Variability in risk of gastrointestinal complications with individual non-steroidal anti-inflammatory drugs: results of a collaborative meta-analysis

[New nonsteroidal anti-inflammatory agents: nitric oxide donors and selective cyclooxygenase-2 inhibitors]

The use of non steroidal anti-inflammatory drugs as analgesic or anti-inflammatory agents is primarily limited by their toxicity to the gastrointestinal tract. Two strategies have been developed recently in order to improve the safety of these drugs. The first approach is the linking of a nitric oxide-releasing moiety to the available compounds. The rationale is that nitric oxide may prevent non steroidal anti-inflammatory drugs-induced ulcerations by preventing mucosal ischemia. The second approach is based on the discovery of two isoforms (COX-1 and COX-2) of the cyclo-oxygenase enzyme. It was hypothesized that the constitutively expressed COX-1 isoenzyme leads to the synthesis of prostaglandins with homeostatic functions whereas COX-2 is merely responsible for the production of prostaglandins mediating pain, fever and inflammation. Accordingly, selective COX-2 inhibitors have been developed. Clinical trials indicate that these compounds are roughly as effective as the available non steroidal anti-inflammatory agents without causing acute gastrointestinal damage. There is some evidence that both COX-1 and COX-2 isoforms are involved in the production of prostaglandins associated with inflammation and homeostatic functions. Finally, the true benefit/risk ratio of these new non steroidal anti-inflammatory drugs remains to be assessed.

Selective cyclooxygenase-2 inhibitors for the treatment of arthritis

The purpose of this paper is to review the rationale for a new class of nonsteroidal anti-inflammatory drugs (NSAIDs) known as selective cyclooxygenase (COX)-2 inhibitors and to present preliminary clinical data on 2 COX-2 inhibitors that are approved for use in the United States. The primary mechanism of NSAIDs in the treatment of inflammation is the inhibition of COX, which exists in 2 forms. COX-I appears to regulate many normal physiologic functions, and COX-2 mediates the inflammatory response. Theoretically, an NSAID that inhibits COX-2 selectively should decrease inflammation but not influence normal physiologic functions and thus should cause fewer gastrointestinal side effects. Preliminary data suggest that celecoxib, a highly selective COX-2 inhibitor, is superior to placebo and similar to traditional NSAIDs in the short-term treatment of pain due to osteoarthritis, although it has been associated with adverse effects such as headache, change in bowel habits, abdominal discomfort, and dizziness. Celecoxib also has been shown to be as effective as traditional NSAIDs in the treatment of rheumatoid arthritis, but it may cause fewer adverse effects, including endoscopically documented ulcers. Celecoxib is metabolized in the liver by the cytochrome P-450 isozyme CYP2C9, and thus serious drug interactions are possible. In the treatment of osteoarthritis, rofecoxib has been shown to be as effective as traditional NSAIDs and may cause fewer endoscopically documented ulcers, but its complete adverse-effect profile is not known. Until the selective COX-2 inhibitors are widely used and more clinical as well as pharmacoeconomic studies are published, the exact role of COX-2 therapy cannot be determined. words: cyclooxygenase, celecoxib, rofecoxib, rheumatoid arthritis, osteoarthritis.

Gastrointestinal safety and tolerance of ibuprofen at maximum over-the-counter dose

BACKGROUND

Delineation of non-steroidal anti-inflammatory drug (NSAID) gastrointestinal toxicity has largely depended on retrospective epidemiologic studies which demonstrate that lower doses of NSAIDs pose a lower risk of gastrointestinal toxicity. Ibuprofen, a propionic acid NSAID, has, in most such studies, exhibited a favourable profile in terms of gastrointestinal bleeding. Since 1984, ibuprofen has been available as a non-prescription analgesic/antipyretic with a limit of 1200 mg/day for 10 days of continuous use. Trials and spontaneously reported adverse experiences suggest that gastrointestinal symptoms and bleeding are rare.

METHODS

This study prospectively evaluated the gastrointestinal tolerability, as compared to placebo, of the maximum non-prescription dose and duration of ibuprofen use in healthy subjects representative of a non-prescription analgesic user population.

RESULTS

Gastrointestinal adverse experiences were similar in the placebo and ibuprofen groups (67 out of 413, 16% with placebo vs. 161 out of 833, 19% with ibuprofen). There was no difference between the two groups in the proportion discontinuing due to a gastrointestinal event. Gastrointestinal adverse experiences reported by >/= 1% of subjects were: dyspepsia, abdominal pain, nausea, diarrhoea, flatulence, and constipation. Seventeen (1.4%) subjects had positive occult blood tests: their frequency was comparable between treatments.

CONCLUSIONS

When used as directed to treat episodic pain, non-prescription ibuprofen at the maximum dose of 1200 mg/day for 10 days, is well-tolerated.

Low-dose diclofenac, naproxen, and ibuprofen cohort study

The risk of a newly diagnosed episode of upper gastrointestinal bleeding, acute liver and renal failure, agranulocytosis, aplastic anemia, severe skin disorders, and anaphylaxis was examined within 30 days after the first prescription for a low dose of diclofenac, naproxen, or ibuprofen in a cohort in the United Kingdom. We identified 22,146 persons using diclofenac (< or = 75 mg), 46,919 using naproxen (< or = 750 mg), and 54,830 using ibuprofen (< or = 1200 mg). Age, gender, and comorbidity were similar in the three cohorts. Overall 64 potential cases were identified, and 20 were confirmed by medical record review. Incidence rates (95% CI) of upper gastrointestinal bleeding/10,000 people using diclofenac, naproxen, and ibuprofen were 1.8 (0.5-4.6), 2.3 (1.2-4.2), and 0.4 (0.04-1.3), respectively. There were three cases of hepatic injury, one with naproxen and two with ibuprofen. Although low, the incidence of gastrointestinal toxicity remains the main serious adverse event for all study drugs.

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.

Nonsteroid drug selectivities for cyclo-oxygenase-1 rather than cyclo-oxygenase-2 are associated with human gastrointestinal toxicity: a full in vitro analysis

The beneficial actions of nonsteroid anti-inflammatory drugs (NSAID) can be associated with inhibition of cyclo-oxygenase (COX)-2 whereas their harmful side effects are associated with inhibition of COX-1. Here we report data from two related assay systems, the human whole blood assay and a modified human whole blood assay (using human A549 cells as a source of COX-2). This assay we refer to as the William Harvey Modified Assay. Our aim was to make meaningful comparisons of both classical NSAIDs and newer COX-2-selective compounds. These comparisons of the actions of >40 NSAIDs and novel COX-2-selective agents, including celecoxib, rofecoxib and diisopropyl fluorophosphate, demonstrate a distribution of compound selectivities toward COX-1 that aligns with the risk of serious gastrointestinal complications. In conclusion, this full in vitro analysis of COX-1/2 selectivities in human tissues clearly supports the theory that inhibition of COX-1 underlies the gastrointestinal toxicity of NSAIDs in man.

Effect of clopidogrel on naproxen-induced gastrointestinal blood loss in healthy volunteers

The effect of clopidogrel, a potent inhibitor of platelet aggregation, on naproxen-induced faecal blood loss was investigated in 30 healthy volunteers in a randomized, double-blind, placebo-controlled, two parallel treatment groups study. All subjects first received naproxen 250 mg b.i.d. during 7 days, after which they were randomly allocated to additionally receive either clopidogrel 75 mg once daily (n = 15) or matching placebo (n = 15) for 11 days. Faecal blood loss was measured by the 51Cr-labelled erythrocyte method during the last four days of each of the four study periods, i.e. baseline, treatment with naproxen alone, combined treatment and wash-out. Mean daily faecal blood loss was below 0.5 ml/day during the baseline period in both treatment groups and increased during treatment with naproxen alone to (mean +/- SD) 1.14 +/- 0.58 ml/day in the naproxen + placebo group and to 1.93 +/- 1.51 ml/day in the naproxen + clopidogrel group. Addition of clopidogrel to naproxen treatment was associated with an increase of the mean daily blood loss to 6.83 +/- 9.32 ml/day, which was statistically significantly higher than 1.75 +/- 1.40 ml/day observed during treatment with naproxen + placebo. During the wash-out period, mean daily blood loss decreased to 0.98 +/- 0.51 ml/day in the naproxen + placebo group and to 1.07 +/- 0.46 ml/day in the naproxen + clopidogrel group. Based on these results, it can be concluded that clopidogrel increases naproxen-induced gastrointestinal blood loss in healthy volunteers. Caution should therefore be called for when these drugs are coadministered.

An endoscopic study of gastroduodenal lesions induced by nonsteroidal anti-inflammatory drugs

Rheumatoid arthritis (RA) and osteoarthritis (OA) are frequently treated with nonsteroidal anti-inflammatory drugs (NSAIDs). Although NSAIDs are an effective therapy for the pain and inflammation of arthritis, they are associated with serious side effects, particularly ulceration, bleeding, and perforation of the gastrointestinal (GI) tract. In this study, 1826 OA or RA patients who either had been taking NSAIDS for > or =6 months or had been unable to tolerate continuous NSAID use because of adverse GI symptoms or suspected NSAID-related gastroduodenal lesions were examined endoscopically for gastroduodenal lesions and ulcers. At the same time, the patients were asked to rate the severity of any GI symptoms they had been experiencing. Of the total number of patients studied, 817 (44.7%) were OA patients with a mean (+/- SD) age of 55.8+/-12.9 years, and 1009 (55.3%) were RA patients with a mean age of 53.1+/-13.1 years. Clinically significant gastroduodenal lesions were found in 37.1% of patients (n = 678); of these, 24.0% (n = 439) had ulcers. Gastric ulcers were more frequent than duodenal ulcers (14.8% vs 10.2% of patients; P < 0.05), and most gastric ulcers (72.0%) were found in the antrum of the stomach. The prevalence of gastroduodenal ulcers increased with age (P < 0.001), duration of OA (P < 0.001), and duration of current NSAID use (P = 0.019). The prevalence of gastroduodenal ulcers in patients taking NSAIDs for <1 year was 13.8%, compared with a nearly twofold higher prevalence (25.9%) in patients taking NSAIDs for periods of > or =1 year and up to 15 years. The prevalence of gastric ulcers was 32.6% in patients with a history of gastric ulcer but only 13.5% in patients with no GI history (previous gastric ulcer, duodenal ulcer, or upper GI hemorrhage). No relationship was found between the prevalence of gastroduodenal ulcers and sex (men, 22.4%; women, 24.9%) or prevalence of gastroduodenal ulcers and type of arthritic disease (RA, 23.6%; OA, 24.5%). The prevalence of gastroduodenal ulcers increased with the severity of GI symptoms (P = 0.007). These results provide further endoscopic confirmation of the association between NSAID use and gastroduodenal lesions and ulcers and support the contention that safer treatment alternatives to conventional NSAIDs are required.

Preventing NSAID Toxicity to the Upper Gastrointestinal Tract

Prevention of gastrointestinal toxicity begins with the selection of an appropriate analgesic or anti-inflammatory agent. For conditions without inflammation, such as some cases of osteoarthritis, an analgesic with no risk for gastrointestinal toxicity is appropriate. Risk factors for nonsteroidal anti-inflammatory drug (NSAID)-related complications include advanced age; history of ulcer disease or gastrointestinal bleeding; concomitant corticosteroid or anticoagulant use; use of high-dose or multiple NSAIDs; and certain chronic diseases, such as cardiovascular disease. If an NSAID must be used in a patient with risk factors, the patient should receive the lowest-risk NSAID and, in most cases, co-therapy to reduce the risk for NSAID-associated ulcers and their complications. The PGE1 prostaglandin analogue misoprostol is highly efficacious for the prevention of both gastric and duodenal ulcers and has also been shown to reduce the incidence of NSAID-induced ulcer complications. Side effects, such as diarrhea, may limit patient acceptance of the drug. Acid suppression with traditional ulcer-healing doses of H2-blockers significantly reduces rates of duodenal ulcer but is ineffective in reducing gastric ulceration. More potent acid inhibition with double-dose H2-blockers reduces rates of both gastric and duodenal ulcers. Proton-pump inhibitors, such as omeprazole, have been shown to prevent gastric and duodenal ulcers with an efficacy equal to that of misoprostol. They also reduce NSAID-related dyspepsia. Specific cyclooxygenase-2 (COX-2) inhibitors are associated with a markedly reduced rate of endoscopic ulcers. Very high-risk patients who receive these agents may still require co-therapy to prevent complications or reduce dyspepsia. This protocol may be changed by the results of long-term gastrointestinal outcome studies now underway.

Lower body osteoarticular pain and dose of analgesic medications in older disabled women: the Women's Health and Aging Study

OBJECTIVES

This study assessed use and dosage of analgesic medications in relation to severity of osteoarticular pain.

METHODS

The type and dose of analgesic medication and the severity of pain in the lower back, hips, knees, or feet of 1002 older disabled women were assessed.

RESULTS

Severe pain and the use of analgesic medications were reported by 48.5% and 78.8% of women, respectively. Among those who had severe pain, 41.2% were using less than 20% of the maximum analgesic dose. Overall, 6.6% of women were using more than 100% of the maximum dose.

CONCLUSIONS

Severe pain is common. Additional, more effective, and safe analgesic treatments are needed for controlling pain in older persons.

Prophylaxis and treatment of NSAID-induced gastroduodenal disorders

A significant percentage of patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) experience some type of adverse gastrointestinal symptoms, lesions of the gastroduodenal tract being clinically the most relevant. NSAIDs cause gastrointestinal damage by 2 independent mechanisms: a topical effect, which is pH and pKa related, and a systemic effect mediated by cyclooxygenase (COX) inhibition with a reduction in prostaglandin synthesis. Using endoscopy, gastroduodenal lesions identified include subepithelial haemorrhages, erosions and ulcers. The prevalence of ulceration in NSAID users has been reported as being between 14 and 31% with a 2-fold higher frequency of gastric ulcers compared with duodenal ulcers. Among the strategies used to decrease the risk of ulcer development are: (i) the use of analgesics other than NSAIDs; (ii) use of the lowest possible dosage of NSAID; (iii) the use of a COX-2 selective NSAID; (iv) the use of low doses of corticosteroids instead of NSAIDs; (v) avoidance of concomitant use of NSAIDs and corticosteroids; and (vi) use of preventive therapy. In an attempt to reduce the incidence of NSAID-induced gastrointestinal lesions, the following approaches have been proposed: (i) use of the prostaglandin analogue misoprostol, which is an antiulcer drug which has been proven to be as effective in the prevention of NSAID-induced gastric and duodenal ulcers as in the reduction of serious upper gastrointestinal complications; (ii) histamine H2 receptor antagonists (H2 antagonists), e.g. ranitidine, cimetidine and famotidine, which are useful in the prevention of NSAID-induced duodenal ulcers during long term treatment, but not in the prevention of NSAID-induced gastric ulcers; (iii) proton pump inhibitors, e.g omeprazole, and pantoprazole, whose efficacy in preventing NSAID-associated ulcers has been recently demonstrated; and (iv) barrier agents, e.g. sucralfate, which cannot be recommended as prophylactic agents to prevent NSAID-induced gastropathy. The first step in the treatment of NSAID-associated ulcers lies in a reduction in the dosage of the NSAID or discontinuation of the drug. If NSAID treatment cannot be withdrawn, a proton pump inhibitor appears to be the most effective treatment in healing ulcers, accelerating the slow healing observed with H2 antagonists.

Gastrointestinal effects of nonsteroidal anti-inflammatory therapy

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for the treatment of many conditions including rheumatoid arthritis, osteoarthritis, gouty arthritis, the joint and muscle discomfort associated with systemic lupus erythematosus, and other musculoskeletal disorders. Yet, their benefits, which are believed to be a result of their ability to inhibit cyclooxygenase-2 (COX-2), are accompanied by considerable toxicity. NSAIDs' untoward effects are attributed to their inhibition of the constitutively expressed enzyme cyclooxygenase-1 (COX-1), with attendant suppression of the synthesis of prostanoids, substances that mediate key homeostatic functions. Side effects include suppression of hemostasis through inhibition of platelet aggregation, adverse effects in patients with heart failure and cirrhosis, and those with certain renal diseases, as well as complicating antihypertensive therapies involving diuretics or beta-adrenoceptor blockade. Perhaps most importantly, NSAIDs disrupt the gastrointestinal mucosal-protective and acid-limiting properties of prostaglandins, frequently leading to upper gastrointestinal erosions and ulceration, with possible subsequent hemorrhage and perforation. These complications can be reduced through identification of patients at risk, with circumspect use of NSAIDs, careful functional monitoring, and, in the case of gastrointestinal toxicity, co-administration of such agents as misoprostol or omeprazole. However, these strategies introduce complexity into the treatment paradigm. Moreover, side effects and adverse events may be significantly reduced through the use of COX-2-specific inhibitors, new agents that alleviate pain and inflammation without the liability for adverse events caused by COX-1 inhibition.

Ex vivo assay to determine the cyclooxygenase selectivity of non-steroidal anti-inflammatory drugs

1. In this study we describe experiments to establish ex vivo the selectivity of non-steroidal anti-inflammatory drugs (NSAIDs) given in vivo. 2. Anaesthetised (Inactin, 120 mg kg(-1)) male Wistar rats (220-250 g) received an i.v. dose of one of the following compounds (dose mg kg(-1)): aspirin (20), diclofenac (3), L-745,337 (30), nimesulide (15), salicylate (20), sulindac (10). Blood samples were taken before and up to 6 h after dosing and the plasma obtained from it was tested for its ability to inhibit prostanoid formation in IL-1beta-treated A549 cells (COX-2 system) and human washed platelets (COX-1 system). For control the same compounds were also added directly to the assay systems. 3. All drugs, except sodium salicylate, inhibited COX-1 and COX-2 when added directly to the test systems. Plasma from aspirin-treated rats was without effect on either COX-1 or COX-2, consistent with the rapid in vivo metabolism to salicylate. Conversely, plasma from sulindac-treated rats inhibited COX-1 and COX-2 with potencies according with in vivo metabolism to sulindac sulphide. Diclofenac was COX-1/2 non-selective when tested in vitro, but a slightly preferential inhibitor of COX-2 when tested ex vivo. Nimesulide was confirmed as preferential inhibitor of COX-2 both in vitro and ex vivo. L-745,337 was a selective COX-2 inhibitor when tested in vitro or ex vivo. 4. In conclusion, our experiments show clearly (a) NSAIDs inactivation, (b) activation of prodrugs, and (c) NSAIDs selectivity. Our assay provides useful information about the selectivity of NSAIDs that could be extended by the analysis of plasma samples taken from humans similarly treated with test drugs.

The use of analgesics in the management of pain in rheumatic diseases

Pain is the most common complaint of patients who see rheumatologists. In this article, the current treatment options for pain are reviewed; these include acetaminophen, nonsteroidal anti-inflammatory drugs, new specific cyclooxygenase-2 inhibitors, opioid analgesics, centrally acting muscle relaxants, antidepressants, and topical analgesics and counterirritants. The doses of medication and known adverse effects of these medications are highlighted.

Analgesic efficacy of a combination of hydrocodone with ibuprofen in postoperative pain

Two randomized, double-blind, parallel-group single-dose 2 x 2 factorial analgesic studies compared a single-dose or a 2-tablet dose of a combination of 7.5 mg hydrocodone bitartrate with 200 mg ibuprofen with each constituent alone and with a placebo in women with moderate or severe postoperative pain from abdominal or gynecologic surgery. A nurse-observer recorded patient reports of pain intensity and pain relief periodically for 8 hours. In both studies, the combination was significantly superior to placebo for sum of the pain intensity differences (SPID), total pain relief (TOTPAR), peak pain intensity difference (PID) and pain relief, global evaluation, and time to remedication. The combination was likewise significantly superior to both hydrocodone and ibuprofen for most of these summary measures of analgesia. In a factorial analysis, both the hydrocodone and ibuprofen effects were significant for most summary measures of analgesia, whereas results of the interaction contrast were consistent with the concept that the analgesic effect of the combination represents the additive analgesia of its 2 constituents.

Chemoprevention of intestinal adenomas in the ApcMin mouse by piroxicam: kinetics, strain effects and resistance to chemosuppression

Previous cancer chemoprevention studies have demonstrated that NSAIDs can be effective in suppressing the development of intestinal tumors. To further explore this issue, we performed cross-over chemoprevention studies using the drug piroxicam in the ApcMin mouse to evaluate the kinetics of NSAID-mediated tumor regression, the effects of genetic background and the incidence of resistance to chemoprevention. Starting at the time of weaning, C57BI/ 6J-ApcMin mice were fed either the control diet (AIN-93G) or AIN-93G plus 200 p.p.m. piroxicam. Tumor multiplicity was significantly reduced in ApcMin mice that were fed 200 p.p.m. piroxicam until 100 or 200 days of age (94.4 and 95.7% reduction in tumor number, respectively; P < 0.001 versus AIN-93G controls). When the administration of piroxicam was delayed until 100 days of age and the mice were killed at 200 days of age, tumor multiplicity was reduced by 96.2% (P < 0.001 versus controls). Alternatively, when the administration of piroxicam was suspended at 100 days of age and the mice were killed at 200 days of age, tumor multiplicity was reduced by 68.0% (P < 0.001 versus controls). Short-term drug treatment periods for ApcMin animals with established tumors revealed that the kinetics of piroxicam-induced tumor regression were rapid: >90% reduction in tumor multiplicity was observed after 1 week of treatment with 200 p.p.m. piroxicam. The distribution of residual tumors in piroxicam-treated mice suggests that tumors of the duodenum and colon were relatively resistant to chemosuppression. Treatment of interspecific hybrid ApcMin mice with 200 p.p.m. piroxicam revealed that there was a strain-related effect on chemosuppression, suggesting the existence of genetic elements which modulate NSAID chemosensitivity. Finally, whole-genome allelic loss studies showed that there were few unique chromosomal deletions in the NSAID-resistant tumors from F1 mice, implying that loss-of-function mutations secondary to Apc inactivation are not likely to account for the observed difference in chemoresistance.

Antiplatelet therapy. Aspirin, ticlopidine/clopidogrel, and anti-integrin agents

Aspirin is the most widely employed antithrombotic agent in use today and has a proven role in the prevention and acute management of atherosclerosis-associated arterial thrombotic events. More recently developed antiplatelet agents have been found to have specific prophylactic roles associated with percutaneous coronary intervention and other clinical settings. This article outlines pharmacologic considerations and current clinical knowledge relevant to the use of aspirin, ticlopidine, clopidogrel, and the GPIIbIIIa antagonists in the management of thrombotic disorders.

Safety profiles of leading nonsteroidal anti-inflammatory drugs

Recently introduced nonsteroidal anti-inflammatory drugs (NSAIDs) have capitalized on new formulations or unique physical and pharmacologic properties in an attempt to provide a greater margin of gastrointestinal (GI) safety. The use of enteric coatings and nonoral or pro-drug formulations have not necessarily provided the expected safety, but other properties have been identified that appear to be more promising. However, as demonstrated by oxaprozin, considered to be one of the least safe NSAIDs but one of the leading drugs on the US market, success may not be dependent on safety. In contrast, the improved tolerability of 2 other new NSAIDs, nabumetone and etodolac, has been established in clinical trials and limited postmarketing surveillance. This improved tolerability is probably associated with several pharmacologic properties that have been suggested to contribute to GI safety: (1) nonacidic pro-drug formulation; (2) lack of enterohepatic recirculation; (3) a short plasma half-life; and (4) preferential inhibition of cyclo-oxygenase-2 (COX-2). Although these factors may not improve efficacy, their incorporation into the design of drugs suggests that safer NSAIDs may be a clinical reality. However, the safety and clinical value of any new drug for the general population will be validated only through extensive postmarketing surveillance.

Future trends in the development of safer nonsteroidal anti-inflammatory drugs

Gastrointestinal (GI) adverse events, ranging from mild to life-threatening, are well-recognized sequelae to nonsteroidal anti-inflammatory drug (NSAID) use. Recent improvements in our knowledge of the mechanisms responsible for NSAID-associated gastropathy have enabled several experimental approaches to decreasing the risk of these events. Whereas such strategies as preassociation of NSAIDs to zwitterionic phospholipids to prevent NSAID-mucosal interactions and concomitant administration of trefoil peptides to stimulate mucosal defense pathways represent novel approaches, their clinical feasibility remains to be determined. Other strategies that appear more immediately promising in the reduction of NSAID-associated GI toxicity are the coupling of NSAIDs to nitric oxide (NO)-releasing compounds and the introduction of NSAIDs that are preferential or specific for cyclo-oxygenase-2 (COX-2), the isoform implicated in the inflammatory response. Clinical trials of several specific COX-2 inhibitors, as well as European clinical data for a preferential COX-2 inhibitor, meloxicam, suggest that COX-2 inhibitors provide an advantage over standard NSAIDs in terms of GI tolerability. However, as recent observations have implicated COX-2 as an integral component in the maintenance of physiologic homeostasis, careful scrutiny of both the beneficial and the deleterious effects of the selective COX-2 inhibitors is requisite before their approval and widespread use. Furthermore, based on the physiologic importance of COX-2, the preferential inhibitors may ultimately prove to represent the optimal compromise for the treatment of various arthritides.

Nonsteroidal anti-inflammatory drug-related gastrointestinal toxicity: definitions and epidemiology

Nonsteroidal anti-inflammatory drug (NSAID)-associated gastrointestinal (GI) toxicity is a broad topic encompassing symptoms as well as severe GI complications. GI bleeding and perforation are the 2 overlapping components that account for the majority of deaths and disability associated with these drugs. Abnormal gastric endoscopic profiles as well as symptoms such as heartburn, pain, and dyspepsia are common in NSAID users, but no correlation has been found between these factors and the occurrence of the more severe complications; therefore, neither symptoms nor endoscopic observations can necessarily be considered reliable predictors of future outcomes. Confounding factors can increase the risk of complications, and specific NSAIDs vary in the magnitude and type of risk attending their use. Recent studies have focused on the contribution of nonprescription NSAIDs to total complications, and combined with evidence suggesting that the risk is greatest during the first month of NSAID use, it is apparent that NSAID toxicity is an acute as well as a chronic problem.

The relation between Helicobacter pylori and nonsteroidal anti-inflammatory drugs

Both infection with Helicobacter pylori and use of nonsteroidal anti-inflammatory drugs (NSAIDs) can result in gastritis and ulcers. H. pylori has been identified as a major etiologic factor in the development of peptic ulcer disease; however, its relationship to NSAID-associated toxicity is less well characterized. Several studies have suggested that NSAID use does not increase susceptibility to H. pylori, and the converse has also been suggested, namely, that H. pylori does not exacerbate NSAID-associated injury. H. pylori itself may stimulate production of gastric prostaglandins, which may have a role in ulcer healing. More carefully controlled studies may be better able to elucidate the individual and synergistic mechanisms involved in ulceration induced by H. pylori and NSAIDs. Recent studies have suggested that elimination of H. pylori before NSAID treatment decreases ulcer occurrence. Therefore, at this time, eradication of H. pylori should be considered only in certain high-risk patients, i.e., those with a history of gastroduodenal ulcers.

Economic and gastrointestinal safety comparisons of etodolac, nabumetone, and oxaprozin from insurance claims data from patients with arthritis

This study was conducted to compare the effect of etodolac, nabumetone, and oxaprozin use on gastrointestinal (GI) safety and associated costs based on insurance claims information from practice settings. Data were obtained from a national claims database (MarketScan) for the years 1992 to 1994. The claims data of interest were for patients with arthritis who had used etodolac, nabumetone, or oxaprozin exclusively during a 9-month follow-up period (ONLY groups), or these drugs plus (PLUS groups) the other nonsteroidal anti-inflammatory drugs (NSAIDs) ibuprofen, naproxen, diclofenac, sulindac, piroxicam, ketoprofen, or indomethacin. For each group, we obtained information on the use of inpatient and outpatient services for GI-related events and the associated costs. All GI admissions were classified as NSAID-induced or possibly NSAID-induced events based on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9 CM) codes. All outpatient upper GI ulcers or bleeding episodes were also identified by specific ICD-9 CM code. There were no significant between-group demographic differences. The proportions of patients with NSAID-induced and possibly NSAID-induced GI admissions were 0.1% and 0.4% for the etodolac-ONLY, 0.3% and 1.0% for the nabumetone-ONLY, and 0.1% and 0.5% for the oxaprozin-ONLY groups, respectively (P > 0.05), and a similar pattern was observed among the PLUS groups. In outpatient settings, 3.9%, 4.2%, and 4.9% of the etodolac-, nabumetone-, and oxaprozin-ONLY patients, respectively (P > 0.05), and 6.0%, 5.3%, and 4.7% of the etodolac-, nabumetone-, and oxaprozin-PLUS patients, respectively, had at least one upper GI ulcer/bleeding claim (P > 0.05). The total health care costs for 9 months were approximately $3000 each for the etodolac-, nabumetone-, and oxaprozin-ONLY groups. Oxaprozin, nabumetone, and etodolac had similar GI-safety and associated-costs profiles based on information from practice settings. Also, in patients who used multiple NSAIDs, the groups did not differ in their GI-safety and cost profiles.

Intestinal permeability and inflammation in patients on NSAIDs

BACKGROUND

The frequency with which non-steroidal anti-inflammatory drugs (NSAIDs) increase small intestinal permeability and cause inflammation is uncertain.

AIMS

To examine small intestinal permeability and inflammation in a large number of patients on long term NSAIDs.

METHODS

Sixty eight patients receiving six different NSAIDs for over six months underwent combined absorption-permeability tests at three different test dose osmolarities (iso-, hypo-, and hyperosmolar). Two hundred and eighty six patients on 12 different NSAIDs underwent indium-111 white cell faecal excretion studies to assess the prevalence and severity of intestinal inflammation.

RESULTS

The iso- and hyperosmolar tests showed significant malabsorption of 3-0-methyl-D-glucose, D-xylose, and L-rhamnose. Intestinal permeability changes were significantly more pronounced and frequent with the hypo- and hyperosmolar as opposed to the iso-osmolar test. Sequential studies showed that four and nine patients (of 13) developed inflammation after three and six months treatment with NSAIDs, respectively. There was no significant difference (p>0.1) in the prevalence (54-72%) or severity of intestinal inflammation in the 286 patients taking the various NSAIDs apart from those on aspirin and nabumetone, these having no evidence of intestinal inflammation. There was no significant correlation between the inflammatory changes and age, sex, dose of NSAID, length of disease, or NSAID ingestion.

CONCLUSIONS

Intestinal permeability test dose composition is an important factor when assessing the effects of NSAIDs on intestinal integrity. All the conventional NSAIDs studied were equally associated with small intestinal inflammation apart from aspirin and nabumetone which seem to spare the small bowel.

Randomised controlled trial of Helicobacter pylori eradication in patients on non-steroidal anti-inflammatory drugs: HELP NSAIDs study. Helicobacter Eradication for Lesion Prevention

BACKGROUND

The effect of Helicobacter pylori in patients receiving non-steroidal anti-inflammatory drugs (NSAIDs) is unclear. We investigated the effects of H. pylori eradication in patients with current or previous peptic ulceration, dyspepsia, or both who continued to use NSAIDs.

METHODS

285 patients were randomly assigned omeprazole 20 mg, amoxycillin 1000 mg, and clarithromycin 500 mg, twice daily (n=142, H. pylori eradication treatment), or omeprazole with placebo antibiotics (n=143, controls) for 1 week. All patients received omeprazole 20 mg once daily for 3 weeks until endoscopy, and, if the ulcer was not healed, 40 mg once daily until repeat endoscopy at 8 weeks. Ulcer-free patients with mild dyspepsia continued NSAIDs but not antiulcer treatment. We investigated ulcers with endoscopy at 1, 3, and 6 months and with carbon-13-labelled urea breath test at 3 months.

FINDINGS

The estimated probability of being ulcer-free at 6 months was 0.56 (95% CI 0.47-0.65) on eradication treatment and 0.53 (0.44-0.62) on on control treatment (p=0.80). Time to treatment failure did not differ between groups for ulcers or dyspepsia alone, per-protocol analysis, or final H. pylori status. 66% (58-74) of the eradication group compared with 14% (8-20) of the control group had a final negative H. pylori result (p<0.001). Fewer baseline gastric ulcers healed among eradication-treatment patients than among controls (72 vs 100% at 8 weeks, p=0.006).

INTERPRETATION

H. pylori eradication in long-term users of NSAIDs with past or current peptic ulcer or troublesome dyspepsia led to impaired healing of gastric ulcers and did not affect the rate of peptic ulcers or dyspepsia over 6 months.

NSAIDs and faecal blood loss in elderly patients with osteoarthritis: is plasma half-life relevant?

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) vary in their degree of gastrointestinal (GI) toxicity. NSAIDs with longer half-lives are of particular concern as they may be more toxic in the elderly.

AIM

To compare the GI toxicity, by measurement of faecal blood loss, of short, intermediate and long half-life NSAID treatments compared with control in elderly patients with osteoarthritis.

METHODS

Twenty-three patients, mean age 69 years, with osteoarthritis requiring NSAID treatment, received treatment with diclofenac 100 mg/day, naproxen 750 mg/day and piroxicam 20 mg/day, representing a short, medium and long half-life NSAID respectively, in a double-blind, randomised, three way, cross-over block design. In each case, a three week washout control phase was followed by active treatment phases of two weeks each with three week washout between treatment phases.

RESULTS

Faecal blood loss, collected over 72 hours at the end of each treatment phase, was measured by 51Cr-labelled erythrocyte method. Comparison was made of mean 24 hour faecal blood loss with each treatment compared with control using repeated measures analysis of variance. Eighteen patients completed all phases of the study. Three patients were withdrawn due to GI bleeding; two during diclofenac treatment and one during treatment with piroxicam. Mean 24 hour faecal blood loss with diclofenac (0.53 mL +/- 0.21) was not significantly different from control (0.28 mL +/- 0.06), whereas it was significantly increased with naproxen (2.76 mL +/- 2.22) and piroxicam (1.16 mL +/- 0.62), p = 0.0013.

CONCLUSION

A short half-life NSAID was associated with lower GI toxicity than a medium and long half-life NSAID, as measured by faecal blood loss.

Gastrointestinal tolerability of meloxicam and piroxicam: a double-blind placebo-controlled study

AIMS

The aim of the study was to compare the effects of meloxicam and piroxicam on the gastroduodenal mucosa in healthy adults.

METHODS

Forty-four healthy volunteers were given a 28 day course of either meloxicam 15 mg, piroxicam 20 mg or placebo. Damage to the oesophageal, gastric and duodenal mucosa was assessed, mucosal blood flow (MBF) measured at endoscopy and biopsies taken for prostaglandin content and microscopic assessment of damage before NSAID administration and during days 1, 7 and 28 of continued intake.

RESULTS

Maximal macroscopic gastric mucosal damage (median grade+IQR) occurred within 24 h of piroxicam administration, the damage score increasing from 0 to 2.5 (0-3) (P=0.02) at day 1 before falling to 2.0 (0-2) at day 7 and 0 (0-1) at day 28 with resolution of damage observed in six out of the seven subjects who sustained acute injury. No significant macroscopic gastric damage occurred in either of the two other groups although some minor damage was observed in seven subjects taking placebo and five taking meloxicam. There was a trend towards piroxicam causing more acute gastric damage than meloxicam (P=0.06). Baseline antral, body and duodenal MBF were similar in all three groups. No significant changes occurred in any of the groups on any of the visits. There were also no changes in gastric mucosal prostaglandin content in any group.

CONCLUSIONS

These observations suggest that meloxicam causes little acute damage to the upper gastrointestinal tract and piroxicam causes some acute gastric injury but such damage resolves in most subjects by 28 days.

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.

Cyclooxygenase-1 and cyclooxygenase-2 selectivity of widely used nonsteroidal anti-inflammatory drugs

PURPOSE

Both isoforms of cyclo-oxygenase, COX-1 and COX-2, are inhibited to varying degrees by all of the available nonsteroidal anti-inflammatory drugs (NSAIDs). Because inhibition of COX-1 by NSAIDs is linked to gastrointestinal ulcer formation, those drugs that selectively inhibit COX-2 may have less gastrointestinal toxicity. We measured the extent to which NSAIDs and other anti-inflammatory or analgesic drugs inhibit COX-1 and COX-2 in humans.

SUBJECTS AND METHODS

Aliquots of whole blood from 16 healthy volunteers were incubated ex vivo with 25 antiinflammatory or analgesic drugs at six concentrations ranging from 0 (control) to 100 microM (n = 5 for each). Blood was assayed for serum-generated thromboxane B2 synthesis (COX-1 assay) and for lipopolysaccharide-stimulated prostaglandin E2 synthesis (COX-2 assay). In addition, gastric biopsies from the same volunteers were incubated with each drug ex vivo and mucosal prostaglandin E2 synthesis measured.

RESULTS

Inhibitory potency and selectivity of NSAIDs for COX-1 and COX-2 activity in blood varied greatly. Some NSAIDs (eg, flurbiprofen, ketoprofen) were COX-1 selective, some (eg, ibuprofen, naproxen) were essentially nonselective, while others (eg, diclofenac, mefenamic acid) were COX-2 selective. Inhibitory effects of NSAIDs on gastric prostaglandin E2 synthesis correlated with COX-1 inhibitory potency in blood (P < 0.001) and with COX-1 selectivity (P < 0.01), but not with COX-2 inhibitory potency. Even COX-2 "selective" NSAIDs still had sufficient COX-1 activity to cause potent inhibitory effects on gastric prostaglandin E2 synthesis at concentrations achieved in vivo.

CONCLUSION

No currently marketed NSAID, even those that are COX-2 selective, spare gastric COX activity at therapeutic concentrations. Thus, all NSAIDs should be used cautiously until safer agents are developed.

Comparison of cyclooxygenase-1 and -2 inhibitory activities of various nonsteroidal anti-inflammatory drugs using human platelets and synovial cells

Recent studies have shown that cyclooxygenase exists in two isozyme forms. Since differences in the pharmacological profiles of nonsteroidal anti-inflammatory drugs (NSAIDs) might be accounted for by varying degrees of selectivity for these isozymes, cyclooxygenase-1 and -2, the relative potency of various NSAIDs in inhibiting their activities was examined in intact human cells. We used human platelets cyclooxygenase-1 and interleukin-1beta-stimulated human synovial cell cyclooxygenase-2 for measuring cyclooxygenase selectivity. The presence of the enzymes was confirmed by immunoblotting and immunoprecipitation analysis, and by the reverse transcriptase-polymerase chain reaction. Mean IC50 values (microM) for human platelet cyclooxygenase-1 and interleukin-1beta-stimulated human synovial cell cyclooxygenase-2 and cyclooxygenase-1/-2 IC50 ratio of various NSAIDs were as follows: aspirin, 3.2, 26, 0.12; diclofenac, 0.037, 0.00097, 38; etodolac, 122, 0.68, 179; ibuprofen, 3.0, 3.5, 0.86; indomethacin, 0.013, 0.044, 0.30; loxoprofen (active metabolite), 0.38, 0.12, 3.2; NS-398, 12, 0.0095, 1263; oxaprozin, 2.2, 36, 0.061; zaltoprofen, 1.3, 0.34, 3.8; respectively. Our bioassay system employing intact human cells to assess the cyclooxygenase selectivity of NSAIDs may provide clinically useful information.

Are altered pharmacokinetics of non-steroidal anti-inflammatory drugs (NSAIDs) a risk factor for gastrointestinal bleeding?

AIMS

We hypothesised that pharmacokinetic factors might go some way to explaining the risk of major gastrointestinal haemorrhage with non-steroidal anti-inflammatory drugs (NSAIDs), with bleeders exhibiting a reduced clearance of NSAIDs compared with non-bleeders and set out to investigate this.

METHODS

Fifty patients presenting to hospital with acute gastrointestinal bleeding while taking piroxicam, indomethacin, diclofenac or naproxen and age, sex, musculoskeletal disease and drug matched community dwelling controls, up to two for each index case, who had not bled were recruited. Clinical details including duration of therapy were recorded. Bleeders discontinued the implicated NSAID at presentation, controls at least five half-lives before the study. Bleeders were contacted by letter 1 month after discharge and invited to take part and were studied after a median delay of 5 months. Subjects received an oral dose of their respective NSAID and venous blood was sampled, over a period determined by the half-life of the NSAID. Plasma concentrations were determined by high performance liquid chromatography.

RESULTS

The median length of treatment for the index patients was 1 year (range 2 weeks--28 years) and for the control patients 2 years (1 month--25 years), P<0.0005. There were no significant differences in peak plasma concentration, time to peak plasma concentration or area under the plasma concentration-time curve between bleeders or controls for any of the NSAIDs studied, apart from piroxicam Cmax being lower in bleeders at 2.07 mg l(-1) than in controls at 3.21 mg l(-1), mean difference (95% CI) -1.14 (-1.83 - -0.48), P<0.005.

CONCLUSIONS

The data failed to support the hypothesis that reduced clearance of NSAIDs, which results in higher plasma concentrations, is a risk factor for acute gastrointestinal haemorrhage.

Epidemiology of nonsteroidal anti-inflammatory drug-associated gastrointestinal injury

Nonaspirin, nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used drugs in many countries. Use of the majority of NSAIDs increases with age, primarily for symptoms associated with osteoarthritis and other chronic musculoskeletal conditions. Population-based studies have shown that, on any given day, 10-20% of elderly people (> or = 65 years old) have a current or recent NSAID prescription. Over a 6-month period in Alberta, Canada, 27% of elderly people were prescribed NSAIDs. Furthermore, in Tennessee (USA), 40% of elderly people received at least one NSAID prescription annually, and 6% had NSAID prescriptions for > 75% of the year. NSAIDs cause a wide variety of side-effects. The most clinically important side-effects are upper gastrointestinal tract dyspepsia, peptic ulceration, hemorrhage, and perforation, leading to death in some patients. Gastrointestinal side-effects are common; the most common NSAID-associated side-effect is epigastric pain/indigestion. Gastrointestinal side-effects are also a frequent reason both for withdrawal of NSAIDs and for co-treatment with another drug. Indeed, in two population-based studies of people aged > or = 65 years, the use of agents to prevent peptic ulcers or relieve dyspepsia was nearly twice as common in regular NSAID users (20-26%) than in non-NSAID users (11%). In Alberta, Canada, it has been estimated that NSAID use accounts for 28% of all prescriptions for anti-ulcer drugs in people aged at least 65 years. Many studies have now shown that NSAIDs increase the risk of peptic ulcer complications by 3-5-fold, and in several different populations it has been estimated that 15-35% of all peptic ulcer complications are due to NSAIDs. In the United States alone, there are an estimated 41,000 hospitalizations and 3,300 deaths each year among the elderly that are associated with NSAIDs. Factors that increase the risk of serious peptic ulcer disease include older age, history of peptic ulcer disease, gastrointestinal hemorrhage, dyspepsia, and/or previous NSAID intolerance, as well as several measures of poor health.

Variability in risk of gastrointestinal complications with different nonsteroidal anti-inflammatory drugs

Exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) is known to increase substantially the risk of upper gastrointestinal bleeding and/or perforation. A meta-analysis of the available epidemiologic studies has shown that there are wide differences between individual drugs in the risk of inducing gastrointestinal complications. Of the NSAIDs in common use, ibuprofen and diclofenac were found to be associated with the lowest relative risk; indomethacin, naproxen, sulindac, and aspirin were associated with intermediate risk; and azapropazone, tolmetin, ketoprofen, and piroxicam were associated with higher risk. Some of these apparent differences in toxicity may, however, be dose related. The low risk of gastrointestinal complications associated with ibuprofen appears to be attributable to the low doses that are prescribed routinely in clinical practice. Higher doses of ibuprofen were associated with relative risks similar to those of naproxen and indomethacin. Thus, as first-line treatment, patients should be prescribed the lowest effective dose of an NSAID that appears to be associated with a comparatively low risk. This should substantially reduce the morbidity and mortality from serious gastrointestinal complications that are associated with the use of these drugs.

Omeprazole compared with misoprostol for ulcers associated with nonsteroidal antiinflammatory drugs. Omeprazole versus Misoprostol for NSAID-induced Ulcer Management (OMNIUM) Study Group

BACKGROUND

Misoprostol is effective for ulcers associated with the use of nonsteroidal antiinflammatory drugs (NSAIDs) but is often poorly tolerated because of diarrhea and abdominal pain. We compared the efficacy of omeprazole and misoprostol in healing and preventing ulcers associated with NSAIDs.

METHODS

In a double-blind study, we randomly assigned 935 patients who required continuous NSAID therapy and who had ulcers or more than 10 erosions in the stomach or duodenum (or both) to receive 20 mg or 40 mg of omeprazole orally in the morning or 200 microg of misoprostol orally four times daily. Patients were treated for four weeks or, in the absence of healing, eight weeks. Treatment success was defined as the absence of ulcers and the presence of fewer than five erosions at each site and not more than mild dyspepsia. We then randomly reassigned 732 patients in whom treatment was successful to maintenance therapy with 20 mg of omeprazole daily, 200 microg of misoprostol twice daily, or placebo for six months.

RESULTS

At eight weeks, treatment was successful in 76 percent of the patients given 20 mg of omeprazole (233 of 308), 75 percent of those given 40 mg of omeprazole (237 of 315), and 71 percent of those given misoprostol (212 of 298). The rates of gastric-ulcer healing were significantly higher with 20 mg of omeprazole (but not 40 mg of omeprazole) than with misoprostol. Healing rates among patients with duodenal ulcers were higher with either dose of omeprazole than with misoprostol, whereas healing rates among patients with erosions alone were higher with misoprostol. More patients remained in remission during maintenance treatment with omeprazole (61 percent) than with misoprostol (48 percent, P=0.001) and with either drug than with placebo (27 percent, P<0.001). There were more adverse events during the healing phase in the misoprostol group than in the groups given 20 mg and 40 mg of omeprazole (59 percent, 48 percent, and 46 percent, respectively).

CONCLUSIONS

The overall rates of successful treatment of ulcers, erosions, and symptoms associated with NSAIDs were similar for the two doses of omeprazole and misoprostol. Maintenance therapy with omeprazole was associated with a lower rate of relapse than misoprostol. Omeprazole was better tolerated than misoprostol.

Tenoxicam, a non-steroid anti-inflammatory drug, is unable to increase the response rate in patients with chronic hepatitis C treated by alpha interferon

The purpose of this study is to compare a combination of interferon (IFN)-alpha2a (Roferon) + Tenoxicam with IFN-alpha2a alone in the treatment of chronic hepatitis C. This prospective, randomized double-blind study included 149 patients, all of whom were diagnosed with active chronic hepatitis C but non-cirrhotic (ALT > or = 1.5 upper limit of normal, anti-hepatitis C virus (HCV) positive by enzyme-linked immunosorbant assay2 and RIBA3). The patients were randomized in two groups, as follows: G1 (n = 76): IFNalpha2a 3 million units times per week during 6 months + placebo; and G2 (n = 73): IFNalpha2a 3 million units three times per week + Tenoxicam (20 mg/day) during 6 months. Alanine aminotransferase (ALT) and HCV RNA were determined before and at months 6 and 12 of treatment. 2'5' oligoadenylate synthetase activity (2'5' AS) was dosed in mononuclear cells before and at 3-month treatment intervals in 28 patients. Liver biopsy was performed before and 6 months after the end of therapy. Parameters were similar before therapy for both groups. Biochemical and virological responses were similar for both groups at month 6 (49.3% vs. 42.9% and 43.3% vs. 38.3%, respectively) and month 12 (28.3% vs. 23.8% and 17.2% vs. 17.5%, respectively). HCV RNA level significantly decreased in both groups at month 6, with no difference whatever the therapy; however, the HCV RNA level returned to initial values at month 12 and was the only significant prognostic factor of a sustained response. No peak of 2'5' AS activity was observed during treatment in patients with dual therapy. A histological improvement was also noted in both groups without difference, regardless of therapy. The percentage of adverse events was identical for both groups. Paracetamol intake, assessed in 80 patients, was 49.1 g per 6 months in the G1 group and 22.5 g per 6 months in the G2 group (not significant). In conclusion, the non-steroid anti-inflammatory drug, Tenoxicam, does not increase IFNalpha efficacy in the treatment of chronic hepatitis C. This combination is well tolerated and partially lowers Paracetamol intake, but not preexisting alpha-IFN adverse events.

Clinical economics review: gastrointestinal complications of non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely used symptomatic remedies for rheumatic disorders. Their major side-effects involve the gastrointestinal tract and, while the stomach is often the prime focus of adverse reactions, the whole gut may be involved. A number of strategies have been used to reduce both the incidence of side-effects and their economic consequences. Decreased NSAID use can be achieved both by rational prescribing and by active promotion of other, usually non-pharmacological, methods of controlling symptoms. Prescribing NSAIDs based on their cost assumes all have equal efficacy and side-effects, which is demonstrably untrue. Picking the least toxic NSAID is more logical. Most of the larger studies and meta-analyses available concentrate on older NSAIDs and risk overlooking the advantages of newer preparations which have been shown to be cost beneficial by more comprehensive economic analyses. Misoprostol prophylaxis has been the subject of a number of economic evaluations which, until recently, were based on extrapolations rather than clinical data. There are now good clinical data available which show a small but significant reduction in major side-effects at the expense of an increase in minor but unpleasant ones. Proton pump inhibitors appear to offer the same degree of gastroprotection as misoprostol, with the additional benefit of symptom relief. Economic data regarding the costs and benefits of prophylaxis with proton pump inhibitors are not yet available. There is still a need for a more comprehensive evaluation of the benefits of NSAIDs in different clinical situations to balance against the costs of adverse reactions.

Pharmacotherapy and osteoarthritis

Therapy for osteoarthritis (OA) is aimed at relieving symptoms and at maximizing function. Therapies can be considered as either symptom modifying OA drugs (SMOADs) or as disease modifying OA drugs (DMOADs). Currently available agents fall into the category of SMOADs. Analgesic medications, particularly paracetamol and capsaicin, have proven efficacy in OA and are recommended first line therapies. Non-steroidal anti-inflammatory drugs (NSAIDs) do appear to provide extra symptomatic benefit for some patients but have greater toxicity. Newer generation NSAIDs may have safety advantages which remain to be confirmed in practice. Further therapies are being developed which aim to prevent cartilage damage and/or aid cartilage restoration, but these DMOADs remain in the experimental stage.

Effects of ibuprofen enantiomers and its coenzyme A thioesters on human prostaglandin endoperoxide synthases

1. Ibuprofen enantiomers and their respective coenzyme A thioesters were tested in human platelets and blood monocytes to determine their selectivity and potency as inhibitors of cyclo-oxygenase activity of prostaglandin endoperoxide synthase-1 (PGHS-1) and PGHS-2. 2. Human blood from volunteers was drawn and allowed to clot at 37 degrees C for 1 h in the presence of increasing concentrations of the test compounds (R-ibuprofen, S-ibuprofen, R-ibuprofenoyl-CoA, S-ibuprofenoyl-CoA, NS-398). Immunoreactive (ir) thromboxane B2 (TXB2) concentrations in serum were determined by a specific EIA assay as an index of the cyclo-oxygenase activity of platelet PGHS-1. 3. Heparin-treated blood from the same donors was incubated at 37 degrees C for 24 h with the same concentrations of the test compounds in the presence of lipopolysaccharide (LPS, 10 microg ml[-1]). The contribution of PGHS-1 was suppressed by pretreatment of the volunteers with aspirin (500 mg; 48 h before venepuncture). As a measure of LPS induced PGHS-2 activity immunoreactive prostaglandin E2 (irPGE2) plasma concentrations were determined by a specific EIA assay. 4. S-ibuprofen inhibited the activity of PGHS-1 (IC50 2.1 microM) and PGHS-2 (IC50 1.6 microM) equally. R-ibuprofen inhibited PGHS-1 (IC50 34.9) less potently than S-ibuprofen and showed no inhibition of PGHS-2 up to 250 microM. By contrast R-ibuprofenoyl-CoA thioester inhibited PGE2 production from LPS-stimulated monocytes almost two orders of magnitude more potently than the generation of TXB2 (IC50 5.6 vs 219 microM). 5. Western blotting of PGHS-2 after LPS induction of blood monocytes showed a concentration-dependent inhibition of PGHS-2 protein expression by ibuprofenoyl-CoA thioesters. 6. These data confirm that S-ibuprofen represents the active entity in the racemate with respect to cyclo-oxygenase activity. More importantly the data suggest a contribution of the R-enantiomer to therapeutic effects not only by chiral inversion to S-ibuprofen but also via inhibition of induction of PGHS-2 mediated by R-ibuprofenoyl-CoA thioester. 7. The data may explain why racemic ibuprofen is ranked as one of the safest non-steroidal anti-inflammatory drugs (NSAIDs) so far determined in epidemiological studies.

Copper-salicylate gel for pain relief in osteoarthritis: a randomised controlled trial

OBJECTIVE

To assess the efficacy and safety of a copper-salicylate gel in osteoarthritis of the hip and knee.

DESIGN

Randomised, double-blind, placebo-controlled study.

SETTING

Rheumatology Clinic of St Vincent's Hospital, Sydney, New South Wales (a tertiary referral hospital), June 1993 to October 1994.

PATIENTS

116 patients with pain associated with osteoarthritis of the hip and/or knee (diagnosed by criteria of the European League against Rheumatism), drawn from patients attending the Clinic or self-referred after newspaper advertisements.

INTERVENTION

Copper-salicylate or placebo gel (1.5 g) applied twice daily to the forearm for four weeks.

OUTCOME MEASURES

Self-assessment of pain before the trial and after two and four weeks of treatment; patient and investigator assessments of efficacy; additional analgesia required; adverse reactions; and withdrawal rates.

RESULTS

Pain scores at rest and on movement decreased in both the copper-salicylate and placebo groups by 13%-20%. There was no significant difference between the two groups for decrease in pain score, patient and investigator efficacy ratings, number of patients requiring paracetamol for extra analgesia (active, 77%; placebo, 71%) and average dose of paracetamol (active, 555 mg/day; placebo, 600 mg/day). Significantly more patients in the copper-salicylate group reported adverse reactions (83% versus 52% of the placebo group), most commonly skin reactions, and withdrew from the trial because of these reactions (17% versus 1.7% of the placebo group).

CONCLUSION

Copper-salicylate gel applied to the forearm was no better than placebo gel as pain relief for patients with osteoarthritis of the hip or knee, but produced significantly more skin rashes.