Subcutaneous injection of diclofenac for the treatment of pain following minor orthopedic surgery (DIRECT study): a randomized trial

OBJECTIVES

Parenteral diclofenac is frequently used for analgesia following minor orthopedic interventions. Currently available diclofenac formulations are for intramuscular (IM) or intravenous injection. A new 1 mL volume formulation of diclofenac containing hydroxypropyl-β-cyclodextrin (HPβCD) allows both SC and IM administration. The objective of this open-label, randomized, parallel group, active-controlled study was to assess the safety and efficacy of 75 mg diclofenac HPβCD, administered SC or IM, compared with IM Voltaren® 75 mg in inpatients undergoing minor orthopedic surgeries with moderate-to-severe postoperative pain.

METHODS

A total of 325 patients were randomized to treatment. Surgery-related pain was comparable between groups before treatment and rapidly declined in all patients following diclofenac injection. The primary endpoint was investigator-assessed local tolerability up to 18 hours postinjection (redness, swelling, and hardening at the injection site each scored on a 4-point scale where 0 = none, 1 = mild, 2 = moderate, and 3 = severe).

RESULTS

Local tolerability was found to be optimal for all the injected formulations, with mean overall scores (0 to 9) of 0.57, 0.31, and 0.26, for diclofenac HPβCD SC, diclofenac HPβCD IM, and Voltaren® IM, respectively. Consistently, the overall tolerability as judged by the patients and investigators was reported as good or excellent in more than 90% of cases in all groups.

CONCLUSIONS

Overall, the study results indicate that safety and efficacy were similar irrespective of the diclofenac formulation used; thus, the new SC diclofenac HPβCD has an acceptable tolerability profile and may be considered a valid alternative to IM-delivered diclofenac formulations.

Pharmaceuticals and personal care products in the aquatic environment in China: a review

Pharmaceuticals and personal care products (PPCPs) have been detected as contaminants of emerging concern ubiquitously in the aquatic environment in China and worldwide. A clear picture of PPCP contamination in the Chinese aquatic environment is needed to gain insight for both research and regulatory needs (e.g. monitoring, control and management). The occurrence data of 112 PPCPs in waters and sediments in China has been reviewed. In most cases, the detected concentration of these PPCPs in waters and sediments were at ng/L and ng/g levels, which were lower than or comparable to those reported worldwide. A screening level risk assessment (SLERA) identified six priority PPCPs in surface waters, namely erythromycin, roxithromycin, diclofenac, ibuprofen, salicylic acid and sulfamethoxazole. The results of SLERA also revealed that the hot spots for PPCP pollution were those river waters affected by the megacities with high density of population, such as Beijing, Tianjin, Guangzhou and Shanghai. Limitations of current researches and implications for future research in China were discussed. Some regulatory issues were also addressed.

Randomized controlled study of the antipyretic efficacy of oral paracetamol, intravenous paracetamol, and intramuscular diclofenac in patients presenting with fever to the emergency department

Background

Fever is a common problem in adults visiting the emergency department. Extensive studies have been done in children comparing the efficacy of various antipyretics. However, studies on the efficacy of antipyretic drugs in adults are very scarce. To the best of our knowledge, no controlled trial has been carried out comparing the antipyretic efficacy of paracetamol (oral and intravenous) and intramuscular diclofenac in adults.

Methods

In this parallel-group, open-label trial, participants aged 14–75 years presenting with fever who had a temperature of more than 38.5°C were enrolled and treated. Participants were randomly allocated to receive treatment with 1,000 mg oral paracetamol (n = 145), 1,000 mg intravenous paracetamol (n = 139), or 75 mg intramuscular diclofenac (n = 150). The primary outcome was degree of reduction in mean oral temperature at 90 minutes. The efficacy of diclofenac versus oral and intravenous paracetamol was assessed by superiority comparison. Analysis was done using intention to treat principles.

Results

After 90 minutes, all three groups showed a significant reduction in mean temperature, with intramuscular diclofenac showing the greatest reduction (−1.44 ± 0.43, 95% confidence interval [CI] −1.4 to −2.5) and oral paracetamol the least (−1.08 ± 0.51, 95% CI −0.99 to −2.2). After 120 minutes, there was a significant difference observed in the mean change from baseline temperature between the three treatment groups (P < 0.0001). Significant changes in temperature were observed in favor of intramuscular diclofenac over oral and intravenous paracetamol at each time point from 60 minutes through 120 minutes inclusive.

Conclusion

Both intramuscular diclofenac and intravenous paracetamol showed superior antipyretic activity than oral paracetamol. However, in view of its ease of administration, intramuscular diclofenac can be used as a first-choice antipyretic in febrile adults in the emergency department.

Synthesis and pharmacological evaluation of antiinflammatory mutual amide prodrugs

Nonsteroidal antiinflammatory drugs have been widely used for the management of inflammation, pain and nociception. Gastric intolerance caused by most of the nonsteroidal antiinflammatory drugs used today restricts their use. Several approaches have been proposed to modify the parent nonsteroidal antiinflammatory drugs molecule in order to reduce their gastric toxicity. Oral prodrug approach is one of such approaches. In the present work three nonsteroidal antiinflammatory drugs viz. ibuprofen, diclofenac, and flurbiprofen were conjugated with sulfonamides like sulphamethoxazole and sulphanilamide via amide bond using dicyclohexylcarbodiimide coupling reaction. The synthesized prodrugs were screened for their analgesic and antiinflammatory activity using Eddy's hot plate, acetic acid-induced writhing and carrageenan-induced rat paw edema method, respectively. These prodrugs were also evaluated for their ulcerogenic potential. All synthesized prodrugs were found to be less ulcerogenic than their parent nonsteroidal antiinflammatory drugs and showed better activity profile in terms of analgesic and antiinflammatory activity as compared to their respective parent drugs.

[Clinical improvement of diabetic neuropathy with carbamazepine or diclofenac treatment]

BACKGROUND

diabetic neuropathy (DN) affects diverse aspects of a patient's life and there is not an optimal treatment. We did a comparative study of clinical improvement of DN with carbamazepine versus diclofenac.

METHODS

a prospective and longitudinal study of two groups with signs and symptoms of DN was done. One group had 30 patients who used carbamazepine with an initial dose of 200 mg, every 24 hours for one week, with a gradual increase of up to 200 mg every 6 hours for 10 months. The other group had 29 patients who used diclofenac sodium 100 mg every 12 hours. Bimonthly evaluations were made to graduate the pain according to the patients' perception and laboratory studies that included glucose and lipids profile. The statistical test used was ANOVA.

RESULTS

the patients who used carbamazepine presented absence of pain after 10 months compared with the diclofenac group (p < 0.01). The presence of cramps, muscular strength, pulses, perception of temperature and pressure improved significantly (p < 0.05) with the use of carbamazepine. On the other hand, muscular strength, tact and perception of temperature were deteriorated with the use of diclofenac.

CONCLUSIONS

it is important to provide the appropriate treatment to diabetic patients with DN.

Proteomic profiling in incubation medium of mouse, rat and human precision-cut liver slices for biomarker detection regarding acute drug-induced liver injury

Drug-induced liver injury is one of the leading causes of drug withdrawal from the market. In this study, we investigated the applicability of protein profiling of the incubation medium of human, mouse and rat precision-cut liver slices (PCLS) exposed to liver injury-inducing drugs for biomarker identification, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. PCLS were incubated with acetaminophen (APAP), 3-acetamidophenol, diclofenac and lipopolysaccharide for 24-48 h. PCLS medium from all species treated with APAP demonstrated similar changes in protein profiles, as previously found in mouse urine after APAP-induced liver injury, including the same key proteins: superoxide dismutase 1, carbonic anhydrase 3 and calmodulin. Further analysis showed that the concentration of hepcidin, a hepatic iron-regulating hormone peptide, was reduced in PCLS medium after APAP treatment, resembling the decreased mouse plasma concentrations of hepcidin observed after APAP treatment. Interestingly, comparable results were obtained after 3-acetamidophenol incubation in rat and human, but not mouse PCLS. Incubation with diclofenac, but not with lipopolysaccharide, resulted in the same toxicity parameters as observed for APAP, albeit to a lesser extent. In conclusion, proteomics can be applied to identify potential translational biomarkers using the PCLS system.

Role of drug-independent stress factors in liver injury associated with diclofenac intake

Although a basic understanding of the chemical and biological events leading to idiosyncratic drug toxicity is still lacking, it appears that drug-independent risk factors that increase reactive metabolite formation or alter cellular stress and immune response may be critical determinants in the response to an otherwise non-toxic drug. Thus, we were interested to determine the impact of various drug-independent stress factors - lipopolysaccharide (LPS), poly I:C (PIC) or glutathione depletion via buthionine sulfoximine (BSO) - on the toxicity of diclofenac (Dcl), a model drug associated with rare but significant cases of serious hepatotoxicity, and to understand if enhanced toxicity occurs through alterations of drug metabolism and/or modulation of stress response pathways. Co-treatment of rats repeatedly given therapeutic doses of Dcl for 7 days with a single dose of LPS 2h before the last Dcl dose resulted in severe liver toxicity. Neither LPS nor diclofenac alone or in combination with PIC or BSO had such an effect. While it is thought that bioactivation to reactive Dcl acyl glucuronides (AG) and subsequent protein adduct formation contribute to Dcl induced liver injury, LC-MS/MS analyses did not reveal increased formation of 4'- and 5-hydroxy-Dcl, Dcl-AG or Dcl-AG dependent protein adducts in animals treated with LPS/Dcl. Hepatic gene expression analysis suggested enhanced activation of NFκB and MAPK pathways and up-regulation of co-stimulatory molecules (IL-1β, TNF-α, CINC-1) by LPS/Dcl and PIC/Dcl, while protective factors (HSPs, SOD2) were down-regulated. LPS/Dcl led to extensive release of pro-inflammatory cytokines (IL-1β, IL-6, IFN-γ, TNF-α) and factors thought to constitute danger signals (HMGB1, CINC-1) into plasma. Taken together, our results show that Dcl enhanced the inflammatory response induced by LPS - and to a lesser extent by PIC - through up-regulation of pro-inflammatory molecules and down-regulation of protective factors. This suggests sensitization of cells to cellular stress mediated by non-drug-related risk factors by therapeutic doses of Dcl, rather than potentiation of Dcl toxicity by the stress factors.

The Antiinflammatory and Antiarthritic Properties of Ethanol Extract of Hedera helix

The ethanol Hedera helix plant extract was tested for its antiinflammatory properties. Intraperitoneal injections of 7.5 ml/kg wt ethanol extract showed antiinflammatory activity with 88.89% inhibition as compared to reference drug diclofenac, which showed 94.44% inhibition in formalin-induced paw oedema. As formalin-induced paw oedema closely resembles human arthritis, the antiarthritic property of ethanol extract of Hedera helix was also investigated. The visible reduction in arthritic symptoms by extract of Hedera helix suggests the potential of the plant extract against inflammation and arthritis.

The effects of indomethacin, diclofenac, and acetaminophen suppository on pain and opioids consumption after cesarean section

BACKGROUND

Cesarean section is one of the common surgeries of women. Acute post-operative pain is one of the recognized post-operative complications.

AIMS

This study was planned to compare the effects of suppositories, indomethacin, diclofenac and acetaminophen, on post-operative pain and opioid usage after cesarean section.

MATERIALS AND METHODS

In this double-blind clinical trial study, 120 candidates of cesarean with spinal anesthesia and American Society of Anesthesiologists (ASA) I-II were randomly divided into four groups. Acetaminophen, indomethacin, diclofenac, and placebo suppositories were used in groups, respectively, after operation and the dosage was repeated every 6 h and pain score and opioid usage were compared 24 h after the surgery. The severity of pain was recorded on the basis of Visual Analog Scale (VAS) and if severe pain (VAS > 5) was observed, 0.5 mg/kg intramuscular pethidine had been used.

STATISTICAL ANALYSIS USED

The data were analyzed in SPSS software version 15 and analytical statistics such as ANOVA, Chi-square, and Tukey's honestly significant difference (HSD) post-hoc.

RESULTS

Pain score was significantly higher in control group than other groups, and also pain score in acetaminophen group was higher than indomethacin and diclofenac. The three intervention groups received the first dose of pethidine far more than control group and the distance for diclofenac and indomethacin were significantly longer (P < 0.001). The use of indomethacin, diclofenac, and acetaminophen significantly reduces the amount of pethidine usage in 24 h after the surgery relation to control group.

CONCLUSIONS

Considering the significant decreasing pain score and opioid usage especially in indomethacin and diclofenac groups rather than control group, it is suggested using of indomethacin and diclofenac suppositories for post-cesarean section analgesia.

Single-dose and multiple-dose pharmacokinetics and dose proportionality of intravenous and intramuscular HPβCD-diclofenac (Dyloject) compared with other diclofenac formulations

STUDY OBJECTIVE

To evaluate single- and repeated-dose pharmacokinetics (PK) and dose proportionality of hydroxypropyl-β-cyclodextrin (HPβCD)-diclofenac compared with Voltarol after intravenous (IV) and intramuscular (IM) administration.

DESIGN

Study 1: Single-dose randomized four-way crossover study. Study 2: Multiple-dose randomized three-way crossover study.

SETTING

Clinical research center.

SUBJECTS

Healthy adult volunteers.

INTERVENTION

Study 1: Subjects received HPβCD-diclofenac and Voltarol, IV and IM, with a 5-day washout between treatment periods. Study 2: Subjects received two doses of IV HPβCD-diclofenac and oral Cataflam once every 6 hours for four doses with a 48-hour washout period between treatment periods.

MEASUREMENTS AND MAIN RESULTS

Study 1: IV HPβCD-diclofenac had a higher peak plasma concentration (Cmax ) and earlier time to reach maximum plasma concentration (Tmax ), but equivalent plasma exposure (area under the curve from time zero to t [AUC0-t ]) to IV Voltarol. The geometric mean ratio of HPβCD-diclofenac (IV) to Voltarol (IV) for AUC0-t was 106.27%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IM) for AUC0-t was 110.91%. The geometric mean ratio of HPβCD-diclofenac (IV) to HPβCD-diclofenac (IM) for AUC0-t was 101.25%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IV) for AUC0-t was 104.96%. Study 2: Cmax for diclofenac was 2904 and 6031 ng/ml after the first IV dose of 18.75 and 37.5 mg HPβCD-diclofenac, respectively, and was 3090 and 5617 ng/ml after the fourth dose, indicating no accumulation. Plasma exposures to 18.75 mg (866 ng·hour/ml) and 37.5 mg (1843 ng·hour/ml) IV HPβCD-diclofenac bracketed that of oral Cataflam 50 mg (1473 ng·hour/ml).

CONCLUSIONS

Study 1: Bioavailability in terms of AUC after IV administration was equivalent for HPβCD-diclofenac compared with Voltarol and after IM administration of HPβCD-diclofenac and Voltarol. Bioavailability in terms of AUC after IM administration of HPβCD-diclofenac was equivalent to IV administration of HPβCD-diclofenac and IV administration of Voltarol. Study 2: HPβCD-diclofenac showed dose proportionality after single- and multiple-dose administration and no accumulation of HPβCD-diclofenac. HPβCD-diclofenac was safe and well tolerated following IV and IM administration.

Preparation and evaluation of a multimodal minoxidil microemulsion versus minoxidil alone in the treatment of androgenic alopecia of mixed etiology: a pilot study

Background:

The variable success of topical minoxidil in the treatment of androgenic alopecia has led to the hypothesis that other pathways could mediate this form of hair loss, including infection and/or microinflammation of the hair follicles. In this study, we prepared a multimodal microemulsion comprising minoxidil (a dihydrotestosterone antagonist), diclofenac (a nonsteroidal anti-inflammatory agent), and tea tree oil (an anti-infective agent). We investigated the stability and physicochemical properties of this formulation, and its therapeutic efficacy compared with a formulation containing minoxidil alone in the treatment of androgenic alopecia.

Methods:

We developed a multimodal oil/water (o/w) microemulsion, a formulation containing minoxidil alone, and another containing vehicle. A three-phase diagram was constructed to obtain the optimal concentrations of the selected oil, surfactant, and cosurfactant. Thirty-two men aged 18–30 years were randomized to apply 1 mL of microemulsion containing the multimodal formulation (formulation A, n = 11), minoxidil alone (formulation B, n = 11) or placebo (formulation C, n = 10) twice daily to the affected area for 32 weeks. Efficacy was evaluated by mean hair count, thickness, and weight on the targeted area of the scalp. Global photographs were taken, changes in the area of scalp coverage were assessed by patients and external investigators, and the benefits and safety of the study medications were evaluated. The physical stability of formula A was examined after a shelf storage period of 24 months.

Results:

Formulation A achieved a significantly superior response than formulations B and C in terms of mean hair count (P < 0.001), mean hair weight (P < 0.001), and mean hair thickness (P < 0.05). A patient self-assessment questionnaire demonstrated that the multimodal minoxidil formulation significantly (P < 0.001) slowed hair loss, increased hair growth, and improved appearance, and showed no appreciable side effects, such as itching and/or inflammation of the scalp compared with the minoxidil alone and placebo formulations. These improvements were in agreement with the photographic assessments made by the investigators. Formula A was shown to be an o/w formulation with consistent pH, viscosity, specific gravity, and homogeneity, and was physically stable after 24 months of normal storage.

Conclusion:

A multimodal microemulsion comprising minoxidil, diclofenac, and tea tree oil was significantly superior to minoxidil alone and placebo in terms of stability, safety, and efficacy, and achieved an earlier response in the treatment of androgenic alopecia compared with minoxidil alone in this 32-week pilot study.

Disposition kinetics of diclofenac in the dual perfused rat liver

This study investigates the hepatic disposition of diclofenac as a function of route of input: portal vein (PV) versus hepatic artery (HA) in the presence of its binding protein, albumin. The in situ dual perfused rat liver was performed using Krebs bicarbonate buffer containing human serum albumin (HSA, 0.25%-1%) at constant PV (12 mL/min) and HA (3 mL/min) flow rates. Bolus doses of [(14) C]-diclofenac and (125) I-labeled HSA were injected randomly into the HA or PV and then, after an appropriate interval, into the alternate vessel. Regardless of route of input and perfusion medium protein concentration, the hepatic outflow profile of diclofenac displayed a characteristic sharp peak followed by a slower eluting tail, indicating that its radial distribution is not instantaneous. Based on the estimated effective permeability-surface area product/blood flow ratio, hepatic uptake of diclofenac is governed by both perfusion and permeability. Fractional effluent recovery (F) increased as unbound diclofenac fraction in the perfusate decreased. Although no significant difference in hepatic clearance of diclofenac as a function of route of delivery at 0.5% and 1% HSA, it was demonstrable at 0.25% HSA (p < 0.001), when the extraction ratio is higher.

Nonsteroidal anti-inflammatory drug-induced visible and invisible small intestinal injury

Permeation of the small intestinal mucosa is a key mechanism in the induction of enteropathy. We investigated the effect of rebamipide in healthy subjects with diclofenac-induced small intestinal damage and permeability. In this crossover study, each treatment period was 1 week with a 4-week washout period. Diclofenac (75 mg/day) and omeprazole (20 mg/day) plus rebamipide (300 mg/day) or placebo were administered. Capsule endoscopy and a sugar permeability test were performed on days 1 and 7 in each period. Ten healthy subjects were enrolled. Small intestinal injuries were observed on day 7 in 6 of 10 subjects in both groups. Urinary excretion of administered lactulose increased from 0.30% to 0.50% of the initial dose during the first treatment period in the placebo group, and from 0.13% to 0.33% in the rebamipide group. Despite recovery from small-intestinal mucosal damage, the increased permeability in both groups resulted in sustained high levels of lactulose (0.50% to 1.06% in the placebo group and 0.33% to 1.12% in the rebamipide group) through the 4-week washout period. Diclofenac administration induced enteropathy and hyperpermeability of the small intestine. The sustained hyperpermeability during the washout period may indicate the presence of invisible fragility.

Osteoarthritis guidelines: a progressive role for topical nonsteroidal anti-inflammatory drugs

Current treatment guidelines for the treatment of chronic pain associated with osteoarthritis reflect the collective clinical knowledge of international experts in weighing the benefits of pharmacologic therapy options while striving to minimize the negative effects associated with them. Consideration of disease progression, pattern of flares, level of functional impairment or disability, response to treatment, coexisting conditions such as cardiovascular disease or gastrointestinal disorders, and concomitant prescription medication use should be considered when creating a therapeutic plan for a patient with osteoarthritis. Although topical nonsteroidal anti-inflammatory drugs historically have not been prevalent in many of the guidelines for osteoarthritis treatment, recent evidence-based medicine and new guidelines now support their use as a viable option for the clinician seeking alternatives to typical oral formulations. This article provides a qualitative review of these treatment guidelines and the emerging role of topical nonsteroidal anti-inflammatory drugs as a therapy option for patients with localized symptoms of osteoarthritis who may be at risk for oral nonsteroidal anti-inflammatory drug-related serious adverse events.

Effect of the NSAID diclofenac on 99mTc-MAG3 and 99mTc-DTPA renography

Renal function and disease are commonly evaluated by radionuclide studies. The choice of radiopharmaceutical agent for various studies is crucial for proper interpretation. (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) is excreted almost exclusively by the renal tubules, whereas (99m)Tc-diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) is predominantly excreted by glomerular filtration. The present study compared the effect of the nonsteroidal antiinflammatory drug (NSAID) diclofenac, which is the most commonly used drug to relieve kidney pain, on the kinetic behavior of administered (99m)Tc-MAG3 and (99m)Tc-DTPA in experimental animals.

METHODS

Two groups of 12 New Zealand White rabbits ((99m)Tc-MAG3 and (99m)Tc-DTPA) were used for the renography. Each rabbit served as its own control. The animals were given 60 mL of saline intravenously 30 min before each renographic study. A baseline study (control) was done by injecting 48 MBq (1.3 mCi) of (99m)Tc-MAG3, and renography was performed. Two days later, a single intravenous dose of diclofenac (2 mg/kg) (treated animals) was given, and after 20 min, (99m)Tc-MAG3 renography was performed. This procedure was repeated for the (99m)Tc-DTPA group after administration of 96 MBq (2.6 mCi) of the tracer. Dynamic images (as 2-s frames for the first minute and 30-s frames for the next 30 min on a 64 × 64 matrix) were acquired using a γ-camera equipped with a low-energy high-resolution collimator interfaced with a computer. Regions of interest were drawn over the whole kidneys. Time-activity curves were generated from the region of interest. Time to peak activity (T(max)), time from peak to 50% activity (T(1/2)), and the uptake slope of each kidney were calculated from the renograms for control and treated rabbits.

RESULTS

Administration of diclofenac shifted the experimental renogram curves to the right, compared with the control curves, indicating that there was a delayed renal uptake of the 2 tracers and clearance of the radioactivity. The calculated average values of T(max) for control and treated rabbits using (99m)Tc-MAG3 were 1.8 ± 0.5 and 6.35 ± 0.4 min, respectively, whereas those of (99m)Tc-DTPA were 3.4 ± 0.4 and 18.2 ± 2 min, respectively. The T1/2 for control and treated rabbits for (99m)Tc-MAG3 were 3.2 ± 0.07 and 6.6 ± 0.07 min, respectively, whereas those for (99m)Tc-DTPA were 10.1 ± 1 and 35 ± 4 min, respectively. The differences were statistically significant (P < 0.05).

CONCLUSION

This study showed that diclofenac delayed both T(max) and T1/2. The NSAID-induced kinetic changes were considerably greater for (99m)Tc-DTPA than for (99m)Tc-MAG3. On the basis of these findings, it is suggested that (99m)Tc-MAG3 be used to perform renography for studies involving the use of NSAID administration to decrease any change that may occur due to the type of tracer and not to the condition of the kidney.

Effects of NSAIDs and paracetamol (acetaminophen) on protein kinase C epsilon translocation and on substance P synthesis and release in cultured sensory neurons

Celecoxib, diclofenac, ibuprofen, and nimesulide are nonsteroidal anti-inflammatory drugs (NSAIDs) very commonly used for the treatment of moderate to mild pain, together with paracetamol (acetaminophen), a very widely used analgesic with a lesser anti-inflammatory effect. In the study reported here, we tested the efficacy of celecoxib, diclofenac, and ibuprofen on preprotachykinin mRNA synthesis, substance P (SP) release, prostaglandin E₂ (PGE₂) release, and protein kinase C epsilon (PKCɛ) translocation in rat cultured sensory neurons from dorsal root ganglia (DRGs). The efficacy of these NSAIDs was compared with the efficacy of paracetamol and nimesulide in in vitro models of hyperalgesia (investigated previously). While nimesulide and paracetamol, as in previous experiments, decreased the percentage of cultured DRG neurons showing translocation of PKCɛ caused by 100 nM thrombin or 1 μM bradykinin in a dose-dependent manner, the other NSAIDs tested did not have a significant effect. The amount of SP released by peptidergic neurons and the expression level of preprotachykinin mRNA were assessed in basal conditions and after 70 minutes or 36 hours of stimulation with an inflammatory soup (IS) containing potassium chloride, thrombin, bradykinin, and endothelin-1. The release of SP at 70 minutes was inhibited only by nimesulide, while celecoxib and diclofenac were effective at 36 hours. The mRNA basal level of the SP precursor preprotachykinin expressed in DRG neurons was reduced only by nimesulide, while the increased levels expressed during treatment with the IS were significantly reduced by all drugs tested, with the exception of ibuprofen. All drugs were able to decrease basal and IS-stimulated PGE₂ release. Our study demonstrates novel mechanisms of action of commonly used NSAIDS.

Diclofenac: New data on chronic toxicity and bioconcentration in fish

Diclofenac (DCF) is a widely used nonsteroidal anti-inflammatory drug that is regularly detected in surface waters. To support a robust aquatic risk assessment, two early life stage (ELS) tests, compliant with the Organisation for Economic Co-operation and Development (OECD) test guideline 210, were conducted in rainbow trout and in zebrafish. Population relevant endpoints, such as hatching, growth, and survival, and in the trout study, histopathological effects in potential target organs, were examined. The bioconcentration of DCF in rainbow trout was measured in a separate study according to OECD test guideline 305. The bioconcentration factor (BCF) in rainbow trout remained below 10, demonstrating no relevant bioconcentration of DCF in fish. In the rainbow trout ELS test, the no observed effect concentration (NOEC) including histopathology was 320 µg/L. The effect of DCF on zebrafish growth was less clear, and the NOEC can be interpreted as 10 µg/L. However, for a number of reasons, the authors consider the moderately reduced growth of zebrafish exposed to concentrations of up to 320 µg/L not a repeatable, treatment-related effect of DCF. This leads us to a conclusion that DCF has, with high probability, no adverse effect on both fish species up to 320 µg/L. This NOEC indicates a sufficient safety margin for fish populations, because concentrations of DCF in European rivers are in the range of ng/L to low µg/L.

Non-steroidal anti-inflammatory drugs do not influence the urinary testosterone/epitestosterone glucuronide ratio

The UDP Glucuronosyl Transferase (UGT) enzymes are important in the pharmacokinetics, and conjugation, of a variety of drugs including non-steroidal anti-inflammatory drugs (NSAIDs) as well as anabolic androgenic steroids (AAS). Testosterone glucuronidation capacity is strongly associated with a deletion polymorphism in the UGT2B17 gene. As the use of high doses of NSAIDs has been observed in athletes there is a risk for a drug-drug interaction that may influence the doping tests for AAS. In vitro studies show inhibitory potential on UGT2B7, 2B15, and 2B17 enzymes by NSAIDs. The aim of this study was to investigate if concomitant use of NSAIDs and a single dose of testosterone enanthate would affect the excretion rate of testosterone and epitestosterone glucuronide (TG and EG) as well as the T/E ratio, thereby affecting the outcome of the testosterone doping test. The study was designed as an open, randomized, cross-over study with subjects being their own control. The 23 male healthy volunteers, with either two, one or no allele (ins/ins, ins/del, or del/del) of the UGT2B17 gene, received the maximum recommended dose of NSAID (Ibuprofen or Diclofenac) for 6 days. On day three, 500 mg of testosterone enanthate was administered. Spot urine samples were collected for 17 days. After a wash-out period of 4 months the volunteers received 500 mg testosterone enanthate only, with subsequent spot urine collection for 14 days. The glucuronides of testosterone and epitestosterone were quantified. NSAIDs did not affect the excretion of TG or EG before the administration of testosterone. The concomitant use of NSAIDs and testosterone slightly increased the TG excretion while the EG excretion was less suppressed compared to testosterone use only. The effects of the NSAIDs on the TG and EG excretion did not differ between the UGT2B17 genotype groups. In conclusion, the outcome of testosterone doping tests does not seem to be affected by the use of NSAIDs.

Long-term tolerability of topical diclofenac sodium 1% gel for osteoarthritis in seniors and patients with comorbidities

Background

Adverse events associated with nonsteroidal anti-inflammatory drugs (NSAIDs) used to treat knee and hand osteoarthritis may be more frequent in certain patient populations. Topical NSAIDs, such as diclofenac sodium 1% gel (DSG), have equivalent efficacy and fewer adverse events compared with oral NSAIDs. This post hoc analysis assessed the long-term tolerability of DSG in elderly patients and patients with an elevated risk of gastrointestinal, cardiovascular, and renal adverse events.

Methods

Patients ≥ 35 years of age with knee osteoarthritis applied DSG (4 g) to one or both knees for 12 weeks during either of two primary studies and for 9 months during a long-term extension study. Other patients entered the long-term extension study directly and applied DSG for 12 months. Safety was assessed by reported adverse events. Subpopulations were defined based on age, or the comorbidities of hypertension, type 2 diabetes mellitus, and cerebrovascular or cardiovascular disease.

Results

The safety population consisted of 947 patients who received at least one dose of DSG during the primary or extension study. Patients aged < 65 years (68.2%) and ≥65 years (67.2%) experienced any adverse event at similar rates. The percentage of patients who experienced any adverse event was similar between patients with and without hypertension (65.5% versus 69.7%, respectively), type 2 diabetes mellitus (64.0% versus 68.2%), or cerebrovascular or cardiovascular disease (61.9% versus 68.5%). Among the 15 patients with all three comorbidities, the percentage of patients with any adverse event (53.3%) was less than that of patients who did not have all three comorbidities (68.0%).

Conclusion

These results suggest that long-term DSG treatment is safe in patient subpopulations with an elevated risk of NSAID-related adverse events, such as the elderly and those with the comorbidities of hypertension, type 2 diabetes mellitus, and cerebrovascular or cardiovascular disease.

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.

Inhibition of glycogen synthase kinase-3β prevents NSAID-induced acute kidney injury

Clinical use of nonsteroidal anti-inflammatory drugs (NSAIDs) like diclofenac (DCLF) is limited by multiple adverse effects, including renal toxicity leading to acute kidney injury. In mice with DCLF-induced nephrotoxicity, TDZD-8, a selective glycogen synthase kinase (GSK)3β inhibitor, improved acute kidney dysfunction and ameliorated tubular necrosis and apoptosis associated with induced cortical expression of cyclooxygenase-2 (COX-2) and prostaglandin E2. This renoprotective effect was blunted but still largely preserved in COX-2-null mice, suggesting that other GSK3β targets beyond COX-2 functioned in renal protection. Indeed, TDZD-8 diminished the mitochondrial permeability transition in DCLF-injured kidneys. In vitro, GSK3β inhibition reinstated viability and suppressed necrosis and apoptosis in DCLF-stimulated tubular epithelial cells. DCLF elicited oxidative stress, enhanced the activity of the redox-sensitive GSK3β, and promoted a mitochondrial permeability transition by interacting with cyclophilin D, a key component of the mitochondrial permeability transition pore. TDZD-8 blocked GSK3β activity and prevented GSK3β-mediated cyclophilin D phosphorylation and the ensuing mitochondrial permeability transition, concomitant with normalization of intracellular ATP. Conversely, ectopic expression of a constitutively active GSK3β abolished the effects of TDZD-8. Hence, inhibition of GSK3β ameliorates NSAID-induced acute kidney injury by induction of renal cortical COX-2 and direct inhibition of the mitochondrial permeability transition.

Design, synthesis and preliminary pharmacological evaluation of new non-steroidal anti-inflammatory agents having a 4-(methylsulfonyl) aniline pharmacophore

A series of 4-(methylsulfonyl)aniline derivatives were synthesized in order to obtain new compounds as a potential anti-inflammatory agents with expected selectivity against COX-2 enzyme. In vivo acute anti-inflammatory activity of the final compounds 11-14 was evaluated in rat using an egg-white induced edema model of inflammation in a dose equivalent to 3 mg/Kg of diclofenac sodium. All tested compounds produced significant reduction of paw edema with respect to the effect of propylene glycol 50% v/v (control group). Moreover, the activity of compounds 11 and 14 was significantly higher than that of diclofenac sodium (at 3 mg/Kg) in the 120-300 minute time interval, while compound 12 expressed a comparable effect to that of diclofenac sodium in the 60-240 minute time interval time, and compound 13 showed a comparable effect to that of diclofenac sodium at all experimental times. The result of this study indicates that the incorporation of the 4-(methylsulfonyl)aniline pharamacophore into naproxen, indomethacine, diclofenac and mefanamic acid maintained their anti-inflammatory activity and may increase selectivity towards the COX-2 enzyme which will be confirmed in the future by assessing COX-2: COX-1 inhibitory ratios using a whole blood assay.

In the Huh7 Hepatoma Cells Diclofenac and Indomethacin Activate Differently the Unfolded Protein Response and Induce ER Stress Apoptosis

Non-steroidal anti-inflammatory drugs (NSAIDs) are cyclooxygenases (COXs) inhibitors frequently used in the treatment of acute and chronic inflammation. Side effects of NSAIDs are often due to their ability to induce apoptosis. Located at the Endoplasmic Reticulum membranes a tripartite signalling pathway, collectively known as the Unfolded Protein Response (UPR), decides survival or death of cells exposed to cytotoxic agents. To shed light on the molecular events responsible for the cytotoxicity of NSAIDs, we analysed the ability of diclofenac and indomethacin to activate the UPR in the human hepatoma cell line Huh7. We report that both NSAIDs can induce differently the single arms of the UPR. We show that indomethacin turns on the PERK and, only in part, the ATF6 and IRE1 pathways. Instead, diclofenac reduces the expression of ATF6 and does not stimulate the IRE1 endonuclease, which drives the expression of the prosurvival factor XBP1. Diclofenac, as well as indomethacin, is able to activate efficiently only the PERK pathway of the UPR, which induces the expression of the proapoptotic GADD153/CHOP protein. Our results highlight the importance of the UPR in evaluating the potential of drugs to induce apoptosis.

Comparison of the anti-inflammatory and analgesic effects in rats of diclofenac-sodium, felbinac and indomethacin patches

BACKGROUND

Topically applied nonsteroidal anti-inflammatory drugs (NSAIDs) are used widely for the treatment of pain and inflammation in musculoskeletal disorders. This study compared the analgesic and anti-inflammatory effects of patches of 1% diclofenac-sodium, 3.5% and 0.5% felbinac and 3.75% indomethacin in rats using the carrageenan-induced paw pad edema model and the brewer's yeast-induced hyper algesia model. Two studies were conducted: in the preliminary study, the patch was removed at 2 or 24 hrs after application, and in the main study the patch was removed at 2 hrs. The volume of the right hind paw and the pain threshold were assessed at 1, 3, 5, and 7 hrs after induction of inflammation in both studies.

RESULTS

In the main study, the edema ratio in the 1% diclofenac group at 5 hrs after induction of inflammation and the AUEC (Area Under the Effect Curve) were significantly lower than in the control animals (p=0.009). The edema suppression rate in the 1% diclofenac group (12.1-33.2%) was higher than in the 3.5% and 0.5% felbinac and 3.75% indomethacin groups. The pain threshold ratio did not decrease in the 1% diclofenac group and it was significantly higher than in the control group at 3 (p=0.0004) and 5 hrs (p=0.029). The 1/AUEC was significantly lower than that in the control group (p=0.004) and the lowest among all the NSAID groups.

CONCLUSIONS

This study demonstrated that the analgesic and anti-inflammatory effects of the 1% diclofenac sodium patch in a rat model may be exerted more promptly and persistently than with the 3.5% and 0.5% felbinac and 3.75% indomethacin patches.

Antioxidant, Antinociceptive and Anti-inflammatory Activities of Ethanolic Extract of Leaves of Alocasia indica (Schott.)

Extracts obtained from the leaves of various Alocasia species have been used in India as folk remedy for the treatment of various inflammatory ailments including rheumatism and bruise. The ethanolic extract of leaves of Alocasia indica Schott. was evaluated by using different in vitro antioxidant models of screening like scavenging of 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical, nitric oxide radical, superoxide anion radical, and hydroxyl radical. The antinociceptive activity was tested by acetic acid-induced writhing response, hot plate method, and tail flick method in albino rats. The anti-inflammatory potential of gels of ethanolic extract has been determined by using carrageenan-induced paw edema assay, formalin-induced paw edema assay, arachidonic acid-induced ear edema assay, and xylene-induced ear edema assay. The extract showed remarkable antioxidant activity in all models, comparable to the standard reference drug ascorbic acid. The ethanolic extract of Alocasia indica and its gels produced dose-dependent antinociceptive and anti-inflammatory activity, respectively. This finding suggests that ethanolic extract of A. indica possess potent antinociceptive and anti-inflammatory activity possibly due to its free radical scavenging properties.