Indomethacin and naproxen suppositories in the treatment of rheumatoid arthritis

Gellan gum macrobeads loaded with naproxen: The impact of various naturally derived polymers on pH-dependent behavior

Aims

After oral administration, naproxen generates several side-effects related to stomach malfunction. Undoubtedly, the enteric dosage forms with naproxen can be considered as safer. Moreover, since it has been evidenced that development and growth of colorectal cancer is related to the presence of cyclooxygenase, naproxen is investigated in terms of the tumor prevention. The aim of the present work was to formulate and evaluate the properties of novel naproxen-loaded macrobeads, made on the basis of low-acyl gellan gum and its blends with carrageenans, guar gum, cellulose sulfate, and dextran sulfates.

Method

Seven formulations were prepared by ionotropic gelation. The morphology of the dried beads was evaluated by scanning electron microscopy. The next step focused on Raman spectroscopy and thermal analysis of naproxen, polymers, and the beads. Next, the swelling behavior was examined in three acceptor fluids at pH = 1.2; 4.5, and 7.4. The beads were evaluated regarding naproxen content and encapsulation efficiency. The last stage of the work concerned the drug release studies.

Results

Addition of any other polysaccharide than gellan resulted in flattening of the beads upon drying. Differential scanning calorimetry confirmed the crystalline form of naproxen. Raman spectra showed that no apparent interactions occurred. In the acidic environment, all the beads revealed the tendency to absorb water. The beads swelled to the greatest extent at pH = 4.5. Naproxen was released from the beads at a varied rate. At pH = 7.4, the most prolonged release was observed for the beads containing carrageenans.

Conclusions

We have proved that blending of gellan with various polysaccharides can change the pH-dependent properties of the beads loaded with naproxen. We believe that the information enclosed in the paper will be of particular importance regarding the development and characteristics of novel oral dosage forms based on natural polymers.

Clinical and endoscopic features of nonsteroidal anti-inflammatory drug-induced colonic ulcerations

OBJECTIVE

Clinical and endoscopic features of nonsteroidal anti-inflammatory drug (NSAID)-induced colonic ulcerations have not been fully investigated.

METHODS

During a 3-yr period from April 1996 to March 1999, 6076 subjects underwent total colonoscopy at our institutions. Among them, the diagnosis of NSAID-induced colonic ulceration was made by their clinical and colonoscopic findings. All patients diagnosed as having this disease underwent upper endoscopy and follow-up colonoscopy. Clinical features, serial changes in colonoscopic findings, and upper GI lesions were analyzed.

RESULTS

Among the subjects, 14 patients were diagnosed as having NSAID-induced ulcerations. Seven patients were complicated by renal failure. Three patients had gastric ulcers concurrently. Eleven patients had colonic lesions in the ileocecal region. In 13 of 14 patients, initial colonoscopy demonstrated sharply demarcated, semilunar or circumferential ulcers without stricture formation. After discontinuance of NSAIDs, improvement of the ulcers without stricture or inflammatory polyps could be confirmed 3-10 wk later. In one patient with diaphragm-like stricture, follow-up colonoscopy performed 2 yr later demonstrated resolution of circumferential ulcer.

CONCLUSIONS

NSAID-induced colonic ulceration may occur more frequently than previously recognized. Frank ulcerations, rather than stricture formation, seem to be the typical colonoscopic signs of NSAID-induced colonic ulceration.

Gastrointestinal side effects of nonsteroidal anti-inflammatory drugs

The gastrointestinal (GI) tract is the most common location for side effects of nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs may cause problems in any part of the GI tract, from the esophagus to the rectum. The severity of these side effects ranges from nuisance symptoms such as dyspepsia to life-threatening ulcer complications. The diagnosis, treatment, and prevention of the various GI side effects of these commonly prescribed drugs are reviewed in this article.

Zopiclone as night medication in rheumatoid arthritis

Sleep disturbances and related daytime complaints are frequent in rheumatoid arthritis (RA). The aim of the current study was therefore to evaluate the effect of a newer hypnotic on sleep structure and clinical parameters in RA. Forty outpatients were randomized to a two week treatment regimen with either 7.5 mg zopiclone or placebo at bedtime. Clinical examinations were performed before and after treatment and the degree of pain, fatigue, sleepiness, morning stiffness, and activities of daily living were assessed. Two sleep questionnaires were also completed weekly. Polysomnography was performed before the study and after 14 days of treatment. Recordings were evaluated using conventional sleep scoring as well as frequency analysis of the electroencephalography (EEG). Patients in the zopiclone group had subjective improvement of sleep, but otherwise no differences in pain score or the other clinical parameters were found. Conventional sleep assessments showed only minor changes during treatment, but frequency analysis demonstrated a shift from the lower towards the higher EEG frequencies in the active treatment group. Although the modulation of the EEG can represent a non-specific pharmacologic epiphenomenon, it might also reflect a disturbance of sleep microstructure. In conclusion, treatment with zopiclone may be of value for subjective sleep complaints in selected patients with RA, but it is doubtful whether hypnotics improve daytime symptoms in this patient group.

Clinical pharmacokinetics of naproxen

Naproxen is a stereochemically pure nonsteroidal anti-inflammatory drug of the 2-arylpropionic acid class. The absorption of naproxen is rapid and complete when given orally. Naproxen binds extensively, in a concentration-dependent manner, to plasma albumin. The area under the plasma concentration-time curve (AUC) of naproxen is linearly proportional to the dose for oral doses up to a total dose of 500 mg. At doses greater than 500 mg there is an increase in the unbound fraction of drug, leading to an increased renal clearance of total naproxen while unbound renal clearance remains unchanged. Substantial concentrations of the drug are attained in synovial fluid, which is a proposed site of action for nonsteroidal anti-inflammatory drugs. Relationships between the total and unbound plasma concentration, unbound synovial fluid concentration and therapeutic effect have been established. Naproxen is eliminated following biotransformation to glucuroconjugated and sulphate metabolites which are excreted in urine, with only a small amount of the drug being eliminated unchanged. The excretion of the 6-O-desmethylnaproxen metabolite conjugate may be tied to renal function, as accumulation occurs in end-stage renal disease but does not appear to be influenced by age. Hepatic disease and rheumatoid arthritis can also significantly alter the disposition kinetics of naproxen. Although naproxen is excreted into breast milk the amount of drug transferred comprises only a small fraction of the maternal exposure. Significant drug interactions have been demonstrated for probenecid, lithium and methotrexate.

NSAID-induced gastrointestinal damage. Epidemiology, risk and prevention, with an evaluation of the role of misoprostol. An Asia-Pacific perspective and consensus

The problem of nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal toxicity was reviewed by members of the Asia Pacific League of Associations for Rheumatology (APLAR) in a consensus conference in September 1992. This paper by the participants presents the consensus conclusions incorporating knowledge from recent publications. There had been a high level of concern that much of the toxicity had resulted from extensive and indiscriminate prescribing of NSAIDs. The implementation of evidence-based guidelines was considered likely to be able to effect a substantial reduction in toxicity without significant loss of overall therapeutic benefit. The evidence from which such guidelines could be developed is critically appraised.

Toxicity of nonsteroidal anti-inflammatory drugs in the large intestine

PURPOSE

Adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDS) on the upper gastrointestinal (GI) tract and small intestine are well described. Evidence is also accumulating that implicate NSAIDS in inducing and exacerbating damage in the distal GI tract. The purpose of this review is to identify possible adverse effects of NSAIDS on the large intestine and increase the clinical awareness of these toxicologic effects.

METHODS

A literature review identified the diversity of toxicologic effects induced by NSAIDS in the large intestine. The epidemiology, pathogenesis, and clinical implications of these adverse effects are described.

RESULTS

NSAID use has been associated with colonic bleeding, iron deficiency anemia, strictures, ulcerations, perforations, diarrhea, and death. In addition, NSAIDS can exacerbate inflammatory bowel disease and ulcerative colitis. The prevalence of NSAID-induced large intestinal damage is unknown. Diagnosis can be made by colonoscopy and barium scans. Although the clinical presentation of NSAID-induced gastropathy and enteropathy, bleeding or perforation, may be more dramatic than colonopathy, the overall clinical significance of these adverse effects of NSAIDS on the large intestine has not been fully characterized.

CONCLUSIONS

This review illustrates that NSAID-induced large bowel toxicity can cause significant morbidity in some patients, ranging from profuse diarrhea, chronic blood loss, and iron deficiency anemia to fatality. The pathogenesis is likely multifactorial and is thought to be related to inhibition of prostaglandin synthesis. Because NSAIDS are widely prescribed and some are available without a prescription, heightened awareness of these toxicologic manifestations throughout the GI tract may reduce morbidity.

Increased production of luminol enhanced chemiluminescence by the inflamed colonic mucosa in patients with ulcerative colitis

Reactive oxygen species have been implicated as mediators of inflammation in ulcerative colitis. Chemiluminescence is a reliable means of estimating reactive oxygen species in biological media. Increased reactive oxygen species values in the inflamed colonic mucosa in rats were seen by chemiluminescence. The aims of the study were to find out if chemiluminescence is raised in the colonic mucosa of patients with ulcerative colitis and correlates with disease activity, and to elucidate the sources of the chemiluminescence. It was found that reactive oxygen species, as measured by the chemiluminescence technique, are raised in inflamed colonic mucosa and correlates with symptom score, sigmoidoscopic score, disease activity, and activity of the neutrophil enzyme myeloperoxidase. Chemiluminescence was inhibited by a myeloperoxidase inhibitor (azide) and an H2O2 scavenger (catalase) but not by allopurinol, an inhibitor of the enzyme xanthine oxidase. Chemiluminescence was also inhibited by indomethacin, but this did not seem to be related to inhibition of cyclo-oxygenase. These findings suggest that a likely cellular source of reactive oxygen species in the inflamed colon of patients with ulcerative colitis is the neutrophil and that myeloperoxidase conversion of H2O2 to hypochlorous acid, contributes to the chemiluminescence signal and possibly, to the tissue injury. Neither cyclo-oxygenase nor lipoxygenase seem to play a part as sources for the chemiluminescence.

Side effects of nonsteroidal anti-inflammatory drugs on the small and large intestine in humans

BACKGROUND

It is not widely appreciated that nonsteroidal anti-inflammatory drugs (NSAIDs) may cause damage distal to the duodenum. We reviewed the adverse effects of NSAIDs on the large and small intestine, the clinical implications and pathogenesis.

METHODS

A systematic search was made through Medline and Embase to identify possible adverse effects of NSAIDs on the large and small intestine.

RESULTS

Ingested NSAIDs may cause a nonspecific colitis (in particular, fenemates), and many patients with collagenous colitis are taking NSAIDs. Large intestinal ulcers, bleeding, and perforation are occasionally due to NSAIDs. NSAIDs may cause relapse of classic inflammatory bowel disease and contribute to serious complications of diverticular disease (fistula and perforation). NSAIDs may occasionally cause small intestinal perforation, ulcers, and strictures requiring surgery. NSAIDs, however, frequently cause small intestinal inflammation, and the associated complications of blood loss and protein loss may lead to difficult management problems. The pathogenesis of NSAID enteropathy is a multistage process involving specific biochemical and subcellular organelle damage followed by a relatively nonspecific tissue reaction. The various possible treatments of NSAID-induced enteropathy (sulphasalazine, misoprostol, metronidazole) have yet to undergo rigorous trials.

CONCLUSIONS

The adverse effects of NSAIDs distal to the duodenum represent a range of pathologies that may be asymptomatic, but some are life threatening.

Excessive production of reactive oxygen metabolites by inflamed colon: analysis by chemiluminescence probe

Reactive oxygen metabolites (ROMs) are involved in inflammatory diseases and are postulated to contribute to tissue injury in colitis. To determine whether excessive ROMs are generated by inflamed colonic mucosa and to identify possible sources and type of ROMs, mucosal ROMs were estimated in rats and humans using a chemiluminescence probe. Colitis was induced in rats by intracolonic injection of acetic acid or intraperitoneal injection of mitomycin C. Intact, inflamed colon in rats produced more ultraweak chemiluminescence than normal colon. Inflamed mucosal scrapings from both rat models produced significantly more luminol-enhanced chemiluminescence. Addition of catalase, an H2O2 scavenger, or azide, a myeloperoxidase inhibitor, into the media significantly decreased chemiluminescence from inflamed mucosal scrapings. Indomethacin, an antioxidant cyclo-oxygenase inhibitor, also decreased chemiluminescence, but MK-866, a 5-lipoxygenase inhibitor, had no effect. Colonic biopsy specimens obtained during colonoscopy from patients with ulcerative colitis also produced more catalase-inhibitable chemiluminescence than normal colonic mucosa. These data indicate that excessive ROMs are produced by inflamed colonic mucosa in both humans and rats, which may contribute to tissue injury.

Review article: non-steroidal, anti-inflammatory drugs--the extending scope of gastrointestinal side effects

The gastrointestinal side effects of non-steroidal, anti-inflammatory drugs extend beyond the duodenal bulb, and comprise a variety of lesions in all parts of the gut. Gastroduodenal ulceration is quantitatively dominant, although a major part of these lesions probably go unnoticed and heal spontaneously. Adaptation has been demonstrated for acetylsalicylic acid, and may be of importance for other substances as well. Non-steroidal anti-inflammatory drugs (NSAIDs) may induce relapse of inflammatory bowel disease. Permeability changes and mucosal inflammation are found in the small and large bowel in the majority of subjects taking NSAIDs, although the clinical significance is still not clear. Ulceration and perforation do, however, occur in this part of the gut as well. Treatment of NSAID-associated ulceration is similar to traditional ulcer treatment, possibly with extended treatment duration if the NSAID is continued. Prophylaxis is of some value, but is not required for every patient receiving an NSAID.

Matching the Drug to the Patient: The rational use of antiarthritic drugs

Antirheumatic drugs now available are often effective in helping control the more serious rheumatic disorders, but are not curative. All have potentially serious side effects and need to be used with caution in the presence of recognized risk factors. Treatment should be individualized for the diagnosis and severity of the underlying disease, which must be of sufficient magnitude to justify the risk of potential adverse reactions from the prescribed medication.

Prostaglandins in the gut and their relationship to non-steroidal anti-inflammatory drugs

Prostaglandins are long-chain, saturated, oxygenated fatty acids. Relatively large quantities of prostaglandins have been found in gut mucosa, suggesting that these substances play an important role in gastrointestinal physiology. Non-steroidal anti-inflammatory drugs (NSAIDs) cause damage to the gastric, intestinal, and colonic mucosa in experimental animals and in humans. Prostaglandins protect the gastric mucosa against injury induced by NSAIDs, and this property has been labelled cytoprotection. The mechanisms of cytoprotection have been extensively evaluated and are probably multifactorial, including effects on the gastric mucosal barrier, gastric blood flow, mucus, bicarbonate, and fluid section, ionic transport, cyclic AMP, and surface-active phospholipids. Prostaglandins may also prevent NSAID-induced injury in the small intestine and colon. The mechanisms responsible for prostaglandin protection in the lower gut against injurious agents are unknown. Further studies of the role of prostaglandins in the gut and their relationship to the effects of NSAIDs are needed. The results of these investigations may lead to a better understanding of the importance of prostaglandins in the physiology of the gastrointestinal tract, and may provide information regarding actions of NSAIDs on the functional integrity of the gastric, intestinal, and colonic mucosa.

The changing gastrointestinal side effect profile of non-steroidal anti-inflammatory drugs. A new approach for the prevention of a new problem

The most serious side effects of non-steroidal anti-inflammatory drugs (NSAIDs) involve gastroduodenal perforations and massive haemorrhage. It is becoming increasingly clear, however, that it is the small intestine that bears the main brunt of NSAID-related gastrointestinal toxicity. Hence 70% of patients receiving NSAIDs in the long term have evidence of small-intestinal inflammation, and the same patients lose blood and protein as a consequence. Many patients have asymptomatic ileal dysfunction and occasionally may develop unique small-intestinal strictures necesitating surgery. The pathogenesis of the intestinal inflammation is beginning to emerge. There are data to support that an imbalance between prostaglandins and leukotrienes is important in disrupting small-intestinal integrity during drug absorption. Furthermore, a simple mixture of glucose and citrate with indomethacin appears to minimize the damage. Whether this overcomes a metabolic block caused by NSAIDs and replenishes ATP levels or acts by scavenging oxygen free radicals is unknown, but our further understanding of the mechanism may revolutionize our approach to prevention of the gastrointestinal toxicity of NSAIDs.

Role of eicosanoids in human and experimental colitis

Prostaglandins, thromboxanes, and leukotrienes (collectively called eicosanoids) are increased at sites of inflammation and contribute to the manifestations of inflammation, such as hyperemia, hyperalgesia, edema, and inflammatory cell infiltration. Inhibition of eicosanoid production is the basic mechanism of action of corticosteroids and of nonsteroidal antiinflammatory drugs. Eicosanoid synthesis is also increased in human and experimental inflammatory bowel disease. Leukotriene B4 is the most potent proinflammatory eicosanoid, and in vivo production of this compound is the predominant eicosanoid in colitis. Recent experimental data demonstrate that selective inhibition of leukotrienes may be a therapeutic strategy to reduce inflammation in inflammatory bowel disease.

Nonsteroidal antiinflammatory drugs and aspirin--analyzing the scores

We reviewed 103 controlled clinical trials that compared the antiarthritic efficacy and tolerance of previously and currently marketed nonsteroidal antiinflammatory drugs (NSAIDs) and aspirin. Of 52 studies, 35 had data sufficient to calculate an NSAID efficacy index (the ratio of mean improvement in NSAID-treated patients to that in aspirin-treated patients) based on subjective and/or objective criteria. The mean indexes (obtained from all studies from which an index could be calculated) indicated no statistically significant difference in efficacy between aspirin and the NSAIDs as a group; the indexes tended to become less variable as the number of study subjects increased. Tolerance, assessed from the percentage of patients who discontinued the drug because of side effects, was significantly greater for NSAIDs than for aspirin. The NSAIDs had greater efficacy but not greater toxicity at increased doses. Efficacy differences described among NSAIDs in some studies were attributable either to comparisons at nonequivalent doses or to chance.

Are prostaglandins cytoprotective in the human large intestine? The effect of indomethacin on rectal mucosal function and prostaglandin E2 release in vivo

To test the hypothesis that prostaglandins are cytoprotective in the human large intestine, we investigated the effect of withdrawal of treatment with indomethacin suppositories on bowel habit and on rectal mucosal electrolyte transport and prostaglandin production in 8 patients taking such treatment for rheumatological disorders. Discontinuation of indomethacin doubled rectal mucosal prostaglandin E2 release (p less than 0.05) measured by in vivo rectal dialysis. Although there was no significant overall change in stool frequency, stool consistency, rectal bleeding or sodium absorption (also assessed by rectal dialysis), sigmoidoscopic appearance (p = 0.05), rectal mucosal potential difference (p less than 0.05) and potassium transport (p = 0.01) each reverted towards normal on indomethacin withdrawal. These results accord with the theory that, as in the upper gastrointestinal tract, prostaglandins may play a role in the maintenance of rectal mucosal structure and function.

Indomethacin in rheumatoid arthritis: comparison of oral and rectal dosing

1 Indomethacin 100 mg nightly for 1 week has been administered to 13 patients with rheumatoid arthritis by both oral and rectal routes in a double-blind, randomized, cross-over study. 2 Clinical assessments were performed at 09.00 and 14.00 h on the last 3 days of each active treatment period and compared to the results on the last 2 days of the placebo control period. 3 Indomethacin produced significant improvements in the clinical assessments at both 09.00 and 14.00 h compared to placebo but not differences were seen between the two routes of administration. 4 No significant difference was seen in the side effects experienced in the two periods. 5 The mean (+/- s.e. mean) plasma indomethacin concentration at 09.00 h in the oral period was 200.3 +/- 27.4 ng/ml, not significantly different from that in the suppository period (220.0 +/- 28.9 ng/ml). 6 Indomethacin 100 mg nightly by mouth is as effective as a 100 mg suppository and easier to administer.

Naproxen suppositories in combination with oral naproxen, indomethacin and ibuprofen in the treatment of rheumatoid arthritis

A single-blind, crossover trial was carried out in 30 rheumatoid arthritis patients to compare the effectiveness and tolerance of 250 mg naproxen, 400 mg ibuprofen and 25 mg indomethacin twice daily in patients treated concurrently with a night-time 500 mg naproxen suppository. Each day-time drug was given for 3 weeks. Naproxen suppositories were used for the whole 9 weeks of the study. No difference between the combination treatments was seen in pain and morning stiffness, while articular index and P.I.P. joint size tended to improve most during the naproxen tablet and suppository phase. Patients' and physician's preferences were both significantly in favour of the naproxen tablet and suppository phase. Side-effects were similar during all treatment phases, except for vertigo which occurred during the indomethacin capsule and naproxen suppository phase. Combinations of two non-steroidal, anti-inflammatory drugs have been shown to be effective and well tolerated but to have no advantage over treatment with only one drug. Naproxen suppositories have been shown to be well tolerated over a 9-week period.

Naproxen up to date: a review of its pharmacological properties and therapeutic efficacy and use in rheumatic diseases and pain states

Naproxen is a propionic acid derivative with analgesic and anti-inflammatory activity which has been widely used in the treatment of rheumatic diseases. Naproxen has been well studied in rheumatoid arthritis and is as effective as aspirin but better tolerated, thus enabling more patients to continue with treatment. For this reason some clinicians now prefer to try propionic acid derivatives, such as naproxen, before aspirin in arthritic patients. In comparative studies with other non-steroidal anti-inflammatory drugs, such as indomethacin, ibuprofen, fenoprofen and others, all drugs were usually of similar overall efficacy although naproxen was sometimes preferred: but as with other non-steroidal anti-inflammatory agents, not all patients will respond to naproxen and in such cases other agents should also be tried until the most satisfactory drug is found for each patient. Naproxen is also effective in degenerative joint diseases of the hip and knee, although further well designed studies are needed to more clearly define its relative place compared with newer drugs such as diclofenac or diflunisal. Results of other comparative studies have shown that naproxen is a suitable alternative to phenylbutazone or indomethacin in ankylosing spondylitis and to aspirin in juvenile rheumatoid arthritis. Naproxen appears to be effective in reducing pain and swelling in acute gout and is an effective analgesic in patients with pain following surgery or trauma and in pain of dysmenorrhoea. Naproxen has generally been better tolerated than aspirin or indomethacin at the dosages used. Because of its relatively long plasma half-life, naproxen can with convenieice be given twice daily, and there is some evidence that once daily dosage is as effective in rheumatoid arthritis.