[Medicine-caused itch, wounds and bullous skin in three patients with pseudoporphyria]

Pseudoporphyria cutanea tarda is a well described bullous skin disorder which resembles porphyria cutanea tarda. However, the levels of porphyrins in plasma, urine and faeces are normal. We present three cases of patients with classical symptoms of pseudoporphyria. Two of the patients developed pseudoporphyria after the combination of intensive sunbathing and medications well known to cause pseudoporphyria. The third case received haemodialysis and furosemide.

Treatment of mild to moderate acne with a fixed combination of hydroxypinacolone retinoate, retinol glycospheres and papain glycospheres

AIM

A fixed combination of 0.1% hydroxypinacolone retinoate (synthetic esther of 9-cis-retinoic acid), 1% retinol in glycospheres and 2% papain in glycospheres in aqueous gel has been recently introduced into the Italian market in order to reduce the incidence and severity of irritant contact dermatitis caused by topical retinoids, without compromising their efficacy. Primary objectives of this sponsor-free, pilot, open, multicenter study were to evaluate the efficacy and tolerability of this gel in patients with comedonal-papular, mild to moderate acne of the face.

METHODS

Ninety-eight Caucasian patients (28 males and 70 females), with an age ranging from 15 to 40 years, were treated with the gel once daily for 12 weeks. Acne severity and treatment efficacy were evaluated by means of the Global Acne Grading System (GAGS) and lesions count.

RESULTS

Ninety-four patients were considered evaluable. A 41% mean reduction in the GAGS score was observed; a 40.8% mean reduction of total lesions was recorded; 15.3% of patients experienced mild to moderate local side effects (dryness, peeling, erythema, burning). No patients stopped the treatment because of these side effects.

CONCLUSION

This study, based on a high number of evaluable patients, demonstrates that this fixed combination is an effective and safe option for the treatment of comedonal-papular, mild to moderate acne of the face. A controlled clinical study is necessary to confirm these data.

Tolerability to nabumetone and meloxicam in patients with nonsteroidal anti-inflammatory drug intolerance

BACKGROUND

Because nonsteroidal anti-inflammatory drug (NSAID) intolerance depends on COX-1 inhibition, preferential or selective COX-2 inhibitors have been thought to be well tolerated by these patients.

OBJECTIVE

The aim of this study is to evaluate tolerability to nabumetone and meloxicam in patients with NSAID intolerance.

METHODS

Seventy patients intolerant to NSAIDs were selected. Thirty subjects were patients with asthma with respiratory (rhinitis-asthma) intolerance to NSAIDs (group A); 40 patients (group B) had cutaneous-mucous (urticaria-angioedema) NSAID intolerance. Diagnosis was based on clinical histories in all patients, and it was confirmed by positive single-blind placebo-controlled oral challenge test in 36 patients. After written informed consent, a single-blind placebo-controlled oral challenge test with nabumetone in all patients (2 g except for 11 patients who reached 1 g) and meloxicam (15 mg) in 51 patients was performed.

RESULTS

Of the total selected, 94.3% tolerated 1 g nabumetone. In those who reached the 2-g dose, the tolerability was 83.6%. With respect to meloxicam, 96.1% of patients, tolerated 15 mg. No significant difference in nabumetone and meloxicam tolerability was observed between groups A and B.

CONCLUSION

The results of this study confirm a high percentage of tolerability to the maximum therapeutic dosage of nabumetone and meloxicam in patients with NSAID intolerance, both in those with cutaneous/mucous manifestations and in those with respiratory disease.

CLINICAL IMPLICATIONS

Nabumetone and meloxicam are safe alternatives in NSAID-intolerant patients.

Severe immediate reaction to nabumetone

Nabumetone is a nonsteroidal antiinflammatory (NSAID) prodrug that inhibits cyclooxygenase-2. It has been recommended as a safe alternative in most patients with hypersensitivity reactions to NSAIDs. Systemic reactions caused by nabumetone are not frequent. We report 2 cases of immediate systemic reactions due to nabumetone. The first case involved a 68-year-old woman who developed immediate generalized pruritus, erythema, morbilliform eruption, swollen tongue sensation, diarrhea, and hypotension after the ingestion of a single dose of nabumetone. In the second case, a 77-year-old woman developed generalized pruritus, palm erythema, colic abdominal pain, diarrhea, dizziness, tightness of the chest, dyspnea, and hypotension immediately after oral intake of nabumetone. Both patients had previously tolerated this drug. Since these episodes, they have avoided nabumetone. Skin prick tests with nabumetone (10 and 100 mg/mL) were negative. Oral challenge tests with other NSAIDs, even of the same group as nabumetone, were negative in both patients. The mechanisms responsible for the reaction were not established.

Prevalence and mechanism of nonsteroidal anti-inflammatory drug-induced clinical relapse in patients with inflammatory bowel disease

BACKGROUND & AIMS

It has been variably suggested that nonselective NSAIDs and cyclooxygenase (COX)-2 selective inhibitors aggravate or ameliorate clinical disease activity in patients with inflammatory bowel disease. We assessed the effect of these drugs in patients with inflammatory bowel disease (n = 209) and the possible mechanisms.

METHODS

First, patients with quiescent Crohn's disease and ulcerative colitis received the non-NSAID analgesic acetaminophen (n = 26) and the conventional NSAIDs naproxen (n = 32), diclofenac (n = 29), and indomethacin (n = 22) for 4 weeks. The Harvey-Bradshaw index was used to define relapse. Second, to assess the mechanism of relapse, intestinal inflammation was quantitated (fecal calprotectin) before and during treatment (20 patients/group) with acetaminophen, naproxen (topical effect, COX-1 and -2 inhibitor), nabumetone (COX-1 and -2 inhibitor), nimesulide (selective COX-2 inhibitor), and low-dose aspirin (selective COX-1 inhibition).

RESULTS

Nonselective NSAIDs were associated with a 17%-28% relapse rate within 9 days of ingestion. No patient had an early relapse on acetaminophen, nimesulide, or aspirin, whereas those on naproxen and nabumetone (20%) experienced relapse. These clinical relapses were associated with escalating intestinal inflammatory activity.

CONCLUSIONS

NSAID ingestion is associated with frequent and early clinical relapse of quiescent inflammatory bowel disease, and the mechanism appears to be due to dual inhibition of the COX enzymes. Selective COX-2 inhibition with nimesulide and COX-1 inhibition with low-dose aspirin appear to be well-tolerated in the short-term.

Risk of hospitalization with peptic ulcer disease or gastrointestinal hemorrhage associated with nabumetone, Arthrotec, diclofenac, and naproxen in a population based cohort study

OBJECTIVE

To identify the unbiased differences in the risk of hospitalization with peptic ulcer disease (PUD) or gastrointestinal (GI) hemorrhage among populations using 4 nonsteroidal antiinflammatory drugs (NSAID): nabumetone, Arthrotec, diclofenac plus a cytoprotective agent dispensed separately (diclo+coRx), and naproxen.

METHODS

A population based historical cohort study using linked data from provincial healthcare databases. The population of the province of Saskatchewan, Canada, entitled to drug plan benefits in 1995 was eligible (roughly 91% of 1 million people). Participants were identified if they filled a prescription for one of the 4 study NSAID (18,424 individuals). They were then followed for 6 months to determine outcomes. Logistic regression was used to produce estimates of the risk of admission to hospital with a primary diagnosis of PUD or GI hemorrhage associated with the study drugs unbiased by known confounders.

RESULTS

Compared to Arthrotec the adjusted odds of hospitalization for PUD for participants taking nabumetone was 2.6 (95% CI 1.0-6.6), diclo+coRx 6.8 (95% CI 3.5-13.4), and naproxen 7.9 (95% CI 3.9-15.9). Compared to nabumetone the adjusted odds of hospitalization for PUD for participants taking diclo+coRx was 2.7 (95% CI 1.2-6.0) and naproxen 3.1 (95% CI 1.3-7.1). No significant differences were noted in terms of admissions for GI hemorrhage.

CONCLUSION

Participants taking nabumetone and Arthrotec had significantly lower risk of hospitalization for PUD than those taking the other study drugs. Arthrotec was superior to nabumetone in a head to head comparison and especially when compared with the diclo+coRx and naproxen groups. No short term differences were seen in the rates of admission for GI hemorrhage. It appears that inherent gastroprotective strategies with Arthrotec and to a lesser extent with nabumetone do translate into decreased serious GI side effects at the population level in the short term.

Low direct cytotoxicity of nabumetone on gastric mucosal cells

Prodrugs of non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for clinical purposes because they are not harmful to the gastrointestinal mucosa. We recently showed that NSAIDs have direct cytotoxicity in NSAID-induced gastric lesions. We show here that under conditions where the NSAIDs indomethacin and celecoxib clearly induce cell death, an NSAID prodrug, nabumetone, and its active metabolite 6-methoxy-2-naphthylacetic acid (6MNA), did not have such effects. Moreover, nabumetone and 6MNA exhibited much lower membrane permeabilizing activities than did indomethacin and celecoxib. We recently reported that when an orally administered NSAID was used in combination with a low dose of intravenously administered indomethacin, the severity of gastric lesions produced in rats depended on the cytotoxicity of the orally administered NSAID. Using a similar protocol, we show here that gastric lesions were produced when the orally administered NSAID was celecoxib, but not when nabumetone was used. We thus propose that the low direct cytotoxicity of nabumetone observed in vitro is maintained in vivo, and that the use of nabumetone does not harm the gastric mucosa.

Evaluation of Current Biological Exposure Index for Occupational N, N-dimethylformamide Exposure From Synthetic Leather Workers

The aim of this study was (1) to investigate the correlation between external exposure to N, N-dimethylformamide (DMF) and urinary excretion of DMF and N-methylformamide; (2) to assess whether the correspondence between the current occupational exposure limit setting and recommended urinary biological exposure index is substantial; and (3) to evaluate whether coexposure to toluene, methyl ethyl ketone, and ethyl acetate has an effect on urinary excretion of DMF and N-methylformamide (NMF). Urinary DMF and NMF were significantly correlated (P < 0.01) with one another and also significantly correlated with airborne DMF (P < 0.01) over the range of 1.55 to 152.8 mg/m. Urinary DMF can be considered a complementary marker for short-term exposure. Urinary concentration of NMF and DMF, corresponding to the 8-hour exposure to airborne DMF at 30 mg/m, was estimated to 38.4 mg/L or 39.4 mg/g creatinine for NMF and to 0.92 mg/L or 0.96 mg/g creatinine for DMF.

Adverse effect of drug-induced emotional problems on work and daily activities. A principal component as an independent predictor of ADRs in Shanghai patients with osteoarthropathy taking nabumetone

OBJECTIVE

To discover principal components among assessed items from the WHO-SF36 survey by principal component analysis (PCA) and then to establish the relationship between the candidate principal component and the incidence of ADRs induced by nabumetone in Shanghai osteoarthropathy patients.

METHOD

A total of 145 patients were interviewed using the WHO-SF36 questionnaire for quality of life (QOL) assessment before the administration of nabumetone. The sub-items of the questionnaire were analyzed using PCA and several comprehensive variables were established. Relationships between these newly formed variables and the overall incidence of adverse drug reactions (ADRs) caused by nabumetone were evaluated using univariate and multivariate analyses.

RESULTS

Several principal components were identified and their linear parameters were estimated using PCA. Through univariate analysis, only 1 principal component--"adverse effect on work and daily activities as a result of emotional problems"--was found related to the incidence of ADRs. The odds ratio (OR) was 1.28 with 95% confidence intervals (CI) of 1.11 and 1.48, p = 0.0384. This result was validated using a multivariate logistic analysis performed on all the alternative candidate covariates, including family income, a history of ADRs on NSAIDs, the course of the disease, level of education, control of stress, coffee consumption and consumption of salty food. The covariate information was taken from other parts of the clinical report form (CRF) used in this research. The analysis proved that the principal component, adverse effect on work and daily activities as a result of emotional problems, was an independent factor related to the overall incidence of ADRs. The odds ratio (OR) from the logistic analysis was 1.34, with 95% confidence intervals (CI) of 1.16 and 1.55, p = 0.0309.

CONCLUSIONS

The principal component identified can be applied to overcome some limitations in the WHO-SF36 questionnaire such as high correlation between variables, information overlaps and weak representation of variables and the statistical data analysis of QOL can therefore be made more effective. The study shows that the principal component "adverse effect on work and daily activities as a result of emotional problems" is an independent predictor of the overall incidence of ADRs induced by nabumetone.

A population based historical cohort study of the mortality associated with nabumetone, Arthrotec, diclofenac, and naproxen

OBJECTIVE

To identify the unbiased differences in all cause mortality among populations using 4 non-steroidal antiinflammatory drugs (NSAID): nabumetone, Arthrotec, diclofenac plus a cytoprotective agent dispensed separately (diclofenac+), and naproxen.

METHODS

We performed a population based historical cohort study using linked data from several provincial health care databases. Logistic regression was used to produce estimates of the mortality associated with the study drugs unbiased by known confounders. The entire population of the province of Saskatchewan, Canada entitled to drug plan benefits in 1995 was eligible (approximately 91% of 1 million people). Participants were identified if they filled a prescription for one of the 4 study NSAID (18,424 individuals). They were then followed forward in time for 6 months to determine all cause mortality.

RESULTS

Compared to nabumetone, the adjusted odds of death for participants taking Arthrotec was 1.4 (95% confidence interval, CI: 0.9-2.1), for diclofenac+ 2.0 (1.3-3.1), and naproxen 3.0 (1.9-4.6).

CONCLUSION

The multivariate analysis showed patients taking nabumetone and Arthrotec had significantly lower mortality than those taking other study drugs. Nabumetone had 1/3 to 1/5 the mortality associated with the diclofenac+ and naproxen groups. It appears that inherent gastroprotective strategies in the study NSAID may translate into decreased mortality at the population level.

[Orthokin as new therapeutic option for orthopedic diseases]

The synthesis and introduction of interleukin-1 receptor antagonists established a promising strategy in the treatment of inflammatory diseases. This kind of therapy is claimed now to be available for osteoarthritis and other orthopedic disorders also. In the case of "orthokin", the interleukin-1 receptor antagonist is produced by stimulation of own blood-cells. It is not possible, to evaluate the practicability of this therapeutic approach because there are no published experimental data. We also found no results of clinical studies, which would allow an estimation of the effectiveness and the risks of this method. Therefore treatment with "orthokin" cannot be recommended at present.

Risk factors of adverse drug reaction from non-steroidal anti-inflammatory drugs in Shanghai patients with arthropathy

AIM

The study was to screen the possible risk factors of adverse drug reaction (ADR) induced by non-steroidal anti-inflammatory drugs (NSAIDs) in Shanghai patients with arthropathy.

METHODS

The subjects were randomly selected from a database of outpatients with arthropathy from 9 main hospitals in Shanghai. A door to door retrospective epidemiological survey was used to collect demographic information about the patients, both individual and familial. This included data on their medical histories, lifestyle and dietary habits, history of smoking and alcohol consumption, history of drug therapy, quality of life (QOL) prior to NSAIDs intake, history of NSAIDs therapy and its ADR events, etc. Descriptive statistical methods and univariate analysis were also used to identify possible risk factors for ADRs induced by NSAIDs.

RESULTS

Of the 1002 patients surveyed, the average length of NSAIDs intake was 2 years. ADR incidence from different NSAIDs was high, in a range from 46.7 %-66.2 %. In general, the candidate risk factors for ADRs were different for each NSAID. Each of the candidate risk factors were defined and studied in order to evaluate its role in the determination of ADRs from NSAIDs. "Family history of ADRs caused by NSAIDs" was found to be a significant risk factor for the four commonly used NSAIDs: meloxicam, diclofenac, nimesulide, and nabumetone.

CONCLUSION

A retrospective epidemiological survey was useful in detecting the risk factors for ADRs caused by NSAIDs. The study found that different NSAIDs might have different risk factors and that there is no single risk factor universally applicable to all NSAIDs.

Spontaneous Reports of Hypertension Leading to Hospitalisation in Association with Rofecoxib, Celecoxib, Nabumetone and Oxaprozin

BACKGROUND AND OBJECTIVE

Data on file with the US FDA, and other published studies, suggest that the selective cyclo-oxygenase (COX)-2 inhibitor NSAID rofecoxib has a greater hypertensive adverse effect than other NSAIDs, including celecoxib. In this study we describe a pharmacoepidemiologic analysis of spontaneous adverse event reports of acute, clinically serious hypertension (as defined by hospitalisation) reported in association with rofecoxib, celecoxib, nabumetone and oxaprozin. The objective of this analysis is to assess whether postmarketing data are consistent with results of clinical trials. We also collapse cases into series for the identification of possible risk factors for clinically severe, NSAID-associated hypertension.

METHODS

Domestic (US) cases of apparently unconfounded, acute hypertension leading to hospitalisation were collected and reviewed from the spontaneous adverse events database of the FDA for rofecoxib, celecoxib, nabumetone and oxaprozin for the initial 3 years of marketing. Drug use data for the same intervals enabled calculation of reporting rates.

RESULTS

In an analysis of reporting rates, hospitalisation for acute blood pressure (BP) elevation was reported more frequently (3.8-fold) for rofecoxib compared with celecoxib. A total of 34 cases are collapsed into case series. No cases were identified for either nabumetone or oxaprozin. Inspection of reviewed cases for celecoxib and rofecoxib suggest that these patients (average age 72 years) were potentially high-risk candidates for NSAID therapy.

DISCUSSION AND CONCLUSION

During early marketing, hospitalisation for acute BP elevation appears to have been reported more frequently for rofecoxib compared with celecoxib. This is consistent with clinical trial data on file with the FDA, and other published studies that found rofecoxib to have a greater effect on BP than other NSAIDs, including celecoxib. This finding may be particularly relevant in older patients given the prevalence of hypertension and cardiovascular disease in this age group.

[Meta-analysis on the effect and adverse reaction on patients with osteoarthritis and rheumatoid arthritis treated with non-steroidal anti-inflammatory drugs]

OBJECTIVE

To observe the rate of efficacy and adverse drug reaction of non-steroidal anti-inflammatory drugs (NSAIDs) in the population with osteoarthritis and rheumatoid arthritis, based on available clinical data.

METHODS

Using Meta analysis to evaluate the data of effect and safety profile of NSAIDs from 19 articles on randomized clinical trials published from 1990 to 2001 in Chinese journals. The total number of patients enrolled for evaluation on rates of effectiveness and adverse drug reaction were 1 732 and 2 925, respectively.

RESULTS

Data on the effect and safety were comparatively heterogeneous among different kinds of NSAIDs. The effective rates (95% CI) were as follows: nabunetone, 66.7% (61.9% - 71.4%); meloxicam, 68.4% (59.2% - 77.6%); naproxen, 64.5% (59.8% - 69.1%); nimesulide, 79.8% (75.7% - 84.0%); ibuprofen, 77.2% (70.7% - 83.8%); diclofenac, 77.1% (69.2% - 85.0%); oxaprozin, 65.8% (59.5% - 72.0%). Rates of adverse drug reaction (95% CI) were as follows: nabunetone, 16.3% (12.5% - 20.0%); meloxicam, 10.2% (4.2% - 16.2%); naproxen, 29.2% (24.8% - 33.6%); nimesulide, 20.2% (16.0% - 24.3%); ibuprofen, 16.7% (14.7% - 18.8%); diclofenac, 19.3% (11.9% - 26.7%); oxaprozin, 12.7% (8.9% - 16.7%) respectively.

CONCLUSION

The rates of effect and adverse reaction on patients having osteoarthritis and rheumatoid arthritis with NSAIDs treatment would largely depend on the drugs being used. Within 2 - 8 weeks of treatment, the effective rate and rate of adverse drug reaction with commonly used NSAIDs as nabumeton, meloxicam, etc., were 59.2% - 85.0% and 4.2% - 33.6%, respectively.

Safe full-dose one-step nabumetone challenge in patients with nonsteroidal anti-inflammatory drug hypersensitivity

Aspirin and all nonsteroidal anti-inflammatory drugs (NSAIDs) are a chemically heterogeneous group of compounds that share the ability to inhibit the enzyme cyclooxygenase (COX). This inhibitory effect, especially of COX-1, is suggested as the mechanism underlying NSAID-induced hypersensitivity reactions. In this study, we evaluated the safety and convenience of a single full-dose challenge with nabumetone, a selective COX-2 inhibitor, in patients with hypersensitivity to nonselective NSAIDs (ns-NSAIDs). Twenty-four subjects with a history of hypersensitivity reactions to at least two different ns-NSAIDs on two different occasions were enrolled in the study. The patients were otherwise healthy and did not suffer from NSAID- or aspirin-induced asthma or urticaria. All subjects were orally challenged by a single full dose (1000 mg) of nabumetone, monitored closely in the hospital for the next 4 hours and contacted by telephone the next morning and 3-12 months afterward. Twenty-two patients tolerated nabumetone without any reaction during and after the challenge. One patient had a single urticarial lesion and one patient reported mild pruritus without objective signs, both of which resolved spontaneously. Thirteen patients, including the patient who responded with pruritus to the challenge, used nabumetone on several occasions during the follow-up period without any adverse reaction. Our study shows that in patients with a history of aspirin- and ns-NSAID-induced hypersensitivity reaction, a rapid one-step challenge with nabumetone was well tolerated. These initial data support the possibility that a single full dose of nabumetone can be tried as a safe alternative in most patients with a hypersensitivity reaction to ns-NSAIDs.

An open label study to establish dosing recommendations for nabumetone in juvenile rheumatoid arthritis

OBJECTIVE

Once-a-day dosing with nabumetone has been shown to be effective in adults with rheumatoid arthritis. We establish dosing recommendations for nabumetone in children and adolescents with juvenile rheumatoid arthritis (JRA).

METHODS

An open label, multicenter study was conducted in children with JRA aged 2-16 years, weighing > 14 kg, and requiring nonsteroidal antiinflammatory drugs (NSAID) for control of symptoms. NSAID were discontinued one day prior to study initiation to minimize disease flare. Patients received nabumetone 30 mg/kg once daily (as a tablet or a slurry) for 12 weeks. Efficacy assessment evaluations were performed at Weeks 1, 3, 6, and 12, based on the mean change from baseline at the study endpoint for 6 standard rheumatology variables. An overall assessment of efficacy was determined based on the percentage of patients who did not experience a flare, using the 6 rheumatology variables. Since this was an open label study, only descriptive statistics were obtained for efficacy variables. Routine safety assessments were completed for all patients.

RESULTS

In total, 99 patients with JRA were enrolled and 89 completed the study; mean age was 9.2 years. The proportion of nabumetone treated patients with no flare in disease activity during the nabumetone treatment period was 92/99 (93%). Improvement was noted in each efficacy assessment, although statistical evaluations were not performed. The adverse event profile was similar to that reported for nabumetone in adults with RA.

CONCLUSION

Nabumetone 30 mg/kg/day (up to 2000 mg/day) demonstrated a safe profile with no loss of efficacy compared to previous treatment in children with JRA. The dose can be administered by suspending tablets in warm water to create a slurry.

A comparison of the effects of nabumetone vs meloxicam on serum thromboxane B2 and platelet function in healthy volunteers

AIMS

To compare the effects of nabumetone and meloxicam, two cyclo-oxygenase-2 (COX-2) preferential nonsteroidal anti-inflammatory drugs (NSAIDs), on platelet COX-1 activity and platelet function.

METHODS

Twelve healthy volunteers (3 male, 9 female, median age 22 years) participated in an open, randomized, cross-over trial of nabumetone 1000 mg twice daily vs meloxicam 7.5 mg twice daily during 1 week with 2 weeks wash-out. After a second 2 week wash-out period, one dose of indomethacin 50 mg was given as a positive control to check for NSAID induced inhibition of platelet function. COX-1 inhibition was measured as percentage inhibition of serum TXB2 generation in clotting whole blood, and as closure time with use of the platelet function analyser PFA-100. Data are reported as median with range. Paired variables were analysed using Wilcoxons signed rank test.

RESULTS

TXB2 levels decreased significantly after all three medications, but percentage inhibition after nabumetone and indomethacin (88% and 97%, respectively) was significantly higher than after meloxicam (63%) (P<0.05). Closure times increased significantly after administration of all three medications (P<0.05). Increases in closure time after administration did not differ between nabumetone and meloxicam (24% and 14%, respectively), but were significantly larger after indomethacin administration (63%) (P<0.01).

CONCLUSIONS

In the maximum registered dosage, nabumetone inhibits thromboxane production much more than meloxicam, signifying less COX-2 selectivity of the former. However, both nabumetone and meloxicam cause only minor impairment in platelet function in comparison with indomethacin and the difference between them is not significant.

The different patterns of blood pressure elevation by rofecoxib and nabumetone

Hypertension and knee osteoarthritis (OA) are frequent comorbidities. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often used to relieve pain in such patients. In the last decade selective NSAIDs are used more commonly since they lead to less gastrointestinal complications. As has been shown, the treatment with NSAIDs may cause a mild rise of arterial blood pressure (BP). The influence of selective NSAIDs on BP, particularly in hypertensive patients has still to be investigated. The aim of this study was to determine arterial BP changes in patients suffering from stable arterial hypertension and knee OA and treated with rofecoxib or nabumetone. Two groups of patients with knee OA and stable arterial hypertension received either 25 mg rofecoxib once daily or namebutone 2000 mg once daily during the first week of treatment and 1000 mg for the following 3 weeks. Twenty-four hour arterial BP monitoring was performed prior to initiation of treatment and at the end of a 4-week period. The results were that no changes were found in the mean systolic and diastolic characteristics of BP in the rofecoxib treatment group during day time (delta systolic BP -0.4 mm Hg and delta diastolic BP -0.4 mm Hg), while nocturnal BP increased significantly: delta systolic BP +15.7 mm Hg and delta diastolic BP +8.5 mm Hg. The mean systolic arterial pressure in the nabumeton group raised delta systolic BP 2.9 mm Hg in the daytime and 5 mm Hg during the night-time after the treatment. The mean diastolic arterial pressure also rose delta diastolic 3.2 mm Hg and 4.9 mm Hg at day and night hours respectively. In conclusion rofecoxib treatment did not change arterial BP during day time hours, however, there was a distinct increase in night-time systolic and diastolic BP leading to a disappearance of the physiological diurnal variation. Nabumetone caused a moderate increase of day and night BP, without changes in biological diurnal variation.

Nasal function in self-reported chemically intolerant individuals

Nasal function has not yet been investigated under controlled exposures in individuals with self-reported Multiple Chemical Sensitivity (sMCS). Therefore, anterior rhinomanometry and acoustic rhinometry were applied in 12 individuals with sMCS, and 12 age-matched controls. The sMCS individuals and controls were selected on the basis of a standardized questionnaire. Controlled 4-hr exposures to ethylbenzene and 2-butanone were performed during 4 sessions. Exposures were close to the current German threshold limit values, and they approximated odor thresholds. Subjects with sMCS had a significant decrease in the flow value in anterior rhinomanometry, independent of substance and doses, compared with controls. This result suggests somatic reactions to the exposure. The result must be confirmed in additional studies, and pathophysiological examinations must be performed. For these investigations, anterior rhinomanometry was usable, but acoustic rhinometry can be recommended only after sufficient standardization has occurred. Furthermore, biochemical parameters of nasal mucosa must be considered.

Effects of an external exposure to 200 ppm methyl ethyl ketone on nasal mucosa in healthy volunteers

OBJECTIVES

To investigate the effects of an acute exposure to 200 ppm methyl ethyl ketone on the nasal mucosa of healthy volunteers.

METHODS

Nineteen healthy non-smoking men were exposed to 200 ppm methyl ethyl ketone and to a sham exposure in an exposure chamber, using a cross-over design. Mucociliary transport time was determined with the saccharine test. Interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor-alpha (TNFalpha) were measured in nasal secretions. Subjective symptoms were assessed by questionnaire.

RESULTS

Mucociliary transport time was significantly higher (660 vs. 600 s (medians), P = 0.01) after solvent exposure. Concentrations of IL-1beta and IL-8 were insignificantly elevated after exposure (IL-1beta: 83.8 pg/ml vs. 48.1 pg/ml, medians, P = 0.11; IL-8: 14471 pg/ml vs. 11080 pg/ml, P = 0.12), whereas those of IL-6 and TNFalpha remained unchanged. Subjects did not feel any irritation of nasal mucosa.

CONCLUSION

Concentrations of organic solvents not exceeding their MAK values can cause subclinical rhinitis. The secretion of proinflammatory cytokines and impairment of mucociliary transport can explain the development of clinical rhinitis in highly exposed subjects.

Psychophysiological functions of subjects with self-reported multiple chemical sensitivity (sMCS) during experimental solvent exposure

The study examined the assumption of a higher sensitivity of autonomic functions of subjects with self-reported multiple chemical sensitivity (sMCS) during environmental exposure. The hypothesis was tested in a laboratory study with standardized exposures. Twelve healthy male subjects (26.4 +/- 5.4 y) with and 12 male control subjects (25.7 +/- 3.8 y) without self-reported multiple chemical sensitivity (sMCS), selected by a questionnaire, were included in the experimental study. At four different days the subjects were exposed in a random order to solvents for four hours: 10 ppm or 98 ppm ethyl benzene, 10 ppm or 189 ppm 2-butanone. Heart rate and breathing rate were analysed for two 30-minutes periods of vigilance testing at the beginning and end of exposure. In sMCS-subjects both functions were elevated at the beginning of the testing periods with a tendency to decrease over the 30-minutes periods. Control subjects revealed a relatively constant level (breathing rate) and a small increase (heart rate) during the periods. These group differences were obvious for all experimental conditions across substances and levels of exposures. Furthermore, the mean of the breathing rate of sMCS-subjects was generally higher compared to the control subjects. While the assumption of a generally altered sensitivity of autonomic functions of sMCS-subjects to environmental changes seems to be supported, no specific reactions to the type or level of the chemical exposure were found.

Time courses of sensory irritations due to 2-butanone and ethyl benzene exposure: influences of self-reported multiple chemical sensitivity (sMCS)

The individually different effects of exposure to comparable levels of chemicals might be partly explained by dissimilar response sensitivity towards chemicals. Multiple chemical sensitivity (MCS) might be the clinical endpoint of this altered sensitivity. Concerning a subclinical range of chemical sensitivity, 'challenge studies' with people reporting chemical sensitivity are needed to improve the knowledge about such differences. The chemical and general environmental sensitivity questionnaire (CGES) is a standardized screening tool for the selection of this group. In the present study 24 healthy male volunteers, half of them classified as sMCS-subjects, were experimentally exposed to 2-butanone and ethyl benzene at different levels (TLV-level vs. odor threshold). The strength of self-reported sensory irritations (nasal and ocular) and symptoms of bad smell were assessed, prior, during, and after the 4 hours of exposure. The time courses of sensory irritations were affected by sMCS. Across all exposure periods sMCS-subjects showed increasing symptom scores while control-subjects did not. Symptoms of bad smell were affected by three exposure-related factors (substance, level, duration) without any additional influence from the sMCS factor. Starting from these results it could be concluded that the time-depending influence of reported chemical sensitivity is most prominent for subjective data of sensory irritations.

Comparison of cardiovascular thrombotic events in patients with osteoarthritis treated with rofecoxib versus nonselective nonsteroidal anti-inflammatory drugs (ibuprofen, diclofenac, and nabumetone)

Aspirin, nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), and specific cyclooxygenase-2 (COX-2) inhibitors each have distinctive effects on COX-1-mediated thromboxane biosynthesis, the major determinant of platelet aggregation. It is unclear whether these effects are associated with differences in thrombogenic risks. To compare the risk for thrombotic cardiovascular events among patients receiving rofecoxib, nonselective NSAIDs, and placebo, cardiovascular safety was assessed in 5,435 participants in 8 phase IIB/III osteoarthritis trials. The median treatment exposure was 31/2 months. The primary end point assessed was the risk of any arterial or venous thrombotic cardiovascular adverse event (AE). A second analysis assessed differences in the Anti-Platelet Trialists' Collaboration (APTC) events, a cluster end point that consists of the combined incidence of (1) cardiovascular, hemorrhagic, and unknown death; (2) myocardial infarction; and (3) cerebrovascular accident. Similar rates of thrombotic cardiovascular AEs were reported with rofecoxib, placebo, and comparator nonselective NSAIDs (ibuprofen, diclofenac, or nabumetone). In trials that compared rofecoxib with NSAIDs, the incidence of thrombotic cardiovascular AEs was 1.93/100 patient-years in the rofecoxib treatment group compared with 2.27/100 patient-years in the combined nonselective NSAID group. In trials that compared rofecoxib with placebo, the incidence of thrombotic cardiovascular AEs was 2.71/100 patient-years in the rofecoxib group compared with 2.57/100 patient-years in the placebo group. Consistent with the risks of cardiovascular AEs, similar rates of APTC events were reported with rofecoxib, placebo, and comparator nonselective NSAIDs. Thus, in the rofecoxib osteoarthritis development program, there was no difference between rofecoxib, comparator nonselective NSAIDs, and placebo in the risks of cardiovascular thrombotic events.

A comparison of adverse renovascular experiences among osteoarthritis patients treated with rofecoxib and comparator non-selective non-steroidal anti-inflammatory agents

BACKGROUND

Non-selective non-steroidal anti-inflammatory drugs (NSAIDs) inhibit both cyclo-oxygenase (COX) isoenzymes, i.e. COX-1 and COX-2. Rofecoxib, an agent that selectively inhibits COX-2, has been shown to provide equivalent anti-inflammatory and analgesic efficacy to comparator non-selective NSAIDs in osteoarthritis (OA) and other pain models with a significant improvement in gastrointestinal (GI) safety and tolerability. Based on renal physiology studies, it was predicted that rofecoxib would have renovascular effects similar to those observed with non-selective NSAIDs--specifically edema, blood pressure elevation, attenuation of the effects of ACE inhibitors, and (in rare circumstances), acute renal failure might be manifest in a small percentage of patients.

OBJECTIVE

To assess the renovascular safety profile of rofecoxib in OA patients compared to that of non-selective NSAID comparators.

METHODS

Renovascular adverse experiences (AEs) in over 5,000 participants in Phase IIb/III OA clinical trials were reviewed and compared between rofecoxib and non-selective NSAID comparators (ibuprofen 800mg tid, diclofenac 50 mg tid, nabumetone 1,500 mg qd).

RESULTS

The incidence of lower extremity edema (LEE) AEs was generally similar between rofecoxib 12.5 mg/day, rofecoxib 25 mg/day, and non-selective comparator NSAIDs. Treatment discontinuations due to LEE AEs and clinically significant weight gain (> or = 2 kg) associated with LEE AEs were infrequent and generally similar in all active treatment groups. Congestive heart failure (CHF) was rare in all treatment groups. The incidence of hypertension AEs was low in all active treatment groups. Discontinuations due to hypertension AEs and hypertension AEs requiring a change or adjustment in blood pressure medications were similar and uncommon in all treatment groups. There was only a single report of acute renal failure (in the ibuprofen treatment group).

CONCLUSIONS

In the rofecoxib phase IIb/III OA database, the renal safety profile for rofecoxib, a selective inhibitor of COX-2, was generally similar to that of the comparator, non-selective NSAIDs which were studied.

Comparison of the efficacy and safety of naproxen CR and nabumetone in the treatment of patients with osteoarthritis of the knee

OBJECTIVE

To comparre the safety and efficacy of naproxen CR (1,000 mg once daily) with that of nabumetone (1,000 mg once daily) in the treatment of patients with symptomatic knee osteoarthritis(OA).

METHODS

A total of 159 Korean patients (80 in the naproxen CR group and 79 in the nabumetone group) were enrolled in this 4-week, single-blind, controlled, randomized, parallel study and an intention-to-treat model was used for data analysis. Six efficacy parameters were measured: Lequesne index, visual analogue pain scale at rest and atactivity, patient's and physician's global assessment, and time to walk 50 feet.

RESULTS

Significant improvement in all efficacy parameters except time to walk 50 feet occurred at Week 2 and Week 4 in both groups. Themean improvement from baseline at Week 2 and Week 4 for the efficacy variables was not different between naproxen CR and nabumetone group. Twenty-four patients (30%) in the naproxen CR group and 18 patients (22.8%) in the nabumetone group withdrew from the study. Among them, only 1patient in the naproxen CR group terminated the study prematurely due to an adverse event of dyspepsia. No statistically significant difference in the frequency of adverse events, including gastrointestinal symptoms, was observed between these 2 groups during the treatment period. Significant laboratory abnormalities also did not occur during the study period in both groups.

CONCLUSIONS

Naproxen CR is an effective and tolerable drug in the treatment of knee OA. Efficacy and safety profiles are comparable to those of nabumetone.

Gastrointestinal medications and procedures in osteoarthritis patients treated with rofecoxib compared with nonselective NSAIDs

CONTEXT

Patients treated with nonselective cyclooxygenase inhibitors (nonsteroidal anti-inflammatory drugs [NSAIDs]) often experience dyspepsia and upper gastrointestinal (GI) adverse effects, and frequently require GI comedications and diagnostic procedures.

OBJECTIVE

This study combined existing data to test the hypothesis that GI comedications and GI diagnostic procedures occur less frequently in osteoarthritis (OA) patients treated with rofecoxib compared with nonselective NSAIDs.

DESIGN

Combined analysis of 8 randomized controlled clinical trials.

SETTING

Rheumatology and general practice clinics.

PATIENTS

Men and women aged 40 years and older with OA.

INTERVENTIONS

Random assignment to placebo (n = 514), rofecoxib (n = 3357; 12.5, 25, or 50 mg daily combined; average 24.7 mg), or NSAIDs (n = 1564; ibuprofen 800 mg thrice daily, diclofenac 50 mg thrice daily, or nabumetone 1500 mg daily, combined).

MAIN OUTCOME MEASURES

The cumulative incidence of patients using GI comedications (antacids, antispasmodics, antiflatulents, antiregurgitants, H2 antagonists, proton pump inhibitors, sucralfate, prostaglandins, other antiulcer therapy) and needing GI procedures (upper GI barium studies, upper or lower GI endoscopies) over 12 months.

RESULTS

Compared with those treated with NSAIDs, patients treated with rofecoxib had a significantly lower incidence of GI comedication use (17.5% vs 27.0%, P <.001) and GI procedures (3.3% vs 5.3%, P =.02) over 12 months. Similar results were seen in analyses of protocols with placebo; in these studies, rates of GI comedications and procedures were highest with NSAIDs, while those with rofecoxib and placebo were similar to each other.

CONCLUSIONS

OA patients treated with rofecoxib for up to 12 months required significantly less GI comedication and significantly fewer GI procedures than those treated with NSAIDs.

Solvent exposures at shoe factories and workshops in Hebron City, West Bank

Exposure to organic solvents has been reported to increase the risks for acute and chronic health effects among shoe industry workers. In developing countries, protection against chemical exposures is often not provided. The study was conducted to identify working conditions and estimate the concentrations of organic solvents used in shoe factories and workshops in Hebron City. Personal interviews containing questions related to personal protective equipment (PPE) were used to identify working conditions, and samples collected from factories and workshops were analyzed using gas chromatography. Geometric means (GMs) were calculated for the solvents. Six major organic solvents were detected in the factories. Acetone (GM = 51.5 mg/m3, GSD = 3.82) was common in gluing tasks. Dichloromethane (GM = 47 mg/m3, GSD = 2.62) was common in cleaning tasks. Heptane, methylethyl ketone, n-hexane, and toluene were common in gluing tasks. Four major organic solvents were detected in the workshops: acetone (GM = 32.3 mg/m:3, GSD = 6.33), toluene (GM = 70.3 mg/m3, GSD = 3.06), n-hexane (GM = 19.4 mg/m3:, GSD = 2.65), and methylethyl ketone (GM = 130 mg/mM3, GSD = 1.5). 81% of the factory workers had never used respiratory protective equipment, and 92% had never used work clothes. 97% of the workers in the workshops had never used respiratory protective equipment, 94% had never worn gloves, and 90% had never used work clothes. Exposures to solvents in the absence of personal Protective equipment, tasks barriers, and mechanical ventilation can adversely affect health.

[Comparison of the efficacy and safety of nabumetone and diclofenac sodium in the treatment of patients with rheumatoid arthritis]

OBJECTIVE

To compare the efficacy and safety of nabumetone and diclofenac sodium in the treatment of patients with rheumatoid arthritis (RA).

METHODS

A hundred and twenty-five patients with active RA were enrolled in a randomized, open-label, controlled, multicenter, 12-week study treating with nabumetone (1 000 mg/day) or diclofenac sodium (75 mg/day). Clinical assessments were performed before beginning therapy, and after 4, 8, and 12 weeks of treatment. Endoscopy was performed respectively before and 12 weeks after the medication in all patients.

RESULTS

The total efficacy rate of nabumetone was as high as that of diclofenac sodium (92.31% vs 88.52%, chi(2) = 1.114, P = 0.573). nabumetone treated patients showed significant improvement both in erythrocyte sedimentation rate (38.74 mm/1 h vs 25.56 mm/1 h, F = 14.005, P < 0.01 in nabumetone group, and 42.74 mm/1 h vs 34.36 mm/1 h, F = 3.811, P > 0.05, in diclofenac sodium group respectively) and C-reactive protein (2.08 mg/dl vs 1.21 mg/dl, F = 6.495, P < 0.05 in nabumetone group; and 3.29 mg/dl vs 2.31 mg/dl, F = 2.968, P > 0.05 in diclofenac sodium group respectively). The variety and incidence of gastrointestinal (GI) symptoms attributed to nabumetone was comparable to that of diclofenac sodium. The mean score of endoscopic lesions in the nabumetone group was significantly lower in the end of the treatment than those of their base line scoring (P < 0.01), and there was no significant change with regard to the diclofenac sodium group. The incidence of ulcer disease associated with nabumetone was 0% and 2.70% with diclofenac sodium.

CONCLUSION

nabumetone is as effective as diclofenac sodium in controlling the signs and symptoms of RA. However, GI lesions under the endoscope in the nabumetone group seemed to be less severe than that of the diclofenac sodium group.

Treatment of elderly patients with nabumetone or diclofenac: gastrointestinal safety profile

GOALS

To evaluate the efficacy and gastrointestinal safety of nabumetone and diclofenac in the treatment of elderly patients with osteoarthritis, participating in a 3-month efficacy trial.

BACKGROUND

Elderly patients have an elevated risk for developing gastrointestinal complications with chronic use of nonsteroidal anti-inflammatory drugs.

STUDY

This was a randomized, double-blind, parallel-group, multicenter study with a 3-to 14-day placebo washout period and a 12-week active treatment phase. Patients 65 years or older with moderate-to-severe osteoarthritis of the knee or hip were randomized to receive 1,000 to 2,000 mg/d of nabumetone or 100 to 150 mg/d of diclofenac. The primary efficacy parameters were the percent of patients improved using a Patients' and Physicians' Global Assessment at endpoint. Gastrointestinal safety was assessed by the incidence of gastrointestinal symptoms and adverse events.

RESULTS

Three hundred thirty-five patients (mean age = 72 years) with active osteoarthritis were enrolled. There were no statistically significant differences between the two treatment groups in any of the primary efficacy variables. However, differences between the groups were apparent in the frequency of adverse gastrointestinal events. Two patients in the diclofenac group had evidence of gastrointestinal bleeding and/or ulcer compared with none in the nabumetone group. In addition, significantly more (p < 0.05) patients (4%) receiving diclofenac had alanine transaminase values more than twice the upper limit of normal at endpoint compared with patients receiving nabumetone (0%).

CONCLUSIONS

Nabumetone was as effective as diclofenac in the treatment of elderly patients with moderate-to-severe osteoarthritis. However, the gastrointestinal safety profile of nabumetone was superior to that of diclofenac with respect to elevation of liver enzymes.

A multicenter, randomized, controlled trial to evaluate the safety profile, tolerability, and efficacy of rofecoxib in advanced elderly patients with osteoarthritis

This 6-week study was conducted to test the efficacy, safety, and tolerability of rofecoxib (a selective COX-2 inhibitor) compared to nabumetone (a non-selective NSAID) and placebo in osteoarthritis (OA) patients aged 80 and older. Three hundred forty-one patients, mean age 83 years, were randomized. Allocations were made in an approximately 1:2:1:2 ratio (placebo: 12.5 mg rofecoxib: 25 mg rofecoxib: 1500 mg nabumetone). Least square mean changes from baseline in the primary efficacy endpoint, Patient Global Assessment of Disease Status, were as follows (with negative numbers indicating improvement): -14.85 mm for placebo; -25.34 mm for 12.5 mg rofecoxib; -25.40 mm for 25 mg of rofecoxib; and -25.95 mm for nabumetone (p<0.001 for all active treatments vs placebo.) Results from secondary endpoints, including the 3 WOMAC sub-scales (pain, stiffness, and disability) and the Investigator Global Assessment of Disease Status, were consistent with those for the primary endpoint. No significant between-group differences were observed in the proportions of patients who discontinued treatment due to either clinical or laboratory adverse experiences. Renal safety (edema and hypertension adverse experiences) was similar for rofecoxib and nabumetone. No gastroduodenal ulcers occurred; however, the demonstration of gastrointestinal risk with rofecoxib or nabumetone was beyond the scope of this trial. We conclude that in patients 80 years and older, rofecoxib, 12.5 mg and 25 mg once daily, demonstrated clinical efficacy for the treatment for OA as did 1500 mg of nabumetone. Rofecoxib and nabumetone were generally well tolerated in this elderly population.

Effect of nabumetone and aspirin on colonic mucosal bleeding time

BACKGROUND

The management of patients taking aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) who require colonoscopy remains controversial because of concerns over bleeding after biopsy or polypectomy.

AIM

To determine whether patients using the NSAID nabumetone, a non-acidic prodrug with mixed activity against cyclooxygenase-1 (COX-1) and COX-2, exhibited prolonged mucosal bleeding times and how this might compare with mucosal bleeding times in patients using aspirin.

METHODS

We assessed triplicate mucosal bleeding times in patients undergoing screening flexible sigmoidoscopy. We compared 90 patients who had taken no aspirin or NSAIDs within the previous 2 weeks, to 60 patients who had received nabumetone 1 g b.d. by mouth for the previous 2 weeks, and 30 patients who had taken 325 mg aspirin daily for the previous 2 weeks. In each case, the investigator performing the study was blinded to the patient's medication.

RESULTS

Mucosal bleeding times did not differ significantly among control or nabumetone-using patients. However, the patients receiving aspirin exhibited significant prolongation. Mucosal bleeding time correlated statistically significantly, but weakly, with skin bleeding time.

CONCLUSIONS

Nabumetone does not appear to prolong mucosal bleeding time after mucosal pinch biopsy, and skin bleeding time does not reliably screen for prolonged mucosal bleeding time.

Management of nonsteroidal anti-inflammatory drug-related peptic ulcer bleeding

Nonsteroidal anti-inflammatory drugs (NSAIDs) have superseded Helicobacter pylori infection as the most important cause of peptic ulcer bleeding. Eradication of H. pylori in NSAID users will not affect ulcer healing. In high-risk patients with a history of ulcer bleeding, curing H. pylori infection alone without acid suppression has substantially reduced the risk of rebleeding caused by low-dose aspirin but not nonaspirin NSAIDs. In a study comparing the safety profile of misoprostol in combination with NSAID against nabumetone in high-risk patients with a history of ulcer bleeding, both strategies were unable to confer significant protection against the risk of rebleeding.

[Properties and features of nabumetone]

Nabumetone is a nonsteroidal anti-inflammatory drug (NSAID) of the 2,6-disubstituted naphthylalkanone class. It is a prodrug metabolised to an active metabolite, 6-methoxy-2-naphthylacetic acid (6-MNA), which preferentially inhibits cyclo-oxygenase-2 (COX-2) and has both anti-inflammatory and analgesic properties. The efficacy of nabumetone is comparable to that of other NSAIDs currently marketed in France for the treatment of rheumatoid arthritis and osteoarthritis. Nabumetone is metabolised to 6-MNA by extensive first-pass metabolism. This active metabolite is subsequently conjugated and excreted in urine. 6-MNA does not undergo enterohepatic recirculation, which may have implications for comparative gastrointestinal toxicity. Substantial concentrations of 6-MNA are achieved and maintained in synovial fluid, which is close to the proposed site of action in chronic arthropathies. The long plasma half-life of 6-MNA (20 to 24 hours) and its persistence in synovial fluid facilitate a once-daily dosage regimen. Nabumetone compares favourably with other NSAIDs with respect to its renal and gastrointestinal adverse effect profile, although increased clinical vigilance of drug-related adverse events relating to these organ systems is still recommended. In addition, in vitro experiments have shown this drug to have a good cartilage tolerability profile. Whether nabumetone has clinical utility in cardiovascular disorders remains to be determined. The unique pharmacokinetic and pharmacodynamic properties of nabumetone make it a welcome addition to the growing arsenal of drugs used in the treatment of chronic arthropathies. There may be clinical advantages in terms of the relative tolerability profile of nabumetone, given that this drug has a low COX-2/COX-1 ratio compared with other nonselective NSAIDs.

[Gastrointestinal tolerance of nonsteroidal anti-inflammatory agents]

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective antipyretic, analgesic and anti-inflammatory agents. One of the major concerns regarding the use of these compounds is the incidence of gastrointestinal (GI) adverse effects, ranging from dyspepsia to the serious and potentially life threatening complications of ulcers, haemorrhages, and perforations. Thus, the prevention and/or treatment of upper GI damage is estimated to increase the overall cost of NSAID therapy by at least 40%. The pathogenesis of NSAID-induced gastroduodenal mucosal injury appears to involve both topical and systemic mechanisms. The former is related to the acidic nature of most NSAIDs, which promotes the accumulation of ionised molecules (ion trapping) within the mucosal cells. Topical mucosal injury may also occur as a result of biliary excretion of active NSAID metabolites. The systemic effect has, however, the predominant role. It is mediated through cyclo-oxygenase (COX) inhibition and a subsequent decrease in gastroprotective prostaglandins. Fortunately, 2 forms of COX enzymes, designated COX-1 and COX-2, have been recognised. COX-1 appears to function as a house-keeping enzyme, whereas COX-2 is primarily induced by inflammatory stimuli and mitogens in various cells, including macrophages and synovial cells. Accordingly, the inhibition of COX-2 would result in anti-inflammatory effects, whereas gastroduodenal ulceration is thought to be related to the inhibition of COX-1. Animal data have suggested that nabumetone has a low ulcerogenic potential in comparison with other available NSAIDs. This feature was further supported by controlled clinical trials as well as epidemiological studies. The relative GI safety of nabumetone may be attributed to its lack of direct and indirect topical effects because of its nonacidic nature and absence of enterohepatic recirculation. Furthermore, the active metabolite [6-methoxy-2-naphthylacetic acid (6-MNA)] may be gastro-sparing as a result of its property of COX-2 preferential inhibition.

[Rationale for using nabumetone and clinical experience]

Nabumetone's position as one of the most commonly used nonsteroidal anti-inflammatory drugs (NSAIDs) in the world today is based upon over a decade of clinical experience. The popularity of this drug lies in both its unique pharmacokinetic profile and special safety features in pharmacodynamic terms. This nonacidic prodrug with an active 6-methoxy-2-naphthylacetic acid (6-MNA) metabolite has COX-2 preferential features and is also devoid of enterohepatic recirculation. It is felt that these characteristics have provided the basis for its unique long term tolerability, documented in various at-risk osteoarthritis and rheumatoid arthritis populations. The excellent tolerability of nabumetone and its 24-hour half-life, which provides the advantages of a once-daily dosage regimen, make it uniquely suitable for long term anti-inflammatory therapy in arthritis. The tolerability profile of nabumetone has also demonstrated clear cost-effectiveness advantages, as confirmed by comparative and epidemiological studies. Selective COX-2 NSAIDs are likely to prove more expensive because of the increasing costs and demands of clinical research prior to FDA approval. These higher costs may limit and influence patient access, depending on the healthcare delivery system, and many years of experience will be required to document the putative tolerability advantages of these newer COX-2 inhibitor agents. In the meantime, it is comforting that nabumetone has established such an advantageous tolerability profile together with acknowledged efficacy.

Nabumetone: new preparation. Just another NSAID

(1) Nabumetone is a nonsteroidal antiinflammatory drug recently marketed in France. It has been available in other countries for about 15 years. Its licensed indications cover chronic inflammatory rheumatism and osteoarthritis. (2) The clinical file is bulky, but available trials in chronic inflammatory rheumatism involve only rheumatoid arthritis. (3) In rheumatoid arthritis (4 trials) and osteoarthritis (11 trials), nabumetone was no more effective than other nonsteroidal antiinflammatory drugs with which it was compared. (4) Clinical trial data, pharmacovigilance surveys and epidemiological studies suggest that nabumetone is among the antiinflammatory drugs with the least gastrointestinal adverse effects, but it has not yet been shown that they are less frequent than those of diclofenac, etodolac, ibuprofen or sulindac.