naproxen-n-butyl-nitrate and Stomach-Ulcer

The objective of this endoscopic study was to compare the effects on the gastroduodenal mucosa of healthy volunteers of different doses and dosing regimens of AZD3582, a cyclooxygenase-inhibiting nitric oxide donator (CINOD), with equimolar doses of naproxen.. Healthy volunteers were enrolled in a single-centre, randomized, double-blind, crossover trial consisting of two 12-day treatment periods and employing six sequences. The groups were: AZD3582 750 mg daily versus 375 mg twice daily (n=25), AZD3582 375 mg twice daily versus 750 mg twice daily (n=25) and naproxen 250 mg twice daily versus 500 mg twice daily (n=25).. Gastroduodenal tract damage was similar with AZD3582 375 mg twice daily and 750 mg twice daily (mean number of erosions and ulcers+/-SD: 2.88+/-3.95 versus 3.08+/-2.80, respectively; p=0.824; 1 ulcer counted as 10 erosions). There was an indication of decreased gastroduodenal toxicity with AZD3582 750 mg daily compared with 375 mg twice daily (0.92+/-2.08 versus 2.71+/-4.75, respectively; p=0.068). Gastroduodenal toxicity was significantly lower with AZD3582 375 mg twice daily than with naproxen 250 mg twice daily (2.88+/-3.95 versus 6.16+/-9.36; p<0.05), and with AZD3582 750 mg twice daily versus naproxen 500 mg twice daily (3.08+/-2.80 versus 6.68+/-6.97; p<0.05). Equimolar twice-daily doses of AZD3582 and naproxen resulted in similar naproxen plasma levels and serum thromboxane B(2) inhibition.. AZD3582 has an improved gastroduodenal safety profile compared with equimolar doses of naproxen. The gastroduodenal effects of AZD3582 375 mg and AZD3582 750 mg twice daily are similar. A once-daily regimen of AZD3582 might be less gastrotoxic than a twice-daily regimen.

Topics: Adult; Cross-Over Studies; Cyclooxygenase Inhibitors; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Duodenal Ulcer; Endoscopy, Gastrointestinal; Female; Humans; Intestinal Mucosa; Male; Naphthalenes; Naproxen; Reference Values; Stomach Ulcer; Thromboxane B2; Treatment Outcome

Administration of selective and nonselective cyclooxygenase (COX)-2 inhibitors to rheumatoid arthritis patients taking low doses of acetylsalicylic acid (ASA) for cardiovascular prevention associates with increased risk of gastrointestinal bleeding. The present study was undertaken to investigate whether administration of HCT-3012 [(S)-6-methoxy-alpha-methyl-2-naphthaleneacetic acid 4-(nitrooxy)butyl ester], a nitric oxide (NO)-releasing derivative of naproxen, exacerbates gastric mucosal injury in arthritic rats administered low doses of ASA. Our results demonstrated that while treating arthritic rats with a dose of 30 mg/kg/day ASA causes detectable mucosal injury, but had no effect on arthritis score and interleukin-6 plasma levels, coadministration of naproxen (10 mg/kg/day) and celecoxib (30 mg/kg/day), in combination with ASA from day 7 to day 21, attenuates arthritis development (P <0.01 versus arthritis alone), but markedly enhanced gastric mucosal damage caused by ASA (P <0.01 versus ASA alone). In contrast, coadministration of HCT-3012 (15 mg/kg/day) significantly attenuated arthritis development, because HCT-3012 was equally or more effective than naproxen and celecoxib in attenuating local and systemic inflammation (P >0.001 versus arthritis) without exacerbating gastric mucosal injury caused by ASA. Arthritis development associates with gastric COX-2 induction, mRNA and protein, and enhanced gastric prostaglandin E2 (PGE2) synthesis (P <0.01 versus control rats). Although all treatments, including celecoxib, were effective in reducing gastric PGE2 synthesis, administering arthritic rats with ASA resulted in a significant increase in gastric content of aspirin-triggered lipoxin (ATL), a COX-2-derived lipid mediator that regulates proinflammatory responses at the neutrophils/endothelial interface. Administering arthritic rats with naproxen and celecoxib abrogates ATL formation induced by ASA although enhanced neutrophils accumulate into the gastric mucosa (P <0.01 versus ASA alone). In contrast, whereas HCT-3012 inhibited ATL formation, it did not increase neutrophil recruitment into the gastric microcirculation. Collectively, these data indicate that HCT-3012 derived from NO has the potential to compensate for inhibition of PGE2 and ATL and to protect the gastric mucosa by limiting the recruitment of neutrophils. These data suggest that HCT-3012 might be a safer alternative to nonsteroidal anti-inflammatory drugs and coxibs in rheumatic patien

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Experimental; Aspirin; Celecoxib; Cyclooxygenase 1; Cyclooxygenase 2; Eicosanoids; Freund's Adjuvant; Gastric Mucosa; Isoenzymes; Lipoxins; Male; Membrane Proteins; Naproxen; Nitric Oxide; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Pyrazoles; Rats; Rats, Inbred Lew; Reverse Transcriptase Polymerase Chain Reaction; Stomach Ulcer; Sulfonamides

NSAIDs can elevate blood pressure through mechanisms such as renal vasoconstriction and sodium retention. These effects are particularly evident in hypertensive individuals. Nitric oxide-releasing NSAID derivatives have been shown to have greatly reduced toxicity in the gastrointestinal tract and kidney. We therefore evaluated the effects of a 4 week treatment with either naproxen or its nitric oxide-releasing derivative (NO-naproxen) on systemic arterial blood pressure and gastric damage in rats in which hypertension was induced by L-NAME. Rats received either L-NAME dissolved in the drinking water (400 mg/L) or tap water (control). Vehicle, naproxen (10 mg/kg) or an equimolar dose of NO-naproxen (14.5 mg/kg) were administered orally each day. After 4 weeks, blood pressure was measured, blood samples were taken for measurement of thromboxane synthesis, and gastric damage was evaluated by blind, macroscopic scoring. Both naproxen and NO-naproxen inhibited systemic cyclooxygenase activity by >90%. NO-naproxen-treated rats exhibited no significant gastric damage. The gastric damage produced by L-NAME alone was potentiated by naproxen but prevented by NO-naproxen. L-NAME treatment significantly increased blood pressure. In the absence of L-NAME, the naproxen group had significantly higher blood pressure than both the control and NO-naproxen groups. In rats receiving L-NAME, the same conclusions apply, but the concomitant administration of NO-naproxen was able to significantly reduce the blood pressure compared to L-NAME alone. Based on these results, we conclude that NO-naproxen may represent a safer alternative to standard NSAIDs in the treatment of inflammatory conditions in hypertensive patients.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antihypertensive Agents; Gastric Mucosa; Hypertension; Male; Naproxen; NG-Nitroarginine Methyl Ester; Nitric Oxide; Rats; Rats, Wistar; Stomach Ulcer; Thromboxane B2

Naproxen and its derivative nitronaproxen at the doses of 5 and 10 mg kg-1 were compared for their acute anti-inflammatory efficacy in a carrageenan oedema model and gastrointestinal toxicity in rats. Moreover, the effects of the two drugs were evaluated in the adjuvant arthritis, after chronic doses of 4 and 8 mg kg-1 administered orally for 18 days. The oedema reduction was maintained much longer (until 5 h) with nitronaproxen; the inhibition of arthritis was 50% or more with both doses of the examined drugs. From the histological examination of the stomachs, an extensive mucosal vasocongestion and haemorrhagic lesions have been observed in some rats treated with naproxen. The percentages of animals with ulcers were 50, 100 and 10 with naproxen 6 and 18 mg kg-1 and nitronaproxen 54 mg kg-1 respectively. A better gastrointestinal tolerability has been observed in arthritic and oedemic rats treated with nitronaproxen compared to naproxen: this could be due to the presence of nitric oxide that acts in maintaining the tissue perfusion and integrity.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Carrageenan; Digestive System; Disease Models, Animal; Dose-Response Relationship, Drug; Edema; Female; Male; Naproxen; Rats; Rats, Sprague-Dawley; Stomach Ulcer