Clinical pharmacokinetics of tenoxicam

Comparison of different nonsteroidal anti-inflammatory drugs for cesarean section: a systematic review and network meta-analysis

BACKGROUND

Cesarean section is associated with moderate to severe pain and nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly employed. The optimal NSAID, however, has not been elucidated. In this network meta-analysis and systematic review, we compared the influence of control and individual NSAIDs on the indices of analgesia, side effects, and quality of recovery.

METHODS

CDSR, CINAHL, CRCT, Embase, LILACS, PubMed, and Web of Science were searched for randomized controlled trials comparing a specific NSAID to either control or another NSAID in elective or emergency cesarean section under general or neuraxial anesthesia. Network plots and league tables were constructed, and the quality of evidence was evaluated with Grading of Recommendations Assessment, Development and Evaluation (GRADE) analysis.

RESULTS

We included 47 trials. Cumulative intravenous morphine equivalent consumption at 24 h, the primary outcome, was examined in 1,228 patients and 18 trials, and control was found to be inferior to diclofenac, indomethacin, ketorolac, and tenoxicam (very low quality evidence owing to serious limitations, imprecision, and publication bias). Indomethacin was superior to celecoxib for pain score at rest at 8-12 h and celecoxib + parecoxib, diclofenac, and ketorolac for pain score on movement at 48 h. In regard to the need for and time to rescue analgesia COX-2 inhibitors such as celecoxib were inferior to other NSAIDs.

CONCLUSIONS

Our review suggests the presence of minimal differences among the NSAIDs studied. Nonselective NSAIDs may be more effective than selective NSAIDs, and some NSAIDs such as indomethacin might be preferable to other NSAIDs.

Toxic Epidermal Necrolysis, A Serious Side Effect of Tenoxicam Use: A Case Report

Tenoxicam, a selective cyclooxygenase (COX)-2 inhibitor, has potent analgesic and anti-inflammatory effects and is frequently used for out-of-hospital pain control. Even though other non-steroidal anti-inflammatory drugs were incriminated in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) appearance, the literature is scarce regarding this agent. We report a case of tenoxicam-induced toxic epidermal necrolysis, detailing the multidisciplinary approach in a patient presenting skin detachment of 90% of the total body surface area, with concomitant ocular, oral, nasal, and vaginal mucosae involvement. A skin biopsy confirmed the diagnosis. The immediate cessation of the incriminated drug and rapid initiation of systemic steroids, along with topical therapies, and isolation into a specific environmental condition to limit skin infection were the cornerstones of therapeutic management. The patient was discharged with skin hyperpigmentation area and mild anxiety as long-term sequels. This report emphasized that severe or complicated cases should be transferred to a specialized burn center to reduce mortality risk and long-term morbidity.

Comparison of intravenous ibuprofen and tenoxicam efficiency in ankle injury: a randomized, double-blind study

BACKGROUND AND AIM

Pain after soft tissue injuries in and around the ankle is a troublesome process in terms of patient comfort and mobilization. The aim of this study was to compare the analgesic efficacy of intravenous ibuprofen and intravenous tenoxicam in patients with acute musculoskeletal pain due to ankle injury.

METHODS

We conducted a prospective, double-blind, randomized controlled study in a tertiary hospital. The patients were divided into two groups as those administered IV 400 mg ibuprofen and IV 20 mg tenoxicam. After the treatment of the patients, visual analog scale (VAS) scores were recorded at 15, 30, 60, and 120 min. VAS scores were compared with the effectiveness of drugs, their side effects, and the need for rescue drugs.

RESULTS

One hundred and twenty-four patients were included in the study. There were 62 patients in the tenoxicam group and 62 patients in the ibuprofen group. When VAS scores were compared, it was found that the VAS scores of the ibuprofen group were statistically significantly lower (p < 0.001). When the ΔVAS scores were compared, it was observed that the ΔVAS scores of the ibuprofen group were statistically significantly higher from 30 min (p < 0.001). There was a statistically significant difference in favor of ibuprofen between the two drug groups in terms of the need for rescue analgesics (p < 0.001). Conclusıon. The analgesic efficacy of intravenous ibuprofen and tenoxicam is equal after an ankle injury. However, after 30 min of drug administration, ibuprofen provides more effective analgesia than tenoxicam.

Hybrid Nanocomposites of Tenoxicam: Layered Double Hydroxides (LDHs) vs. Hydroxyapatite (HAP) Inorganic Carriers

The search for effective systems to facilitate the release of poorly bioavailable drugs is a forefront topic for the pharmaceutical market. Materials constituted by inorganic matrices and drugs represent one of the latest research strategies in the development of new drug alternatives. Our aim was to obtain hybrid nanocomposites of Tenoxicam, an insoluble nonsteroidal anti-inflammatory drug, with both layered double hydroxides (LDHs) and hydroxyapatite (HAP). The physicochemical characterization on the base of X-ray powder diffraction, SEM/EDS, DSC and FT-IR measurements was useful to verify the possible hybrids formation. In both cases, the hybrids formed, but it seemed that the drug intercalation in LDH was low and, in fact, the hybrid was not effective in improving the pharmacokinetic properties of the drug alone. On the contrary, the HAP-Tenoxicam hybrid, compared to the drug alone and to a simple physical mixture, showed an excellent improvement in wettability and solubility and a very significant increase in the release rate in all the tested biorelevant fluids. It delivers the entire daily dose of 20 mg in about 10 min.

Chitosan Encapsulated Meloxicam Nanoparticles for Sustained Drug Delivery Applications: Preparation, Characterization, and Pharmacokinetics in Wistar Rats

Meloxicam (MLX) is currently used in the therapeutic management of both acute and chronic inflammatory disorders such as pain, injuries, osteoarthritis, and rheumatoid arthritis in both humans and animals. Gastrointestinal toxicity and occasional renal toxicity were observed in patients taking it for a long-term period. Meloxicam's late attainment of peak plasma concentration results in a slow onset of action. The goal of the current study was to prepare and characterize chitosan encapsulated meloxicam nanoparticles (CEMNPs) with high bioavailability and less gastro intestinal toxicity in order to prevent such issues. The size of the prepared CEMNPs was approximately 110-220 nm with a zetapotential of +39.9 mV and polydispersity index of 0.268, suggesting that they were uniformly dispersed nanoparticles. The FTIR and UV-Vis spectroscopy have confirmed the presence of MLX in the prepared CEMNPs. The pharmacokinetics have been studied with three groups of male Wistar rats receiving either of the treatments, viz., 4 mg·kg-1 of MLX and 1 or 4 mg·kg-1 of CEMNPs. Plasma samples were collected until 48 h post administration, and concentrations of MLX were quantified by using reverse (C18) phase HPLC. Non-compartmental analysis was applied to determine pharmacokinetic variables. Upon oral administration, the maximum concentration (Cmax) was reached in 4 h for CEMNPs and 6 h for MLX. The mean area under the plasma MLX concentration-time curve from 'zero' to infinity (AUC0-∞), half-life (t1/2β), and mean resident time (MRT) of 1 mg·kg-1 of CEMNPs was 1.4-, 2-, and 1.8-fold greater than 4 mg·kg-1 of MLX. The prepared CEMNPs demonstrated quicker absorption and prolonged release along with a significant improvement in the bioavailability of MLX, paving a prospective path for the development of drugs with enhanced bioavailability with less side effects.

Impact of Non-Steroidal Anti-Inflammatory Drugs on Recurrence and Survival after Melanoma Surgery: A Cohort Study

The aim of the study was to investigate if there was an association between intraoperative NSAID use and recurrence or survival. A cohort of patients who underwent sentinel lymph node biopsy for the treatment of cutaneous melanoma was retrospectively recruited. After applying inclusion and exclusion criteria, 516 were included (NSAIDs = 307). The 10-year melanoma-specific survival was 63.2%. Log-rank test showed no statistically significant differences in time to treatment failure, melanoma-specific survival, disease-free survival, and overall survival between the study groups. The current study did not support the use of intraoperative NSAIDs in preventing death or recurrence in patients with melanoma.

Oral Administration System Based on Meloxicam Nanocrystals: Decreased Dose Due to High Bioavailability Attenuates Risk of Gastrointestinal Side Effects

Meloxicam (MLX) is widely applied as a therapy for rheumatoid arthritis (RA); however, it takes far too long to reach its peak plasma concentration for a quick onset effect, and gastrointestinal toxicity has been observed in RA patients taking it. To solve these problems, we designed MLX solid nanoparticles (MLX-NPs) by the bead mill method and used them to prepare new oral formulations. The particle size of the MLX-NPs was approximately 20-180 nm, and they remained in the nano-size range for 1 month. The tmax of MLX-NPs was shorter than that of traditional MLX dispersions (MLX-TDs), and the intestinal penetration of MLX-NPs was significantly higher in comparison with MLX-TDs (P < 0.05). Caveolae-dependent endocytosis (CavME), clathrin-dependent endocytosis (CME), and micropinocytosis (MP) were found to be related to the high intestinal penetration of MLX-NPs. The area under the plasma MLX concentration-time curve (AUC) for MLX-NPs was 5-fold higher than that for MLX-TDs (P < 0.05), and the AUC in rats administered 0.05 mg/kg MLX-NPs were similar to rats administered the therapeutic dose of 0.2 mg/kg MLX-TDs. In addition, the anti-inflammatory effect of the MLX-NPs was also significantly higher than that of MLX-TDs at the corresponding dose (P < 0.05), and the therapeutic effect of 0.2 mg/kg MLX-TDs and 0.05 mg/kg MLX-NPs in adjuvant-induced arthritis (AA) rats showed no difference. Furthermore, the gastrointestinal lesions in AA rats treated repetitively with 0.05 mg/kg MLX-NPs were fewer than in rats receiving 0.2 mg/kg MLX-TDs (P < 0.05). In conclusion, we demonstrate that MLX solid nanoparticles allow a quick onset of therapeutic effect and that three endocytosis pathways, CavME, CME, and MP, are related to the high absorption of solid nanoparticles. In addition, we found that MLX solid nanoparticles make it possible to reduce the amount of orally administered drugs, and treatment with low doses of MLX-NPs allows RA therapy without intestinal ulcerogenic responses to MLX. These findings are useful for designing therapies for RA patients.

PEGylated meloxicam-loaded nanocapsules reverse in vitro damage on caspase activity and do not induce toxicity in cultured human lymphocytes and mice

Meloxicam is an anti-inflammatory drug that has a potential protective effect in many common diseases. However, this molecule is quickly eliminated from the body due to it short half-life. One way to overcome this problem is to incorporate meloxicam into lipid-core nanocapsules which may increase it anti-inflammatory effects. In view of this, the objective of this work was to evaluate the potential toxicity and safety of these novel nanomaterials both in vitro and in vivo. Here, we evaluated the effects of uncoated meloxicam-loaded nanocapsules (M-NC), uncoated and not loaded with meloxicam or blank (B-NC), PEGylated meloxicam-loaded lipid-core nanocapsules (M-NCPEG), blank PEGylated lipid-core nanocapsules (B-NCPEG) and free meloxicam (M-F) in vitro through the analysis of cell viability, caspase activity assays and gene expression of perforin and granzyme B. Meanwhile, the in vivo safety was assessed using C57BL/6 mice that received nanocapsules for seven days. Thus, no change in cell viability was observed after treatments. Furthermore, M-NC, M-NCPEG and M-F groups reversed the damage caused by H₂O₂ on caspase-1, 3 and 8 activities. Overall, in vivo results showed a safe profile of these nanocapsules including hematological, biochemical, histological and genotoxicity analysis. In conclusion, we observed that meloxicam nanocapsules present a safe profile to use in future studies with this experimental protocol and partially reverse in vitro damage caused by H₂O₂.

The use of tenoxicam to prevent symptoms of discomfort induced by vagotonia during uterus manipulation in cesarean sections

PURPOSE

Symptoms such as nausea, vomiting, tightness of the chest, bradycardia, and shoulder or abdominal discomfort, caused by vagotonia occurring during uterus manipulation, have concerned healthcare professionals for some time. Patients sometimes report these symptoms when undergoing spinal anesthesia for cesarean sections (CSs). We designed a prospective, double-blind study to investigate the effectiveness of tenoxicam in preventing these symptoms of discomfort.

METHODS

A total of 105 American Society of Anesthesiologists (ASA) class I-II nulliparous pregnant women, who were scheduled for a CS, were enrolled into this prospective, double-blind study. Spinal anesthesia was conducted to reach a peak dermatome level of no more than T3. The 100 patients were randomly divided into 2 groups having completed study course: Group T (N = 50) received a 20 mg dose of tenoxicam in 5 mL of normal saline (NS) immediately after skin incision and Group N (N = 50) only received 5 mL NS. The incidence and severity of the symptoms experienced by the patients were recorded by a nurse anesthetist who was blinded to the injection regimen the patients were receiving. A chi-square test was used for statistical analysis t test and P < .05 was defined as significant.

RESULTS

The incidence and degree of severity of nausea and vomiting were same in both the groups. The incidence and degree of severity of bradycardia, nausea, vomiting, tightness of the chest, shoulder discomfort, and abdominal discomfort were lower in Group T than in Group N.

CONCLUSION

Tenoxicam might theoretically block the parasympathetic vagus pathway and decrease the visceral pain or visceral-specific symptoms, alleviating the symptoms caused by vagotonia. However, the prophylactic effect of tenoxicam in reducing the incidence and severity of nausea and vomiting was not statistically significant. This could be because nausea and vomiting are not solely caused by vagotonia, but also by other mechanisms.

Comparison of the effectivity of oral and intra-articular administration of tenoxicam in patients with knee osteoarthritis

BACKGROUND AND OBJECTIVES

Tenoxicam is widely used in osteoarthritis treatment and we aimed to compare the effectivity of oral and intra-articular administration of tenoxicam in osteoarthritis treatment.

METHODS

This study was performed between 2011 and 2012 by retrospectively analyzing and comparing the findings of 60 patients who were clinically and radiologically diagnosed with knee degenerative osteoarthritis in Bünyan state hospital pain policlinic. 60 patients included in the study were divided into two groups. The first group (tenoxicam IA, n=30) included patient findings of those subjected to intra-articular injection of 20mg tenoxicam to the knee once a week for three weeks and the second group (oral tenoxicam, n=30) included patients who were administered 20mg oral tenoxicam once a day for three weeks. All patients were clinically evaluated pre-treatment and in the 1st week, 1st month and 3rd month post-treatment according to specified criteria.

RESULTS AND CONCLUSIONS

Twenty two of 60 patients included in the study were male and 38 were female. In both groups significant improvements were detected in all of the observed parameters: visual analog scale, Western Ontario McMaster Osteoarthritis Index (pain, physical activity, knee stiffness) and Lequesne index scores and in the evaluations performed in 1st week, 1st month and 3rd month with respect to pre-treatment values. Besides, a better compliance to treatment and gastrointestinal system tolerability in tenoxicam IA group was also observed. Intra-articular tenoxicam administration could be thought as an alternative treatment method in patients with knee osteoarthritis who cannot use oral tenoxicam especially due to systemic gastrointestinal system side effects and those who have difficulties in adapting to treatment.

FXR antagonism of NSAIDs contributes to drug-induced liver injury identified by systems pharmacology approach

Non-steroidal anti-inflammatory drugs (NSAIDs) are worldwide used drugs for analgesic, antipyretic, and anti-inflammatory therapeutics. However, NSAIDs often cause several serious liver injuries, such as drug-induced liver injury (DILI), and the molecular mechanisms of DILI have not been clearly elucidated. In this study, we developed a systems pharmacology approach to explore the mechanism-of-action of NSAIDs. We found that the Farnesoid X Receptor (FXR) antagonism of NSAIDs is a potential molecular mechanism of DILI through systematic network analysis and in vitro assays. Specially, the quantitative real-time PCR assay reveals that indomethacin and ibuprofen regulate FXR downstream target gene expression in HepG2 cells. Furthermore, the western blot shows that FXR antagonism by indomethacin induces the phosphorylation of STAT3 (signal transducer and activator of transcription 3), promotes the activation of caspase9, and finally causes DILI. In summary, our systems pharmacology approach provided novel insights into molecular mechanisms of DILI for NSAIDs, which may propel the ways toward the design of novel anti-inflammatory pharmacotherapeutics.

The pain management in orthodontics

Pain and discomfort are the frequent side-effects of the orthodontic therapy with fixed appliances. The people who experience orthodontic pain are likely to self-medicate with nonprescription pain relievers before seeing the dentist. It is imperative for an orthodontist to address questions that might arise in a clinical setting from the viewpoint of the clinicians and the patients/parents. This article will provide an overview of the current management strategies which are employed for alleviating orthodontic pain.

Systematic evaluation of 640 FDA drugs for their effect on CD4⁺Foxp3⁺ regulatory T cells using a novel cell-based high throughput screening assay

Regulatory T cells (Treg), which play a pivotal role in maintaining immune homeostasis by suppressing the proliferation of effector T cells, have great therapeutic potential for autoimmune diseases and transplantation. However, progress on their clinical application has been hampered by the lack of high throughput screening (HTS) strategies for the systematic and rapid evaluation of existing drugs and the identification of novel drug candidates. In this report, we present an innovative in vitro HTS assay using CD4⁺ T cells from Foxp3-GFP transgenic mice that specifically express the GFP signal in Foxp3⁺ Treg cells detectable by FACS analysis in a high throughput manner. Systematic evaluation of 640 FDA-approved drugs revealed that 70 drugs increased the number of Treg cells with suppression function only in the presence of TGFβ, 75 drugs increased Treg numbers even in the absence of TGFβ, and 32 drugs increased Treg numbers synergistically with TGFβ. The identified Treg-promoting drugs include those previously known to induce Treg (rapamycin and retinoic acid), statins, glucocorticoids and drugs in many other categories. Furthermore, Treg cells cultured with the identified drugs possess surface and intracellular markers characteristic of natural Treg cells and possess suppressive function. These results suggest that this Treg HTS assay can be used to screen compound libraries to identify novel chemical entities for Treg-based immune therapies.

Single dose oral tenoxicam for acute postoperative pain in adults

BACKGROUND

Tenoxicam is a non-steroidal anti-inflammatory drug (NSAID) licensed for use in rheumatic disease and other musculoskeletal disorders in the UK, and is widely available in other countries worldwide. This review sought to evaluate the efficacy and safety of oral tenoxicam in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral tenoxicam in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched The Cochrane Library (Issue 1, 2009), MEDLINE (March 2009); EMBASE via Ovid (March 2009); the Oxford Pain Relief Database.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral tenoxicam for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with tenoxicam experiencing least 50% pain relief over 4 to 6 hours, using validated equations. The number needed to treat to benefit (NNT) was calculated using 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

Not one of sixteen studies identified by the searches and examined in detail studied oral tenoxicam in patients with established postoperative pain and therefore no results are available.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral tenoxicam in acute postoperative pain, its use in this indication is not justified at present. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes which are effective, there is no urgent research agenda for this particular drug.

Tenoxicam controls pain without altering orthodontic movement of maxillary canines

OBJECTIVES

To study the efficacy of tenoxicam for pain control, its potential for preemptive analgesia, and its influence on the orthodontic movement of upper canine teeth.

DESIGN

This was a randomized controlled double-blind cross-over study. The patients were divided into three groups. Two groups received tenoxicam in daily doses of 20 mg orally for 3 days. Group A received the first dose of the drug before orthodontic activation and group B, just afterwards. Group C (control) received a placebo for 3 days. All groups had access to 750 mg of paracetamol up to four times a day. Three orthodontic activations were performed at 30-day intervals. Each patient belonged to two different groups. Pain intensity was assessed using a descriptive Pain Scale and a Visual Analog Scale.

SETTING AND SAMPLE POPULATION

Private clinic; 36 patients undergoing bilateral canine tooth retraction.

RESULTS

The statistical analysis did not show any difference in movement between the active groups and the control at any time. There was no statistical difference between the groups that received tenoxicam. Pain intensity in these groups was lower than in the placebo group. The difference in pain intensity between the active groups and the control was greatest at the assessment made 12 h after activation and it tended to zero, 72 h after activation.

CONCLUSIONS

Tenoxicam did not influence orthodontic movement of the upper canines. It was effective for pain control and did not present any preemptive analgesic effect.

Prevention of adhesion formation in a laparoscopic mouse model should combine local treatment with peritoneal cavity conditioning

BACKGROUND

Adhesion formation results from a series of local events at the trauma site. This process can be enhanced by factors derived from the peritoneal cavity such as mesothelial cell hypoxia (pneumoperitoneum with pure CO(2)), reactive oxygen species (pneumoperitoneum with more than 4% oxygen), desiccation and mesothelial trauma produced through manipulation. Adhesion prevention, therefore, should combine local treatment while minimizing adverse peritoneal factors through conditioning of the pneumoperitoneum.

METHODS

In a laparoscopic mouse model, adhesion induction comprised a mechanical lesion together with a humidified pneumoperitoneum for 60 min with pure CO(2) at 37 degrees C. Adhesion prevention consisted of a combination of treatments known to reduce adhesions, i.e. pneumoperitoneum with CO(2) with the addition of 3-4% O(2), reduction of body temperature (BT) to 32 degrees C and application of antiadhesion products such as anti-inflammatory drugs (dexamethasone, nimesulide), calcium-channel blockers (diltiem), surfactants (phospholipids), barriers (Hyalobarrier gel), reactive oxygen species scavengers (superoxide dismutase and ascorbic acid) and recombinant plasminogen activator.

RESULTS

The addition of 3% O(2) to the pneumoperitoneum or a lower BT decreased adhesions by 32% or 48%, respectively (P < 0.05, Wilcoxon), but were without additional effects when combined. In addition, if dexamethasone or Hyalobarrier((R)) gel were administrated, the total reduction was 76% (P = 0.04) or 85% (P < 0.02), respectively.

CONCLUSIONS

Combining pneumoperitoneum conditioning together with dexamethasone or a barrier resulted in significant adhesion reduction in a laparoscopic mouse model.

Pharmacokinetics of formulated tenoxicam transdermal delivery systems

To investigate the feasibility of developing a new tenoxicam transdermal delivery system (TDS), the pharmacokinetics of tenoxicam from various formulated TDS were evaluated and compared with values following oral administration of tenoxicam and with application of a piroxicam plaster (Trast) marketed in Korea. Based on previous in-vitro study results, a mixture of diethylene glycol monoethyl ether (DGME) and propylene glycol monolaurate (PGML) (40:60) was used as a vehicle, and caprylic acid, capric acid, lauric acid, oleic acid or linoleic acid (each at 3%) was added as an enhancer. Triethanolamine (5%) was used as a solubilizer, and Duro-Tak 87-2510 as a pressure-sensitive adhesive. Among these fatty acids used for the formulation of tenoxicam TDS, caprylic acid showed the greatest enhancing effect; the area under the plasma concentration-time profile (AUC) decreased in the order of caprylic acid>linoleic acid>or=oleic acid>lauric acid>capric acid. Compared with oral administration, maximum plasma concentration (Cmax) was significantly lower, and time to reach Cmax (Tmax) delayed with all formulated tenoxicam TDS. All formulated TDS resulted in a lower AUC than with the oral formulation, except for TDS containing caprylic acid, although the difference was statistically significant only with capric acid. The AUC for all the formulated tenoxicam TDS was significantly higher than that of the piroxicam plaster; TDS with caprylic acid increased AUC 8.53-fold compared with the piroxicam plaster. Even though the Tmax of tenoxicam TDS was not significantly different from that of the piroxicam plaster, Cmax was higher; formulations containing caprylic acid and linoleic acid increased Cmax by 7.39- and 8.76-fold, respectively. In conclusion, a formulation containing 1.5 mL DGME-PGML (40:60) with 3% caprylic acid and 5% triethanolamine mixed with 6 g Duro-Tak 87-2510 could be a good candidate for developing a new tenoxicam TDS to maintain a comparable extent of absorption to oral delivery while attaining a prolonged effect with fewer toxic events.

Effect of reactive oxygen species scavengers, antiinflammatory drugs, and calcium-channel blockers on carbon dioxide pneumoperitoneum-enhanced adhesions in a laparoscopic mouse model

BACKGROUND

Postoperative adhesions are a clinical problem. They can cause female infertility, intestinal obstruction, chronic pelvic pain, and difficulties at the time of reoperation. A variety of approaches described to prevent adhesions have shown variable and inconsistent results. Therefore, this study aimed to evaluate most known substances in a laparoscopic mouse model to obtain quantitative and comprehensive information on adhesion prevention. Specifically, this first study aimed to investigate the effects of reactive oxygen species (ROS) scavengers, antiinflammatory agents, and a calcium-channel blocker on pneumoperitoneum-enhanced adhesions.

METHODS

Adhesions were induced during laparoscopy in BALB/c female mice by creation of a bipolar lesion. Carbon dioxide (CO2) pneumoperitoneum was maintained for 60 min using humidified CO2. Six experiments were conducted to evaluate the effects of ROS scavengers (superoxide dismutase [SOD], catalase, melatonin, and ascorbic acid), antiinflammatory agents (dexamethasone, tenoxicam, ibuprofen, parecoxib, nimesulide, anti-tumor necrosis factor [TNF]-alpha), and a calcium-channel blocker (diltiazem). Adhesions were scored after 7 days during laparotomy.

RESULTS

Adhesions were reduced by SOD (p < 0.01, proc general linear methods (GLM) of experiments 1 and 2), diltiazem (p = 0.05, Wilcoxon), and dexamethasone (p < 0.03), but not by nonsteroidal antiinflammatory drugs (NSAIDs) nor by anti-TNF-alpha. When all the experiments were grouped for analysis, adhesions also decreased with one and three doses of SOD (p < 0.01 and p < 0.01, respectively) and with one and three doses of ascorbic acid (p < 0.02 and p = 0.05, respectively).

CONCLUSIONS

These experiments confirm that SOD, diltiazem, and dexamethasone can decrease adhesion formation. The absence of effect from the other antiinflammatory drugs and anti-TNF-alpha is surprising.

[Clinical pharmacogenomics for CYP2C8 and CYP2C9: general concepts and application to the use of NSAIDs]

OBJECTIVE

To study the major mutations in genes CYP2C8 and CYP2C9, their frequency in populations of diverse ethnical descent, their analysis methods, and the major drugs with affected metabolism, with a special emphasis on NSAIDs.

METHOD

Repeated searches of Pubmed (January 1966-January 2006) and Scholar Google were performed. All searches were restricted to studies in humans, and papers not written in Spanish or English were excluded.

RESULTS

Ten allelic variants of CYP2C8 and 24 of CYP2C have been reported. Not all of them exert a relevant effect on drug metabolism. In Caucasians 22% of CYP2C8 genes and 31% of CYP2C9 genes have mutations. In Asians fewer than 1% and nearly 3% are mutated, respectively. Major identification methods include endonuclease digestion, PCR, pyrosequencing, and microarrays. Not all NSAIDs are exclusive substrates for CYP2C8/9. The usefulness of allelic variant analysis varies with each individual drug. The risk for digestive hemorrhage associated with the CYP2C9 genotype is particularly relevant when using aceclofenac, celecoxib, diclofenac, ibuprofen, indomethacin, lornoxicam, piroxicam, or naproxen.

CONCLUSIONS

Although CYP2C8/9 activity plays an essential role in the metabolism of and clinical response to many NSAIDs, the use of pharmacogenomic techniques is not equally useful for all these drugs.

Fast RPLC-UV method on short sub-two microns particles packed column for the assay of tenoxicam in plasma samples

An extraction-less sample preparation technique followed by a RPLC-UV method on sub-two microns particles packed short column were used for the assay of tenoxicam in plasma samples. Protein precipitation was made by means of trichloroacetic acid addition. Supernatant was injected to the chromatographic column without any further pH adjustment. The mobile phase consisted in a mixture of acetonitrile and aqueous 0.1% phosphoric acid, at 2 mL/min flow rate and gradient elution. The Zorbax SB-C18 column (50 mm length, 4.6 mm internal diameter and 1.8 microm particle size) was thermostated at 60 degrees C. The mobile phase gradient composition program allowed separation of tenoxicam and piroxicam (internal standard), column clean-up and re-equilibration within 4 min. UV detection was achieved at 368+/-10 nm. The method is characterized by a low limit of quantitation of 25 ng/mL for tenoxicam, with a linearity interval up to 5500 ng/mL. The use of a low volume detection cell and detector high frequency data acquisition rate produced high precision and accuracy through a whole bioequivalence study of tenoxicam in two commercially available tablet formulations, after a single oral administration dose. Full method validation is presented. The high throughput characteristic of the proposed method allowed full validation and bioanalytical study completion within a 96 h period.

Comparison of intra-articular tenoxicam and oral tenoxicam for pain and physical functioning in osteoarthritis of the knee

This study was designed to compare efficacy of local administration of a nonsteroidal anti-inflammatory drug with systemic administration in patients with osteoarthritis (OA) of the knee. For this purpose, intra-articular tenoxicam and oral tenoxicam therapies were applied and the improvement in control of pain and physical functioning were evaluated. A total of 69 patients with OA of the knee were randomized into three groups. Patients in the first group (41 knees of 23 patients) were treated for 1-3 weeks with once weekly intra-articular injection of tenoxicam 20 mg. Patients in the second group (45 knees of 26 patients) received 20 mg/day tenoxicam orally for 3 weeks and only physical exercises were applied to the third group (32 knees of 20 patients). Physical examination of the knee joint, Western Ontario and McMaster Universities Index and the Lequesne Algofunctional Index were used as outcome measurements at baseline, and the 1st, 3rd and 6th months. More significant improvement in pain and disability parameters was observed in groups 1 and 2 than group 3 compared with baseline measures. Among the patients' responses a few of the differences were statistically significant, more in favour of tenoxicam, and tenoxicam seemed to be superior to exercise alone especially at the final evaluation. There was no significant difference between the oral and intra-articular tenoxicam treatment regimens. The results of this study showed that treatment of OA of the knee with intra-articular tenoxicam is as effective as that with oral tenoxicam. It can be thought that intra-articular administration can be preferred to oral therapy due to minimal possibility of systemic side effects.

IMPACT OF CYP2C9 GENOTYPE ON PHARMACOKINETICS: ARE ALL CYCLOOXYGENASE INHIBITORS THE SAME?: TABLE 1

The market withdrawals of rofecoxib (Vioxx) and valdecoxib (Bextra) have focused considerable attention on the side effect profiles of cyclooxygenase (COX) inhibitors. As a result, attempts will be made to identify risk factors in the hope that physicians might be able to ensure patient safety. At first glance, CYP2C9 genotype might be considered a risk factor because many COX inhibitors are CYP2C9 substrates in vitro. This observation has led some to hypothesize that a reduction in clearance, in subjects expressing variant forms of the enzyme (e.g., CYP2C9*1/*3 or CYP2C9*3/*3 genotype), will lead to increased exposure and a greater risk of cardiovascular or gastrointestinal side effects. For any drug, however, one has to consider all clearance pathways. Therefore, a number of COX inhibitors were surveyed and it was determined that CYP2C9 plays a relatively minor role in the overall clearance (<or=20% of the dose) of sulindac, naproxen, ketoprofen, diclofenac, rofecoxib, and etoricoxib. CYP2C9 genotype would have no clinically meaningful impact on the pharmacokinetics of these drugs. In contrast, CYP2C9 genotype is expected to impact the clearance of ibuprofen, indomethacin, flurbiprofen, celecoxib, valdecoxib, lornoxicam, tenoxicam, meloxicam, and piroxicam. However, even when CYP2C9 is a major determinant of clearance, it is necessary to consider CYP2C8 genotype (e.g., ibuprofen) and, possibly, CYP3A4 activity (e.g., celecoxib, valdecoxib, and meloxicam) also.

Pharmacokinetics of lumiracoxib in plasma and synovial fluid

BACKGROUND

Lumiracoxib is a new cyclo-oxygenase-2 (COX-2) selective inhibitor in development for the treatment of rheumatoid arthritis, osteoarthritis and acute pain.

OBJECTIVE

To investigate the pharmacokinetics of lumiracoxib in plasma and knee joint synovial fluid from patients with rheumatoid arthritis.

DESIGN

Open-label multiple-dose study evaluating the steady-state pharmacokinetics of lumiracoxib in plasma and synovial fluid after 7 days of treatment with lumiracoxib 400 mg once daily.

PATIENT POPULATION

Males and females aged 18-75 years with rheumatoid arthritis, having moderate to significant synovial fluid effusion of the knee.

OUTCOME MEASURES

Following a 7-day washout period for previous nonsteroidal anti-inflammatory drugs, 22 patients (17 female, 5 male) received lumiracoxib 400 mg once daily for seven consecutive days. On day 7, following an overnight fast, a final dose of lumiracoxib was administered and serial blood and synovial fluid samples were collected for up to 28 hours. Lumiracoxib and its metabolites (4'-hydroxy-lumiracoxib and 5-carboxy-4'-hydroxy-lumiracoxib) were measured by validated high performance liquid chromatography-mass spectrometry methods. The steady-state pharmacokinetics of lumiracoxib were evaluated in plasma and synovial fluid by both a population pharmacokinetic model and noncompartmental analysis.

RESULTS

Lumiracoxib was rapidly absorbed (peak plasma concentration at 2 hours) and the terminal elimination half-life in plasma was short (6 hours). Lumiracoxib concentrations were initially higher in plasma than in synovial fluid; however, from 5 hours after administration until the end of the 28-hour assessment period, concentrations of lumiracoxib were higher in synovial fluid than in plasma. Peak drug concentration in synovial fluid occurred 3-4 hours later than the peak plasma concentration. The mean steady-state trough concentration of lumiracoxib in synovial fluid (454 microg/L) was approximately three times higher than the mean value in plasma (155 microg/L), and the area under the concentration-time curve from 12 to 24 hours after administration was 2.6-fold higher for synovial fluid than for plasma. Median lumiracoxib protein binding was similar in plasma and synovial fluid (range 97.9-98.3%). Concentrations of 4'-hydroxy-lumiracoxib, the active COX-2 selective metabolite, remained low in comparison with parent drug in both plasma and synovial fluid. The concentration of lumiracoxib in synovial fluid at 24 hours after administration would be expected to result in substantial inhibition of prostaglandin E(2) formation.

CONCLUSION

The kinetics of distribution of lumiracoxib in synovial fluid are likely to extend the therapeutic action of the drug beyond that expected from plasma pharmacokinetics. These data support the use of lumiracoxib in a once-daily regimen for the treatment of rheumatoid arthritis.

Differential analgesic effect of tenoxicam on the wound pain and uterine cramping pain after cesarean section

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to enhance opioid analgesia in the acute pain service. The question, however, of whether NSAIDs produce a similar extent of potentiation among different types of pain, has not been thoroughly investigated.

MATERIALS AND METHODS

A randomized, placebo-controlled, double-blind study was performed to characterize the analgesic effect of tenoxicam, a long-acting NSAID, on resting wound pain, evoked wound pain, and uterine cramping pain after cesarean section. Saline (n = 48) or 20 mg tenoxicam (n = 45) was intravenously injected immediately after clamping the umbilical cord. All patients were instructed to obtain maximal postoperative analgesia by intravenous patient-controlled morphine. RESULTS Tenoxicam profoundly reduced the intensity of uterine cramping pain (3.6 [2.0-5.6] versus 5.5 [3.4-6.6]; p < 0.01) but had no additional effect on wound pain at rest, with movement, changing position, sitting, and walking. Intraoperative injection of 20 mg tenoxicam decreased the demand ratio for patient-controlled analgesia (PCA) and 24-hour morphine consumption by approximately 30%.

CONCLUSIONS

The data show that tenoxicam potentiates opioid analgesic effect on the somatic and visceral types of pain to different extents, and they suggest that intraoperative injection of 20 mg tenoxicam is sufficient to enhance intravenous PCA morphine on uterine cramping pain for the first 24 hours after cesarean section.

Effect of vehicles and penetration enhancers on the in vitro percutaneous absorption of tenoxicam through hairless mouse skin

The effects of vehicles and penetration enhancers on the in vitro permeation of tenoxicam from saturated solutions through dorsal hairless mouse skin were investigated. Various types of vehicles, including ester-, alcohol-, and ether-types and their mixtures, were used as vehicles, and then a series of fatty acids and amines were employed as enhancers, respectively. Even though the fluxes of tenoxicam from saturated pure vehicles were generally low (0.1-1.1 microg/cm2 per h), the skin permeability of tenoxicam was significantly increased by the combination of diethylene glycol monoethyl ether (DGME) and propylene glycol monolaurate (PGML) or propylene glycol monocaprylate (PGMC); the highest fluxes were achieved at 40% of DGME in both of the two cosolvents. The marked synergistic enhancement was also obtained by using propylene glycol (PG)-oleyl alcohol (OAl) cosolvent. The greatest flux was attained by the addition of unsaturated fatty acids at 3% concentration to PG. But saturated fatty acids failed to show a significant enhancing effect. The enhancement factors with the addition of oleic acid (OA) or linoleic acid (LOA) to PG were 348 and 238, respectively. Tromethamine (TM) showed an enhancing effect by the increased solubility; however, triethanolamine (TEA) did not show a significant enhancing effect. Rather, it decreased the fluxes of tenoxicam when added to PG with fatty acids. The above results indicate that the combinations of lipophilic vehicles like OA, LOA or OAl and hydrophilic vehicles like PG can be used for enhancing the skin permeation of tenoxicam.

Interaction of tenoxicam with cyclodextrins and its influence on the in vitro percutaneous penetration of the drug

Solid complexes of tenoxicam (TEN) with cyclodextrins (CDs), in a 1:1 molar ratio, were obtained by the coprecipitation method and characterized by x-ray diffractometry, infrared spectroscopy, and differential scanning calorimetry. The binding capacity of the CDs with TEN was also demonstrated in aqueous solution and in water-propylene glycol mixtures. The purpose of this study was to determine the effect of CDs on the in vitro percutaneous penetration of TEN from carbopol gels, taking into account the role of the CD cavity size and the nature of the substituents. The effect of pretreatment was studied too. In vitro permeation experiments were carried out on Franz diffusion cells using cellulose nitrate membranes and abdominal rat skin. In these results, the release rates of the drug scarcely decreased when the CDs were added, probably because of a lower concentration of the free drug and an increased gel viscosity. However, it was also found that CDs, particularly gamma-CD and M-beta-CD, can improve slightly TEN absorption through the skin. Pretreatment studies with CDs, however, provided no effects on TEN permeation, but lag time was markedly reduced, suggesting a faster partitioning of TEN into the skin. Therefore, the use of pretreatment with CDs would be interesting when a quick action of the drug is desired.

Timing of pre-emptive tenoxicam is important for postoperative analgesia

PURPOSE

In this prospective randomized study, a comparison was made between the efficacy of 20 mg tenoxicam, administered either, 30 min preoperatively or at induction of anesthesia, for the relief of postoperative pain in patients undergoing ambulatory breast biopsy.

METHODS

Seventy-three patients were recruited and all received a standard anesthetic consisting of induction with 2 mg x kg(-1) propofol followed by 5 microg x kg(-1) alfentanyl. No premedication was administered and at the end of the procedure the wounds were infiltrated with 10 ml of bupivacaine (0.5%). Patients were randomized to receive 20 mg tenoxicam intraveneously either 30 min before surgery or at induction of anesthesia.

RESULTS

Demographic criteria were similar in both groups. There were differences in pain scores at 30, 60, 120 and 240 min postoperatively (VAS at 30 min 3.2 +/- 1.2 vs 5.5 +/- 1.8; P < 0.001: VAS at 60 min 1.8 +/- 1.2 vs 3.7 +/- 1.9; P < 0.001: VAS at 120 min 0.9 +/- 0.9 vs 1.7 +/- 1.0; P = 0.003: VAS at 240 min 0.5 +/- 0.5 vs 1.1 +/- 0.8; P < 0.001: Expressed as mean +/- SD). There was a difference in the number of patients requiring additional analgesia, in the first four hours postoperatively (12 (33%) vs 27 (73%); P = 0.001) and a difference in the time to additional analgesia in these patients (87.5 +/- 32.5 vs 55.0 +/- 26.8 min; P = 0.002).

CONCLUSION

Early administration of pre-emptive tenoxicam 30 min before induction of anesthesia improves postoperative analgesia in patients undergoing ambulatory breast biopsy.

Tenoxicam i.v. in major gynaecological surgery--pharmacokinetic, pain relief and haematological effects

This study compared postoperative analgesic dispensation and measures relating to haemostasis following intravenous administration, in a randomized double-blinded manner, of either placebo or tenoxicam 20 mg to 30 women presenting for major gynaecological oncology surgery under a standardized, combined epidural/general anaesthetic technique. Pharmacokinetic disposition of tenoxicam in this patient cohort was also described. There was no objective or subjective alteration in haemostatic function or increase in blood loss, nor any deviation from the normal range of values. Postoperative analgesia during the first 48 hours was delivered to achieve a VAS endpoint of less than five on leg-raising, by a combination of a nurse-controlled low-dose background epidural infusion and patient-administered epidural bolus. Greater VAS variability was observed during the first four postoperative hours (P = 0.08). The tenoxicam group self-administered significantly fewer epidural bolus doses to maintain satisfactory analgesia compared with the placebo group during the first 24 hours (P = 0.004) and 48 hours (P = 0.01) postoperatively. Similar differences between the groups in the total dose of the epidural bupivacaine/fentanyl mixture delivered were described (4 h: P = 0.148; 24 h: P = 0.033; 48 h: P = 0.001) (Figure 2). Despite surgery, transfusion and the use of a renal protective fluid administration strategy, tenoxicam disposition was not greatly different from that widely described for healthy volunteers. There were no significant side-effects and no adverse events attributable to tenoxicam. In this small study we have shown that tenoxicam administered preoperatively reduced the epidural analgesic requirements during the first 48 hours following major gynaecological surgery. There was no clinical or pathological evidence of haematological impairment following a single i.v. administration of tenoxicam 20 mg.

Tenoxicam i.v. for major gynaecological surgery--effects on renal function

Thirty women presenting for major gynaecological oncology surgery under a standardized, combined epidural/general anaesthetic technique received either placebo or tenoxicam 20 mg intravenously, in a randomized double-blinded manner prior to surgery. Plasma and urinary electrolytes, creatinine, prostaglandins PgE2 and PgF1 alpha, and thromboxane (TxB2) were collected 12 hours preoperatively and then for four days postoperatively. There were no significant differences in any of the measured parameters between the groups, at any of the measurement times. Mean (SD) creatinine clearance at baseline, 24 h and 48 h was 100.4 (29.7) and 86.9 (27.5), 128.1 (45.9) and 115.0 (40.3), 137.5 (50.7) and 121.6 (38.6) in the placebo and tenoxicam groups respectively (P = 0.28). Both groups required similar amounts of intraoperative ephedrine and intravenous fluids to maintain blood pressure. The minimal changes in plasma and renal parameters reflect predictable responses to major surgery and rehydration rather than any response to cyclooxygenase inhibition. This may underscore the importance of maintenance of blood pressure during the course of surgery and postoperative care, and perhaps the usefulness of a fluid loading regimen to preserve renal function during surgery. The predicted attenuation of renal prostaglandin-mediated protective mechanisms and enhancement of the catecholamine-mediated renal vasoconstriction by the use of a single 20 mg dose of tenoxicam in this study were not seen. Modulation of renal concentrating mechanisms or excretion of sodium and potassium by tenoxicam was not apparent and a large increase in study size would be required to detect a significant difference in these parameters as a consequence of the drug, over and above any changes in response to surgery and epidural anaesthesia.

Effects of intraperitoneal lidocaine combined with intravenous or intraperitoneal tenoxicam on pain relief and bowel recovery after laparoscopic cholecystectomy

BACKGROUND

Previous work has demonstrated that intraperitoneal (i.p.) lidocaine may provide analgesia after laparoscopic cholecystectomy. The aim of this prospective, randomized, double-blind study was to compare pain relief, recovery variables, and side effects after i.p. instillation of lidocaine plus tenoxicam given either i.v. or i.p. after laparoscopic cholecystectomy.

METHODS

Ninety patients were randomly allocated to one of three groups to receive either 200 ml normal saline i.p. and 2 ml of normal saline i.v. (saline group), 200 ml lidocaine 0.1% i.p. and 2 ml tenoxicam 20 mg i.v. (tenoxicam i.v. group), or 200 ml lidocaine 0.1% with 20 mg tenoxicam i.p. and 2 ml of normal saline i.v. (tenoxicam i.p. group). The i.p. instillation was made under the right diaphragm and on the gall bladder bed. VAS pain scores at rest, on movement and during coughing, were measured 2, 4, 6, 12, and 24 h after operation. The time to first demand of analgesia, total analgesic requirement, recovery variables, and side effects were investigated.

RESULTS

In the tenoxicam i.p. group, pain scores were significantly lower both at rest and on movement and analgesic consumption was reduced compared with the saline group (P<0.05). In the tenoxicam i.v. group, pain scores at rest were significantly lower compared with the saline group. Although recovery of bowel function was significantly faster in the tenoxicam i.p. group (P<0.05), there were no differences in any other recovery characteristics or incidence of nausea between the groups.

CONCLUSION

Combination of intraperitoneal lidocaine and tenoxicam provided better analgesia on movement, and faster return of bowel function compared with i.p. lidocaine and i.v. tenoxicam during the 24 h period after surgery.

Effect of tenoxicam on biochemical serum parameters of rats

Tenoxicam is a nonsteroidal analgesic of the oxicam group, which possesses both antipyretic and anti-inflammatory characteristics. The use of tenoxicam has recently increased and it is reported in the literature that treatments lasting between a few weeks to three months caused increases in serum alanine transferase (ALT), aspartate transferase (AST), gamma glutamyl transferase (GGT) and bilirubin in humans. Toxic dose treatments to rats caused alterations in renal parameters. To verify these observations, various biochemical parameters were examined following administration of nontoxic doses of tenoxicam to rats. Rats were divided into three groups. One group received tenoxicam 0.6 mg/kg/day; the second group received 1.2 mg/kg/day i.p. The control group received normal saline i.p. At the end of 15 days, blood samples from the animals' hearts were taken for routine biochemical tests. No statistically significant changes were observed in serum urea, uric acid, creatinine, electrolytes, ALT, AST, total protein, bilirubin or glucose levels between the treatment groups and control groups. Increases in GGT levels were found to be statistically significant in both of the treatment groups compared with the control group.

Effect of i.v. tenoxicam during caesarean delivery on platelet activity

BACKGROUND

Non-steroidal anti-inflammatory drugs inhibit platelet aggregation and prolong bleeding time in healthy subjects. We have studied the effect of i.v. tenoxicam during caesarean delivery on skin bleeding time, operative, and postoperative blood loss, and beta-thromboglobulin and platelet factor 4 as specific molecular markers for platelet activity.

METHODS

Fifty women were studied. Twenty-five were given tenoxicam 20 mg i.v. 10 min before induction of general anaesthesia, and 25 formed a control group. Skin bleeding time and platelet markers were determined the day before and 1 h after induction of anaesthesia.

RESULTS

In the tenoxicam group, there was an slight increase in skin bleeding time with no statistically significant changes in platelet marker levels. In the control group, platelet markers increased 1 h after surgery. The surgeon's assessment of uterine relaxation, using a visual analogue score, operating theatre blood loss, and the frequency of bleeding over 24 h after operation, showed no significant difference between the two groups.

CONCLUSION

During caesarean delivery i.v. tenoxicam causes a slight increase in bleeding time with no significant changes in platelet marker levels.

The effect of tenoxicam on intraperitoneal adhesions and prostaglandin E2 levels in mice

We determined whether tenoxicam administered intraperitoneally in the preoperative period had an effect on the development of postoperative intraabdominal adhesions (IAA). For this purpose, 100 albino mice were divided into four random groups. Mice in Group 1 were given only 1 mL of 0.9% NaCl intraperitoneally, whereas in Group 2, 1 mL of tenoxicam (150 microg = 5 mg/kg) was administered. After the induction of anesthesia, a median laparotomy was performed, and the bowels were traumatized by touching them with powdered gloves before the incision was closed in Groups 3 and 4. Intraperitoneal tenoxicam was administered to mice in Group 4 after skin closure. All mice were killed after 14 days to determine macroscopic and microscopic IAA; prostaglandin E2 levels were also measured. Postoperative evaluation revealed a reduced IAA formation and a parallel decrease in tissue prostaglandin E2 levels in Group 1 and 2 mice. We conclude that intraperitoneal tenoxicam decreased IAA formation with no peritoneal reaction in the postoperative period.

IMPLICATIONS

Postoperative intraabdominal adhesions can cause intestinal obstruction, pelvic pain, or infertility. In this study, we showed that intraperitoneally administered tenoxicam decreases tissue prostaglandin E2 levels and intraabdominal adhesions in mice.

Expression of recombinant human cyclooxygenase isoenzymes in transfected COS-7 cells in vitro and inhibition by tenoxicam, indomethacin and aspirin

The recent discovery of cyclooxygenase-2 (COX-2), an isoenzyme associated mainly with inflammation created the need to reevaluate cyclooxygenase inhibitors with reliable screening methods. In the present study we standardized a technique to determine the IC50S of cyclooxygenase inhibitors on recombinant human COX-1 and COX-2 expressed in mammalian cells and used it to study the compounds tenoxicam, aspirin and indomethacin. The IC50S of aspirin, indomethacin and tenoxicam for human COX-1 were 0.41 +/- 0.07 microgram/ml, 0.008 +/- 0.003 microgram/ml, and 7.94 +/- 3.28 micrograms/ml, respectively, and for human COX-20.64 +/- 0.16 microgram/ml, 0.09 +/- 0.05 microgram/ml, and 10.61 +/- 1.50 micrograms/ml, for aspirin, indomethacin, and tenoxicam. Tenoxicam had the lowest IC50hCOX-2/IC50hCOX-1 ratio (1.34), followed by aspirin (1.53) and indomethacin (10.82). The system described in the present study provides a simple and efficient way to determine the specificity of NSAID inhibition for each of the human cyclooxygenase isoenzymes separately.