the potential benefits in individual patients, and it should be administered at the lowest effective dose for as short a duration as possible.

Prostaglandin E2 inhibits eosinophil trafficking through E-prostanoid 2 receptors

The accumulation of eosinophils in lung tissue is a hallmark of asthma, and it is believed that eosinophils play a crucial pathogenic role in allergic inflammation. Prostaglandin (PG) E(2) exerts anti-inflammatory and bronchoprotective mechanisms in asthma, but the underlying mechanisms have remained unclear. In this study we show that PGE(2) potently inhibits the chemotaxis of purified human eosinophils toward eotaxin, PGD(2), and C5a. Activated monocytes similarly attenuated eosinophil migration, and this was reversed after pretreatment of the monocytes with a cyclooxygenase inhibitor. The selective E-prostanoid (EP) 2 receptor agonist butaprost mimicked the inhibitory effect of PGE(2) on eosinophil migration, whereas an EP2 antagonist completely prevented this effect. Butaprost, and also PGE(2), inhibited the C5a-induced degranulation of eosinophils. Moreover, selective kinase inhibitors revealed that the inhibitory effect of PGE(2) on eosinophil migration depended upon activation of PI3K and protein kinase C, but not cAMP. In animal models, the EP2 agonist butaprost inhibited the rapid mobilization of eosinophils from bone marrow of the in situ perfused guinea pig hind limb and prevented the allergen-induced bronchial accumulation of eosinophils in OVA-sensitized mice. Immunostaining showed that human eosinophils express EP2 receptors and that EP2 receptor expression in the murine lungs is prominent in airway epithelium and, after allergen challenge, in peribronchial infiltrating leukocytes. In summary, these data show that EP2 receptor agonists potently inhibit eosinophil trafficking and activation and might hence be a useful therapeutic option in eosinophilic diseases.