(1/338) Dose-loading with hydroxychloroquine improves the rate of response in early, active rheumatoid arthritis: a randomized, double-blind six-week trial with eighteen-week extension.
OBJECTIVE: To investigate the usefulness of hydroxychloroquine (HCQ) dose-loading to increase the percentage of responders or rate of response in treating rheumatoid arthritis (RA). METHODS: Two hundred twelve patients with early RA (mean duration 1.5 years) were enrolled in a 24-week trial. Patients were stabilized with 1,000 mg naproxen/day and then began a 6-week, double-blind trial comparing treatment with HCQ at 400 mg/day (n = 71), 800 mg/day (n = 71), and 1,200 mg/day (n = 66), followed by 18 weeks of open-label HCQ treatment at 400 mg/day. RESULTS: All patients had mild, active disease at the time of initiation of HCQ treatment (31-43% rheumatoid factor positive; no previous disease-modifying antirheumatic drugs; mean swollen joint count 8.6-10.4). Based on the Paulus criteria, response during the 6-week double-blind portion of the study was 47.97%, 57.7%, and 63.6% in the 400 mg/day, 800 mg/day, and 1,200 mg/day groups, respectively (P = 0.052). Discontinuations for adverse events were dose related (3 in the 400 mg/day group, 5 in the 800 mg/day group, 6 in the 1,200 mg/day group). Most involved the gastrointestinal (GI) system, with the background naproxen treatment possibly contributing. Ocular abnormalities occurred in 17 of 212 patients (8%) but were not dose related. CONCLUSION: Dose-loading with HCQ increased the degree of response at 6 weeks in this group of patients with early, predominantly seronegative RA. Adverse GI events were dose related, while adverse ocular events were not. (+info)
(2/338) Nitric oxide-releasing NSAIDs inhibit interleukin-1beta converting enzyme-like cysteine proteases and protect endothelial cells from apoptosis induced by TNFalpha.
BACKGROUND: Nitric oxide (NO)-releasing NSAIDs are a new class of NSAID derivatives with markedly reduced gastrointestinal toxicity. Although it has been demonstrated that NO-NSAIDs spare gastric mucosal blood flow, molecular determinants involved in this effect are unknown. AIM: To investigate the effect of aspirin, naproxen and flurbiprofen, and their NO-derivatives, on gastric apoptosis and endothelial cell damage induced by tumour necrosis factor-alpha (TNFalpha). In other systems, TNFalpha-induced apoptosis is mediated by caspases, a growing family of cysteine proteases similar to the IL-1beta converting enzyme (ICE), and so we have investigated whether NO-NSAIDs modulate ICE-like endopeptidases. METHODS: Rats were treated orally with aspirin, naproxen and flurbiprofen, or their NO-releasing derivatives in equimolar doses, and were killed 3 h later to assess mucosal damage and caspase activity. Endothelial cells (HUVECs) were obtained from human umbilical cord by enzymatic digestion. Caspase 1 and 3 activities were measured by a fluorimetric assay using selective peptides as substrates and inhibitors. Apoptosis was quantified by ELISA specific for histone-associated DNA fragments and by the terminal transferase nick-end translation method (TUNEL). RESULTS: In vivo NSAID administration caused a time-dependent increase in gastric mucosal damage and caspase activity. NCX-4016, NO-naproxen and NO-flurbiprofen did not cause any mucosal damage and prevented cysteine protease activation. NSAIDs and NO-NSAIDs stimulated TNFalpha release. Exposure to TNFalpha resulted in a time- and concentration-dependent HUVEC apoptosis, an effect that was prevented by pretreating the cells with NCX-4016, NO-naproxen, NO-flurbiprofen, SNP or Z-VAD.FMK, a pan-caspase inhibitor. The activation of ICE-like cysteine proteases was required to mediate TNFalpha-induced apoptosis of HUVECs. Exogenous NO donors inhibited TNFalpha-induced cysteine protease activation. Inhibition of caspase activity was due to S-nitrosylation of ICE/CPP32-like proteases. NO-NSAIDs prevented IL-1beta release from endotoxin-stimulated macrophages. CONCLUSIONS: NO-releasing NSAIDs are a new class of non-peptide caspase inhibitors. Inhibition of ICE-like cysteine proteases prevents endothelial cell damage induced by pro-inflammatory agents and might contribute to the gastro-protective effects of NO-NSAIDs. (+info)
(3/338) Kinetic basis for selective inhibition of cyclo-oxygenases.
Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit the formation of prostaglandins by cyclo-oxygenases (COX). The discovery of a second COX isoform (COX-2) associated with inflammation led to agents that selectively inhibit COX-2, e.g. celecoxib. We evaluated the kinetics of inhibition of celecoxib and several NSAIDs. Celecoxib displays classic competitive kinetics on COX-1 (Ki=10-16 microM). An initial competitive interaction with COX-2 can also be discerned with celecoxib (Ki=11-15 microM), followed by a time-dependent interaction leading to potent inhibition, characterized as inactivation (Kinact=0.03-0.5 s-1). Half-maximal inhibition (IC50) using end-point assays reflects the competitive component on COX-1 (IC50=4-19 microM) and the inactivation component on COX-2 (IC50=0.003-0.006 microM). NSAIDs exhibit four distinct modes of COX inhibition based on kinetic behaviour: (1) competitive, e.g. ibuprofen; (2) weak binding, time-dependent, e.g. naproxen, oxicams; (3) tight binding, time-dependent, e.g. indomethacin; (4) covalent, e.g. aspirin. In addition, most NSAIDs display different kinetic behaviour for each isoform. Weakly binding inhibitors show variable behaviour in enzyme assays, with apparent inhibitory activity being markedly influenced by experimental conditions; determination of kinetic constants with this class is unreliable and IC50 values are strongly dependent on assay conditions. Although IC50 determinations are useful for structure/activity analyses, the complex and distinct mechanisms of enzyme inhibition of each COX isoform by the NSAIDs renders comparison of inhibitory activity on COX-1 and COX-2 using IC50 ratios of questionable validity. (+info)
(4/338) Renal changes associated with naproxen sodium administration in cynomolgus monkeys.
Naproxen sodium was administered to cynomolgus monkeys (Macaca fascicularis) by oral gavage at daily doses of 44, 88, or 176 mg/kg for 2 wk (2 monkeys/gender) or of 44 mg/kg for 13 wk (4 monkeys/gender). Body weight loss occurred in at least one monkey in all naproxen sodium-dosed groups in the 2-wk (up to 16% loss) and 13-wk (up to 22% loss) studies. Increases in plasma naproxen concentrations were dose proportional between 44 and 88 mg/kg but were less than dose proportional between 88 and 176 mg/kg. Up to 2-fold increases in creatinine and/or serum urea nitrogen values as well as higher renal weights occurred in monkeys receiving 176 mg/kg for 2 wk or 44 mg/kg for 13 wk. Microscopically, renal changes were observed in all naproxen sodium-dosed groups. Renal findings after 2 wk of exposure included increased interstitial ground substance, tubular dilatation, and tubulointerstitial nephritis; in the 13-wk study, cortical tubular atrophy and interstitial fibrosis were also observed. These studies identify the kidney as the target organ of naproxen sodium in cynomolgus monkeys. (+info)
(5/338) Effects of nabumetone compared with naproxen on platelet aggregation in patients with rheumatoid arthritis.
OBJECTIVE: To test the hypothesis that nabumetone (a partially selective cyclooxygenase-(COX)-2 inhibitor) has less effect on platelet aggregation than naproxen (a non-selective COX-inhibitor) in patients with rheumatoid arthritis (RA). METHODS: A crossover study in 10 RA patients was performed, using either nabumetone or naproxen for two weeks, and, after a washout period of two weeks, the other drug during another two weeks. Platelet aggregation studies were performed and bleeding time was assessed before and after each treatment period. RESULTS: Maximum platelet aggregation induced by epinephrine and by collagen was significantly more reduced after the use of naproxen than of nabumetone; secondary aggregation induced by ADP and epinephrine disappeared more often by naproxen than by nabumetone. Bleeding times were not influenced. CONCLUSION: COX dependent platelet aggregation in RA patients seems to be more inhibited by naproxen than by nabumetone. This may be relevant for patients requiring non-steroidal anti-inflammatory drug treatment but who have an increased risk of bleeding as well. (+info)
(6/338) Gastrointestinal toxicity of non-steroidal anti-inflammatory drugs: the effect of nimesulide compared with naproxen on the human gastrointestinal tract.
This overview includes theories and evaluation of non-steroidal anti-inflammatory drug (NSAID)-induced gastrointestinal toxicity. Factors in damage include microvascular aspects, neutrophil recruitment, mucosal prostaglandins, gastrointestinal secretions and bacteria. We have proposed an extensive simplified framework that includes an important local initiating effect which may involve NSAID accumulation, interaction with surface phospholipids, events that alter cellular ATP, and local/systemic effects of cyclooxygenase (COX) inhibition. COX-2-selective drugs are desirable not only because they spare COX-1 and so avoid gastrointestinal toxicity, but also because COX-2-selective agents are only weakly acidic and therefore avoid substantial accumulation in the gastric mucosa. Short-term endoscopy studies of NSAIDs are important initially to evaluate human gastroduodenal tolerability. They show that injury increases with the amount of NSAIDs even though the lowest therapeutic doses inhibit gastric COX almost completely, and that the more-acidic NSAIDs tend to cause greater gastric damage. Long-term endoscopy studies involve NSAID ingestion for at least 3 months. A main question is the extent to which the ulcers seen cause symptoms, substantial bleeding and/or perforation. Measurement of serious outcomes is thought by many to be the best assessment of gastrointestinal safety, but studies find marked variations even with the same drug. Damage to the small intestine by NSAIDs is even more frequent than to the upper gastrointestinal tract, but is difficult to evaluate. Conventional acidic NSAIDs increase the permeability of human small intestine, probably by a non-prostaglandin mechanism, but nimesulide does not do so, possibly because of its very weak acidity. (+info)
(7/338) Tramadol allows reduction of naproxen dose among patients with naproxen-responsive osteoarthritis pain: a randomized, double-blind, placebo-controlled study.
OBJECTIVE: To demonstrate that in patients receiving naproxen for the pain of osteoarthritis (OA), the addition of tramadol will allow a reduction in the naproxen dosage without compromising pain relief. METHODS: This trial consisted of a 5-week open-label run-in and an 8-week double-blind phase. Patients with at least moderate pain (> or =40 mm on a 100-mm visual analog scale) of OA of the knee after a 1-week medication washout were treated with naproxen 500 mg/day for 1 week. Patients whose pain scores were reduced to <20 mm were discontinued. The remaining patients received naproxen 1,000 mg/day for 3 weeks. Tramadol 200 mg/day was added during the third week. Patients were then randomized in a double-blind manner to continue tramadol 200 mg/day or to begin placebo in addition to naproxen. Randomization was stratified based on response to naproxen 1,000 mg/day. During the double-blind phase, the naproxen dose was reduced by 250 mg every 2 weeks. The primary efficacy end point was the minimum effective naproxen dose (MEND). The MEND was defined as 250 mg above the naproxen daily dosage at which pain relief was no longer adequate. Patients discontinuing the double-blind phase of the study for reasons other than lack of efficacy were assigned a MEND equal to the last naproxen dose received. If the effect of treatment between the responder and nonresponder groups was statistically different, the difference in the MEND was assessed separately within the groups. RESULTS: Of 236 patients randomized (mean age 61 years; 147 females), 90 were stratified as naproxen responders and 146 as naproxen nonresponders. There was a significant difference (P = 0.040) in the treatment effect between the naproxen responders and nonresponders, thus demonstrating a difference in the way responders and nonresponders react to a decrease in naproxen dosage after the addition of tramadol. Among naproxen responders, the MEND was significantly lower in patients receiving tramadol (n = 36) than in patients receiving placebo (n = 54), 221 mg versus 407 mg, respectively (P = 0.021). For the naproxen nonresponders, the mean MEND was 419 mg in the tramadol group and 396 mg in the placebo group (P = 0.706). CONCLUSION: In patients with painful OA of the knee responding to naproxen 1,000 mg/day, the addition of tramadol 200 mg/day allows a significant reduction in the dosage of naproxen without compromising pain relief. (+info)
(8/338) Change in pain threshold by meperidine, naproxen sodium, and acetaminophen as determined by electric pulp testing.
The purpose of this study was to compare changes in pain threshold caused by meperidine, naproxen sodium, acetaminophen, and placebo. The change in pain threshold was measured by electric pulp testing. Acetaminophen elevated the pain threshold statistically significantly. Clinically, however, the superiority of acetaminophen is questionable. No elevation of the pain threshold occurred with narcotic drugs or with nonsteroidal anti-inflammatory drugs: our research shows that the electric pulp tests of patients who have taken these drugs preoperatively will have results similar to those of patients who have taken no drugs. We question the philosophy of administering these drugs for change in pain threshold at the levels used here preoperatively. (+info)