Cyclooxygenases as the principal targets for the actions of NSAIDs

Orally Administered NSAIDs-General Characteristics and Usage in the Treatment of Temporomandibular Joint Osteoarthritis-A Narrative Review

Background: Temporomandibular joint osteoarthritis (TMJ OA) is a degenerative joint disease. The aim of this review was to present the general characteristics of orally administered nonsteroidal anti-inflammatory drugs (NSAIDs) and to present the efficacy of NSAIDs in the treatment of TMJ OA. Methods: PubMed database was analyzed with the keywords: "(temporomandibular joint) AND ((disorders) OR (osteoarthritis) AND (treatment)) AND (nonsteroidal anti-inflammatory drug)". After screening of 180 results, 6 studies have been included in this narrative review. Results and Conclusions: Nonsteroidal anti-inflammatory drugs are one of the most commonly used drugs for alleviation of pain localized in the orofacial area. The majority of articles predominantly examined and described diclofenac sodium in the treatment of pain in the course of TMJ OA. Because of the limited number of randomized studies evaluating the efficacy of NSAIDs in the treatment of TMJ OA, as well as high heterogeneity of published researches, it seems impossible to draw up unequivocal recommendations for the usage of NSAIDs in the treatment of TMJ OA. However, it is highly recommended to use the lowest effective dose of NSAIDs for the shortest possible time. Moreover, in patients with increased risk of gastrointestinal complications, supplementary gastroprotective agents should be prescribed.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): Progress in Small Molecule Drug Development

Ever since the discovery of aspirin, small molecule therapeutics have been widely prescribed to treat inflammation and pain. Aspirin and several small molecule NSAIDs are known to inhibit the enzymes cyclooxygenase-1 (COX-1) and -2 (COX-2). Despite the success of NSAIDs to treat inflammatory disorders, the development of a clinically useful small molecule NSAIDs with decreased side effect profiles is an ongoing effort. The recent discovery and development of selective COX-2 inhibitors was a step toward this direction. Emerging trends are represented by the progress in the development of hybrid agents such as nitric oxide donor-NSAIDs (NO-NSAIDs) and dual COX/lipoxygenase (LOX) inhibitors. This review focuses on the recent advances in the rational design of small molecule NSAIDs in therapy.

Non-steroid anti-inflammatory drugs and digestive diseases

Non-steroid anti-inflammatory drugs (NSAIDs) are a group of medicine used for anti-inflammation, analgesia and antipyretic. Currently NSAIDs are one of the most commonly prescribed medicines world-wide. In this article, we summarized the effect of NSAIDs on digestive diseases, and indroduced the prevention and treatment for mucosal injury of gastrointestenal tract. Meanwhile, we elaborated the pharmaceutical machanism and clinic application of NSAIDs.

Comparison of analgesic and anti-inflammatory efficacy of selective and non-selective cyclooxygenase-2 inhibitors in dental implant surgery

BACKGROUND

The analgesic and anti-inflammatory efficacy of tenoxicam and meloxicam were evaluated in this double-masked, randomized, prospective study by analyzing pain scores and the need for rescue-analgesic agents following dental implant surgery.

METHODS

One hundred patients, in whom 241 dental implants were placed, were divided into two groups. For 4 days beginning the day before surgery, the first group received meloxicam, 15 mg daily, and the second group received tenoxicam, 20 mg daily, followed by 1 hour preoperatively and for 2 days thereafter. Pain intensity was rated by the subjects based on a visual analog scale on the operation day and on the following 6 days. The patients were recommended to use a rescue analgesic if the pain score was > or =4. Postoperative complications, such as edema, hematoma, infection, severe pain, paresthesia, or gastrointestinal complaints, were also noted.

RESULTS

Statistical analysis revealed that 54% of patients in the tenoxicam group and 66% of patients in the meloxicam group used rescue analgesics on day 1. However, the difference between the groups was not significant (chi(2) = 1.05; P = 0.30). The relationship between the reduction of consumption and time was not significant in either group (Z = 0.84; P = 0.40). The relationship between the use of rescue analgesics and the number of implants placed was not significant. Among patients who reported postoperative complications, there was not a statistically significant difference between the groups (chi(2) = 0.04; P = 0.84).

CONCLUSION

Meloxicam and tenoxicam exhibited a similar analgesic and anti-inflammatory efficacy in the present investigation.

[Role of fibroblasts in physiologic, reparative and pathologic processes]

Fibroblast is counted as one of the important cell of the connective tissue. At the present time many phenotypes are known taking part in normal, repair and pathological processes, meanwhile cellular and molecular events occur, where fibroblasts play essential role. Among molecular factors, first of all integrins, growth factors, cytokines and matrix molecules are discussed. The aim of this work is to summarize the morphological, biochemical and functional role of fibroblasts in addition to the physiological process, wound repair and in such pathological processes as Dupuytren's disease, rheumatoid arthritis, Graves' ophthalmopathy and carcinogenesis. It becomes known that fibroblasts participate in dynamic interplay with other cells and with the extracellular matrix. The results of the new investigations clarify better the physiological and pathological processes of the tissue, at the same time give potential help to the therapy of some illnesses. The authors summarise the important data of the subject on the basis of international literature and of their own investigations.

Effects of meloxicam on vascular endothelial growth factor and angiopoietin-2 expression in colon carcinoma cell line HT-29

To investigate the effect of meloxicam, a selected NSAIDs, on cell growth, expression of VEGF and angiopointin-2 (Ang-2) protein in HT-29 cell line, cultured HT-29 cells were treated with meloxicam of various concentrations for various lengths of time. The proliferation of HT-29 was detected by cell counting kit-8 (CCK-8), the cell cycle was determined by flow cytometer and the levels of VEGF and Ang-2 protein in supernatants were examined by enzyme linked immunosorbent assay (ELISA). The mRNA expressions of VEGF and Ang-2 in cultured HT-29 were determined by real-time quantitative reverse-transcription polymerase chain reaction. Our results showed that treatment of meloxicam of different concentrations and for various lengths of time had a cytotoxicic effect on the cell proliferation of HT-29 cells in a concentration-dependant and time-dependant manner. Cell cycle analysis showed that the cells were mainly blocked in G0/G1 phase. The VEGF and Ang-2 protein levels in supernatants of the culture medium were decreased gradually in a concentration-dependent or time-dependent fashion. The mRNA expression of cox-2, VEGF and Ang-2 showed a gradual and concentration-dependent reduction. It is concluded that meloxicam can reduce the expression of VEGF and Ang-2 at the protein and mRNA level in colon carcinoma cell line.

Ibuprofen as a pre-emptive analgesic is as effective as rofecoxib for mandibular third molar surgery

The objective of this study was to compare the pre-emptive analgesic effect of rofecoxib, a cyclooxygenase (COX)-2 inhibitor, with a more traditional and commonly used analgesic, ibuprofen, for mandibular third molar surgery, utilizing a prospective, randomized, double-blind, placebo-controlled clinical trial. Fifty-five healthy patients who were scheduled to undergo surgical removal of an impacted mandibular third molar as outpatients at one of two government dental clinics in Fiji were enrolled. The patients were divided randomly into three groups to receive 50 mg rofecoxib or 400 mg ibuprofen, or a placebo 1 h prior to surgery. A dose of 1000 mg paracetamol was offered as rescue medication. Participants recorded their pain intensity on a 10-cm visual analogue scale 1 h before and just prior to surgery and every 30 min for 6 h following surgery. There were no significant analgesic differences between rofecoxib and ibuprofen at any time intervals postoperatively. Ibuprofen was significantly better at reducing pain at all time intervals by comparison with the placebo. Rofecoxib provided significantly better pain relief compared with the placebo, except at 60, 180, and 240 min postoperatively. Rescue medication use was significantly lower in the rofecoxib and ibuprofen groups by comparison with the placebo group; however, there was no significant difference between the two therapeutic groups. Rescue medication was used by 50%, 25%, and 94% of patients receiving rofecoxib, ibuprofen, and placebo, respectively. Ibuprofen, a commonly used over-the-counter analgesic, is as effective as rofecoxib for the relief of acute postoperative pain following third molar surgery when used pre-emptively.

Combining paracetamol with a selective cyclooxygenase-2 inhibitor for acute pain relief after third molar surgery: a randomized, double-blind, placebo-controlled study

Severe pain after third molar surgery is often encountered and more effective treatment regimes are warranted. The objective of this study was to evaluate if the combination of paracetamol and rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, improves analgesic effects following third molar surgery compared with rofecoxib alone. Paracetamol alone was also evaluated. Altogether 120 patients with moderate to severe pain after third molar surgery were given a single postoperative dose of one of the following treatments: rofecoxib + paracetamol; rofecoxib alone; paracetamol alone; or placebo. Patients assessed level of pain and pain relief every 30 min for 8 h after surgery, and made a global evaluation of the medication 4 and 8 h after surgery. Paracetamol and rofecoxib combined improved the analgesic effect compared with rofecoxib alone for the first 1.5 h. Rofecoxib alone and the combination of paracetamol and rofecoxib had a significantly better analgesic effect than paracetamol alone from 3 h onwards. The early onset of pain relief for the combination of paracetamol and rofecoxib, compared with rofecoxib alone, could be of great importance when treating acute pain after third molar surgery. After data collection for this study, rofecoxib was withdrawn from the market as a result of reported fatal cardiovascular events. Whether this is relevant for short-term use is unknown, but it has to be considered before rofecoxib may be used for pain relief following third molar surgery.

Effects of meloxicam on vascular endothelial growth factor and angiopoietin-2 expression in colon carcinoma cell line HT-29

AIM: To investigate the effect of meloxicam, a nonsteroidal anti-inflammatory drug (NSAID), on the expression of vascular endothelial growth factor (VEGF) and angiopointin-2 (Ang-2) in colon carcinoma cell line HT-29.

METHODS: The cultured HT-29 cells were treated with different concentrations of meloxicam (100, 200, 400, 800 μmol/L) for different time. The proliferation of HT-29 cells was detected by Cell Counting Kit 8 (CCK8). Cell cycle was detected by flow cytometry. The levels of VEGF and Ang-2 protein in the supernatants were determined by enzyme-linked immunosorbent assay (ELISA) and the expression of VEGF and Ang-2 mRNA in HT-29 cells were examined by real-time quantitative reverse-transcription-polymerase chain reaction (RT-PCR).

RESULTS: Meloxicam inhibited the proliferation of HT-29 cells in a concentration- and time-dependent manner (P = 0.000→0.029; 0.000→0.043), and the proliferating activity was decreased with the increase of concentration and prolonging of action time. Meloxicam changed the cycles of HT-29 cells in a concentration-dependent manner, and the number of cells at G₀/G₁ phase was significantly increased (P = 0.000→0.015). The levels of VEGF and Ang-2 protein in supernatants were reduced gradually with the increase of concentration or action time (P = 0.000→0.018; 0.000→0.028). The expression of COX-2, VEGF and Ang-2 mRNA were also reduced with the increase of Meloxicam concentration (P = 0.000→0.025).

CONCLUSION: Meloxicam can reduce the expression of VEGF and Ang-2 at the levels of protein and mRNA in colon carcinoma cell line.

Insights into the role of fibroblasts in human autoimmune diseases

Traditional wisdom has considered fibroblasts as contributing to the structural integrity of tissues rather than playing a dynamic role in physiological or pathological processes. It is only recently that they have been recognized as comprising diverse populations of cells exhibiting complex patterns of biosynthetic activity. They represent determinants that react to stimuli and help define tissue remodelling through the expression of molecules imposing constraints on their cellular neighbourhood. Moreover, fibroblasts can initiate the earliest molecular events leading to inflammatory responses. Thus they must now be viewed as active participants in tissue reactivity. In this short review, I will provide an overview of contemporary thought about the contribution of fibroblasts to the pathogenesis of autoimmune processes through their expression of, and responses to, mediators of inflammation and tissue remodelling.

The time to onset and overall analgesic efficacy of rofecoxib 50 mg: a meta-analysis of 13 randomized clinical trials

OBJECTIVE

To determine the time to onset of analgesia of rofecoxib based on a patient-level meta-analysis of randomized, placebo-controlled, postoperative oral surgery pain studies.

METHODS

A search on MEDLINE and of Merck data on file was conducted to identify studies that met the inclusion criteria. Meta-analysis inclusion criteria required that patients were treated with a single oral dose of rofecoxib 50 mg when they experienced moderate or severe pain after surgical extraction of > or = 2 third molars; study design involved patient randomization, double-blinding, and matching placebo, and onset data from individual patients were available. The meta-analysis of time to onset also required that studies used the two-stopwatch method. Eleven studies fulfilled the onset criteria and included patients who received a single dose of rofecoxib 50 mg (N = 1220) or placebo (N = 483). These studies were analyzed to determine time to onset of analgesia, time to perceptible pain relief, percentage of patients achieving onset of analgesia, and duration of analgesia. Six of the 11 studies included a nonselective nonsteroidal anti-inflammatory drug (N = 303) and were included in the onset meta-analysis for comparison. The meta-analysis of overall efficacy also required that data on total pain relief scores over 8 hours were available. Over-all effectiveness of analgesia was based on analysis of 13 studies involving 1330 rofecoxib patients and 570 placebo patients on the endpoints of total pain relief scores over 8 hours and patient global assessment of response to therapy at 24 hours. Eight of the 13 studies with a nonselective nonsteroidal anti-inflammatory drug comparator (N = 391) were included for the efficacy meta-analysis.

RESULTS

Patient demographics and baseline characteristics were similar across treatment groups in each study. Median time to onset of analgesia for rofecoxib was 34 minutes (95% CI, 31-38 minutes), significantly faster than placebo, which did not achieve onset within the 4 hours the assessment was conducted (P < 0.001). Duration of analgesia for rofecoxib 50 mg was > 24 hours. Rofecoxib achieved a greater mean total pain relief score over 8 hours than placebo (17.4 versus 4.4; P < 0.001) and a greater patient response rate on patient global assessment of response to therapy at 24 hours than placebo (73% versus 16%; P < 0.001). Outcomes were similar between the rofecoxib group and the nonselective nonsteroidal anti-inflammatory drug group.

CONCLUSION

In this meta-analysis of over 1200 rofecoxib-treated patients, a single dose of rofecoxib 50 mg demonstrated a rapid onset of analgesia in approximately half an hour combined with sustained effectiveness, supporting its use as a treatment of acute pain.

Double-blind study to evaluate efficacy and safety of meloxicam 7.5 mg and 15 mg versus mefenamic acid 1500 mg in the treatment of primary dysmenorrhea

OBJECTIVE

Assessment of efficacy and safety of meloxicam 7.5 mg and 15 mg once a day (o.a.d.) compared with mefenamic acid 500 mg three times a day (t.i.d.), over a treatment period of 3-5 days, during three menstrual cycles, for primary dysmenorrhea.

STUDY DESIGN

Multicenter, multinational, double-blind, double-dummy, three parallel groups, randomized trial, phase IIb, 337 patients. Treatment group comparisons of continuous variables were carried out using the Kruskal-Wallis test and Wilcoxon signed rank tests. Efficacy was analyzed using Fisher and chi(2)-tests.

RESULTS

Meloxicam 7.5 mg and 15 mg showed a similar profile in pain reduction and dysmenorrhea symptoms when compared with mefenamic acid. Thirty-five subjects presented with gastrointestinal (GI) adverse events (AEs). Two-thirds of those 35 subjects were in the mefenamic acid group. There were no differences between the safety profiles of the two meloxicam dosages. Laboratory abnormalities did not differ in incidence among the treatment groups.

CONCLUSION

Both of the daily doses of meloxicam tested were comparable to 500 mg mefenamic acid t.i.d. in relieving dysmenorrhea symptoms, and meloxicam seems to have a better gastrointestinal tolerability profile.

A Randomized, Double-Blind, Parallel-Group Study Comparing the Analgesic Effect of Etoricoxib to Placebo, Naproxen Sodium, and Acetaminophen With Codeine Using the Dental Impaction Pain Model

OBJECTIVE

To compare the overall analgesic effect, including time to onset, peak and duration of effect for etoricoxib 120 mg, a new COX-2 selective inhibitor, in patients with acute pain to that of placebo. Naproxen sodium 550 mg and acetaminophen/codeine 600/60 mg were the active comparators.

METHODS

A total of 201 patients with moderate to severe pain following surgical extraction of > or = 2 third molars, of which at least the mandibular tooth was impacted, were randomly allocated to receive single oral doses of placebo (n = 50), etoricoxib 120 mg (n = 50), naproxen sodium 550 mg (n = 51), or acetaminophen/codeine 600/60 mg (n = 50). The endpoints included total pain relief over 8 hours (TOPAR8, primary end point), sum of pain intensity difference over 8 hours, patient's global evaluation, onset, peak, and duration of analgesia.

RESULTS

Etoricoxib 120 mg had a significantly greater least squares (LS) mean TOPAR8 score than placebo (20.9 vs 5.4; P < 0.001) and acetaminophen/codeine 600/60 mg (20.9 vs 11.5; P < 0.001), and a similar LS mean TOPAR8 score to naproxen sodium 550 mg (20.9 vs 21.3). All three active treatments had rapid onset of analgesia, median time approximately 30 minutes. The duration of analgesic effect, defined as median time to rescue medication use, was >24 hours for etoricoxib, 20.8 hours for naproxen sodium, 3.6 hours for acetaminophen/codeine, and 1.6 hours for placebo.

DISCUSSION

Etoricoxib is a new COX-2 selective inhibitor under development for treatment of osteoarthritis, rheumatoid arthritis, and acute pain. In this study, etoricoxib 120 mg provided rapid and long-lasting pain relief to patients with moderate-to-severe postdental surgery pain. Etoricoxib was generally well tolerated.

Selective cyclooxygenase-2 inhibition: a target in cancer prevention and treatment

A major goal in the area of cancer prevention and treatment is to make rational use of defined molecular targets in order to block carcinogenesis. Studies conducted in experimental animal models for many human cancers, including those of lung, skin, mammary gland, urinary bladder, colon, and pancreas, have demonstrated that carcinogenesis often may be inhibited by the administration of a highly diverse group of biologic and chemical agents. One very promising and well-studied target is cyclooxygenase (COX)-2. Interestingly, a number of cancers appear to overexpress the COX-2 enzyme, which may play several roles in carcinogenesis. Recent clinical studies have demonstrated the effect of COX-2 inhibitors in the treatment of familial adenomatous polyposis, a genetic disorder that increases the risk for developing colorectal cancer. Ongoing clinical trials with COX-2 inhibitors will increase our understanding and may give us profound insights into the general applicability of this new targeted approach for cancer control.

Up-regulation of prostaglandin E2 synthesis by interleukin-1beta in human orbital fibroblasts involves coordinate induction of prostaglandin-endoperoxide H synthase-2 and glutathione-dependent prostaglandin E2 synthase expression

Prostaglandin E(2) (PGE(2)) production involves the activity of a multistep biosynthetic pathway. The terminal components of this cascade, two PGE(2) synthases (PGES), have very recently been identified as glutathione-dependent proteins. cPGES is cytoplasmic, apparently identical to the hsp90 chaperone, p23, and associates functionally with prostaglandin-endoperoxide H synthase-1 (PGHS-1), the constitutive cyclooxygenase. A second synthase, designated mPGES, is microsomal and can be regulated. Here we demonstrate that mPGES and PGHS-2 are expressed at very low levels in untreated human orbital fibroblasts. Interleukin (IL)-1beta treatment elicits high levels of PGHS-2 and mPGES expression. The induction of both enzymes occurs at the pretranslational level, is the consequence of enhanced gene promoter activities, and can be blocked by dexamethasone (10 nm). SC58125, a PGHS-2-selective inhibitor, could attenuate the induction of mPGES, suggesting a dependence of this enzyme on PGHS-2 activity. IL-1beta treatment activates p38 and ERK mitogen-activated protein kinases. Induction of both mPGES and PGHS-2 was susceptible to either chemical inhibition or molecular interruption of these pathways with dominant negative constructs. These results indicate that the induction of PGHS-2 and mPGES by IL-1beta underlies robust PGE(2) production in orbital fibroblasts.

Evaluation of preoperative administration of the cyclooxygenase-2 inhibitor rofecoxib for the treatment of postoperative pain after lumbar disc surgery

OBJECTIVE

A combination of analgesics with different mechanisms of action may improve postoperative pain control and reduce the incidence of side effects. This study was designed to assess the efficacy of preoperative administration of rofecoxib (Vioxx; Merck & Co., Inc., Somerset, NJ) in reducing pain and opioid requirements after single-level lumbar microdiscectomy.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was performed on 61 consenting patients who were considered American Society of Anesthesiologists Class I or II and who were scheduled for elective single-level lumbar microdiscectomy. Patients received either two doses of rofecoxib 50 mg or a placebo preoperatively. The outcome measures included morphine use in the postanesthesia care unit (PACU), discharge times, and side effect profile. Data were analyzed by use of independent sample t tests for continuous variables or chi(2) tests for categorical variables. A P value of <0.05 was considered significant.

RESULTS

The two groups were comparable with respect to patient characteristics, intraoperative opioid and hypnotic consumption, and duration of surgery. Patients in the rofecoxib group required significantly less morphine postoperatively. Significantly more patients in the placebo group reported pain scores greater than 7 at admission to the PACU. Time to first request for analgesia was shorter in the placebo group, but the difference did not reach statistical significance. There were no significant differences between groups in the incidence of nausea, time to discharge from the PACU, or hospital stay.

CONCLUSION

Preoperative rofecoxib is effective in reducing postoperative narcotic consumption in patients undergoing lumbar laminectomy. The use of rofecoxib does not shorten PACU length of stay or hospital discharge time. These outcome measures depend on multiple administrative factors.

The role of eicosanoids, cyclooxygenases, and nonsteroidal anti-inflammatory drugs in colorectal tumorigenesis and chemoprevention

There is mounting evidence from studies on experimental cancer in rodents, interventional studies in patients with familial adenomatous polyposis, and some, but not all, epidemiologic investigations, that suggests a chemopreventive effect of aspirin and nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) against colorectal cancer. In addition, the mechanisms by which these agents modulate tumorigenesis are being elucidated in laboratory experiments. Currently available NSAIDs are unlikely to have an acceptable benefit-to-risk ratio for long-term use in an asymptomatic population. Once the discrete chemopreventive mechanisms are established and the genetic background and risk factor profile of individuals who will benefit from chemoprevention are clarified, a low-dose combination of NSAIDs with different targets may optimize efficacy and minimize toxicity. At present, however, colectomy is still the treatment of choice for patients with familial adenomatous polyposis, and early screening and regular surveillance colonoscopies are the choices for those at risk for hereditary nonpolyposis colorectal cancer. In the average-risk individual, endoscopic screening and surveillance will remain the core of efforts to prevent sporadic colorectal cancer.

Selective COX-2 inhibitors: a review of their therapeutic potential and safety in dentistry

Anti-inflammatory analgesics are commonly used medications in dental and medical practice. Their uses in dentistry include use as analgesics and as anti-inflammatory agents. In addition, antipyretic action accompanies the medication. The action of these groups of drugs depends on the dose provided. Analgesic and antipyretic effects occur at low dose, whereas analgesic effects occur at high dose. Among the common side effects of this class of medications are gastrointestinal irritation with potential for ulceration, increased tendency for bleeding due to antiplatelet effects, and long-term chronic dosing effects on renal function may occur. Recent developments in the anti-inflammatory group of medications include the introduction of cyclooxygenase-II inhibitors. These agents offer potentially significant advantages because of their relative lack of gastrointestinal irritation. Because of this, it is likely that these medications will be frequently used in the management of dental and medical conditions. Patients will present while on these medications, and these agents may serve as medications for management of dental pain, postsurgical pain, and for anti-inflammatory effects. The current literature indicates that COX-2 inhibitors offer substantial benefits because of their favorable gastrointestinal profiles and because of their lack of effect on platelet function.

The optimal analgesic dose of rofecoxib: Overview of six randomized controlled trials

BACKGROUND

Rofecoxib, which specifically inhibits cyclooxygenase-2, is indicated for relief of the signs and symptoms of osteoarthritis and for the management of acute pain in adults. The authors present an overview of six placebo-controlled trials designed to evaluate the single-dose analgesic efficacy of a range of doses of rofecoxib in the treatment of postoperative dental pain.

METHODS

The six studies included doses of rofecoxib ranging from 7.5 to 500 milligrams. Maximal analgesic doses of a nonsteroidal anti-inflammatory drug, or NSAID, either naproxen sodium (550 mg) or ibuprofen (400 mg), were used as active comparators in each study. Analgesic efficacy was assessed with the use of validated self-administered questionnaires. The primary endpoint in each study was the total pain relief over the eight-hour postdose period. Additional endpoints were used to characterize the onset of analgesia and peak analgesic effect.

RESULTS

The results of these studies demonstrated that the efficacy of rofecoxib was dose-related, with 50 mg being consistently more effective than placebo for all measures of analgesic efficacy. Moreover, 50 mg was the lowest dose that reproducibly demonstrated an analgesic effect comparable to the effect of maximum single analgesic doses of NSAIDs.

CONCLUSION

The results of these studies support the recommended dose of 50 mg of rofecoxib once daily for the management of pain.

CLINICAL IMPLICATIONS

Rofecoxib, at a dose of 50 mg, is effective in the management of postoperative dental pain.

Hyaluronic acid supplementation

As evidenced by publication of a new set of guidelines for the treatment of osteoarthritis (OA) by the American College of Rheumatology after only 5 years, modalities available for the management of OA have undergone significant changes. New therapeutic approaches include the use of cyclo-oxygenase-2 inhibitors, and intra-articular hyaluronans (HA). HA, found in a number of body tissues, is altered in the presence of osteoarthritis with decreased molecular weight and concentration resulting in impaired viscoelasticity. Hyaluronan preparations have been shown to decrease pain and increase function in patients with osteoarthritis of the knee. Mechanisms of therapeutic effect include restoration of more normal synovial fluid with improved viscoelasticity, effects on cartilage biosynthesis and degradation, anti-inflammatory effects, and direct analgesic effects. Studies in animal models, and preliminary studies in humans suggest that hyaluronans may have a structure-modifying effect in OA. Hyaluronans represent a substantive addition to the therapeutic armamentarium in osteoarthritis.

The pharmacological basis of contemporary pain management

Pain management has become an increasingly well researched area in medicine over recent years, and there have been advances in a number of areas. While opioids remain an integral part of pain-management strategies, there is now an emphasis on the use of adjuvant drugs, such as paracetamol and anti-inflammatory agents, which through physiological or pharmacological synergism, both enhance pain control and reduce opioid use. The management of neuropathic pain continues to be a challenge. Anti-epileptics and antidepressants, together with clonidine and ketamine, provide the foundations for treatment. Another area of interest has been the widespread use of patient-controlled analgesia and the administration of some drugs, especially opioids, by means other than traditional oral and parenteral routes. The number of new drugs that have reached the stage of clinical trials has been small, yet they offer exciting possibilities. The epibatidine analogue ABT-594 and zinconitide both offer novel approaches to the management of neuropathic pain states, while selective cyclo-oxygenase-2 inhibitors and nitroaspirins may see advances in the management of nociceptive pain states.

Leukoregulin upregulation of prostaglandin endoperoxide H synthase-2 expression in human orbital fibroblasts

Human orbital fibroblasts from patients with severe thyroid-associated ophthalmopathy are particularly susceptible to the actions of a variety of proinflammatory molecules. In this study, we demonstrate that the inductions of prostaglandin endoperoxide H synthase-2 (PGHS-2), interleukin (IL)-1alpha, and IL-1beta by leukoregulin, a product of activated T lymphocytes, are far more robust in orbital fibroblasts than those observed in dermal fibroblasts. These actions of leukoregulin are mediated through an intermediate induction of IL-1alpha. In contrast, leukoregulin also induces IL-1-receptor antagonist (IL-1ra) expression in orbital fibroblasts, but this induction is considerably greater in dermal fibroblasts (2.3- vs. 8.5-fold). Interrupting the effects of IL-1alpha, either with a neutralizing antibody or with exogenous IL-1ra, can block the induction of PGHS-2 by leukoregulin. Leukoregulin increases PGHS-2 gene transcription in orbital fibroblasts but exerts the major effect on cyclooxygenase expression by enhancing the stability of mature PGHS-2 mRNA. The cytokine triggers nuclear translocation of nuclear factor-kappaB (NF-kappaB) p50/p50 homodimers and p50/p65 heterodimers, and an inhibitor of this transcriptional factor, pyrrolidinedithiocarbamate, can attenuate the PGHS-2 induction. Thus differential inducibility of the members of the IL-1 family of genes in orbital fibroblasts would appear to underlie, at least in part, the differences in PGHS-2 induction observed in orbital and dermal fibroblasts. NF-kappaB plays an important role in mediating the effects of leukoregulin on PGHS-2 expression.

Comparison of rofecoxib and celecoxib, two cyclooxygenase-2 inhibitors, in postoperative dental pain: a randomized, placebo- and active-comparator-controlled clinical trial

Pain is a common complaint, often occurring in conjunction with inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used analgesic agents in ambulatory patients. In recent studies, the cyclooxygenase-2 (COX-2) inhibitor rofecoxib demonstrated analgesic effects similar to those of NSAIDs in the treatment of acute pain and primary dysmenorrhea. The present randomized, single-dose, double-blind, double-dummy, placebo- and active-comparator-controlled, parallel-group study was undertaken to compare the analgesic efficacy of the COX-2 inhibitors rofecoxib 50 mg and celecoxib 200 mg with that of ibuprofen 400 mg and placebo in patients with postoperative dental pain. Two hundred and seventy-two patients experiencing pain after the removal of > or =2 third molars were randomized according to pain severity (moderate vs severe) to receive a single dose of placebo (n = 45), rofecoxib 50 mg (n = 90), celecoxib 200 mg (n = 91), or ibuprofen 400 mg (n = 46). Using a patient diary, patients recorded pain intensity, pain relief, and global evaluations throughout the 24-hour period after dosing. The overall analgesic effect, onset of action, peak effect, and duration of effect were evaluated, with the primary end point being total pain relief over 8 hours (TOPAR8). The safety profile was assessed on the basis of physical findings, laboratory results, and spontaneous reports of adverse experiences. The results showed that compared with celecoxib, rofecoxib had superior analgesic effects on all measures of analgesic efficacy, including overall analgesic effect (TOPAR8, 18.3 vs. 12.5; P<0.001), time to onset of effect (30 vs. 60 minutes; P = 0.003), peak pain relief (score, 2.8 vs 2.3; P<0.05), and duration of effect (>24 vs. 5.1 hours; P<0.001). In addition, rofecoxib's analgesic efficacy was similar to that of ibuprofen (TOPAR8, 18.3 vs. 17.0; P = 0.460), but the duration was longer (P<0.05); with ibuprofen, the time to on set was 24 minutes, peak pain relief score was 2.9, and duration of analgesic effect was 8.9 hours. The safety profile was similar across all treatment groups. Thus rofecoxib provided analgesic efficacy superior to that of celecoxib and comparable to that of ibuprofen in the treatment of patients with acute postoperative dental pain.

HMC-1 mast cells activate human orbital fibroblasts in coculture: evidence for up-regulation of prostaglandin E2 and hyaluronan synthesis

The purpose of this study was to determine the effects of mast cell coculture on human orbital fibroblasts. Thyroid-associated ophthalmopathy is characterized by infiltration of lymphocytes and mast cells and connective tissue activation in the orbit, leading to a disordered accumulation of hyaluronan and intense inflammation. Here, we report that HMC-1, an established human mast cell line, can activate human orbital fibroblasts to produce increased levels of prostaglandin E2 (PGE2) and hyaluronan when cocultured. HMC-1 cells up-regulate, in these fibroblasts, the expression of PG endoperoxide H synthase-2 (EC 1.14.99.1, PGHS-2), the inflammatory cyclooxygenase. This induction, at a pretranslational level, underlies the increase in PGE2 synthesis. The up-regulation can be attenuated with dexamethasone (10 nM), and the increase in PGE2 production can be inhibited by SC 58125, a specific PGHS-2 inhibitor. Moreover, anti-interleukin-4 receptor antibodies can block prostanoid production in the fibroblasts elicited by HMC-1 cells, suggesting that this cytokine might represent a molecular conduit for mast cell/fibroblast cross-talk. HMC-1 cells also increased hyaluronan synthesis, as was evidenced by a 2-fold increase in [3H]glucosamine incorporation into the macromolecule. To our knowledge, these findings are the first demonstrating the ability of mast cells to activate orbital fibroblasts, and the findings suggest a potential role for these cell-cell interactions in the pathogenesis of thyroid-associated ophthalmopathy.

Prostaglandin-endoperoxide H synthase-2 expression in human thyroid epithelium. Evidence for constitutive expression in vivo and in cultured KAT-50 cells

Prostaglandin-endoperoxide H synthase (PGHS) (EC 1.14.99.1) expression was examined in human thyroid tissue and in KAT-50, a well differentiated human thyroid epithelial cell line. PGHS-1 is found constitutively expressed in most healthy tissues, whereas PGHS-2 is highly inducible and currently thought to be expressed, with few exceptions, only in diseased tissues. Surprisingly, PGHS-2 mRNA and protein were easily detected in normal thyroid tissue. KAT-50 cells express high levels of constitutive PGHS-2 mRNA and protein under basal culture conditions. Compounds usually associated with PGHS-2 induction, including interleukin-1beta (IL-1beta), phorbol 12-myristate 13-acetate, and serum transiently down-regulated PGHS-2 expression. Human PGHS-2 promoter constructs (-1840/+123 and -831/+123) fused to a luciferase reporter and transfected into untreated KAT-50 cells exhibited substantial activity. NS-398, a highly selective inhibitor of PGHS-2 could inhibit substantial basal prostaglandin E2 production. Exogenous IL-1 receptor antagonist or IL-1alpha neutralizing antibodies could attenuate constitutive PGHS-2 expression in KAT-50 cells, suggesting that endogenous IL-1alpha synthesis was driving PGHS-2 expression. Our findings suggest that normal thyroid epithelium expresses high constitutive levels of PGHS-2 in situ and in vitro and this enzyme is active in the generation of prostaglandin E2. Thus, unprovoked PGHS-2 expression might be considerably more widespread in healthy tissues than is currently believed.