Oral gold: a comparison with placebo and with intramuscular sodium aurothiomalate

Comparative study of intramuscular gold and methotrexate in a rheumatoid arthritis population from a socially deprived area

OBJECTIVE

To compare the risk-benefit ratio of intramuscular gold (gold sodium thiomalate (GST)) and methotrexate (MTX) in a population with rheumatoid arthritis (RA) from a deprived area.

METHODS

Patients with active RA were randomly assigned to open treatment with GST or MTX. Clinical and laboratory assessment was performed at 0, 12, 24, and 48 weeks. Results were analysed on an intention to treat basis.

RESULTS

141 patients were recruited-72 were randomly allocated to GST and 69 to MTX. There were no statistically significant differences found in either the clinical or demographic variables at baseline. At 48 weeks 31 (43%) patients continued to receive GST and 43 (62%) MTX. The median MTX dose achieved was 10 mg. Gold caused significantly more withdrawals for toxicity (43% GST v 19% MTX, p=0.0026, log rank test). Both groups experienced a significant improvement in erythrocyte sedimentation rate, C reactive protein, Ritchie Articular Index, and pain score by 24 weeks (p<0.001, Friedman test). Although a trend towards an improved Health Assessment Questionnaire (HAQ) score and global wellbeing was seen in both groups, this did not reach statistical significance. No differences in efficacy were found when the two groups were compared (Mann-Whitney).

CONCLUSION

GST and low dose MTX showed equivalent efficacy, but toxicity was more common in patients treated with GST. GST, although more toxic, remains a useful alternative for patients in whom MTX is contraindicated.

Auranofin versus placebo in rheumatoid arthritis

BACKGROUND

Auranofin is an oral gold compound used for the treatment of rheumatoid arthritis RA. The use of auranofin has declined in the past few years, perhaps due in part to conflicting results from different studies.

OBJECTIVES

To estimate the short-term efficacy and toxicity of auranofin for the treatment of (RA) SEARCH STRATEGY: We searched MEDLINE and EMBASE up to December 1998, the Cochrane Controlled Trials Register (CCTR) version 4, 1998, and the Cochrane Musculoskeletal Group Specialized Register. A hand search was also done of the reference lists of the trials retrieved from the electronic search.

SELECTION CRITERIA

All randomized controlled trials (RCTs) and controlled clinical trials (CCTs) comparing auranofin against placebo in patients with RA DATA COLLECTION AND ANALYSIS: The methodological quality of the trials was assessed using a validated assessment tool (Jadad 1996). Rheumatoid arthritis outcome measures were extracted from the publications for the 6-month endpoint. The pooled analysis was performed using standardized mean differences (SMDs) for joint counts, pain and global assessments. The weighted mean difference (WMD) was used for ESR. Toxicity was evaluated with pooled odds ratios for withdrawals and adverse reactions. A chi-square test was used to assess heterogeneity among trials. In the presence of heterogeneity, random effects models were used. Otherwise, the data was pooled assuming fixed effects.

MAIN RESULTS

A statistically significant benefit was observed for auranofin when compared to placebo for tender joint scores, pain, patient and physician global assessments and ESR. The SMD between treatment and placebo was -0.39 (95% CI -0.54, -0.25) for tender joint scores, -0.08 (95% CI -0.22, -0.07) for swollen joint scores, and the WMD was -4.68 (95% CI -6.59, -2.77) for pain scores and -9.85mm (95% CI -16.46, -3.25) for ESR. Withdrawals from adverse reactions were 1.5 times higher in the auranofin group OR = 1.52 (95% CI 0.94, 2.46) but this result was not statistically significant. Patients receiving placebo were three times more likely to discontinue treatment because of lack of efficacy than patients receiving auranofin: OR=0.31 (95% CI: 0.21, 0.44).

REVIEWER'S CONCLUSIONS

Auranofin appears to have a small clinically and statistically significant benefit on the disease activity of patients with RA. The beneficial effects appear to be modest compared to drugs such as methotrexate or parenteral gold. Its effects on long term health status and radiological progression are not clear at this time.

Assessing the relative sensitivity to change of rheumatoid arthritis activity measures: is the type of treatment an important third variable?

Observational studies and meta-analyses of controlled clinical trials have been used to identify which measures of rheumatoid arthritis activity are most sensitive to change. These analyses often pool studies of different drugs, although it is not known if arthritis activity measures are differentially responsive to different drugs. In meta-analyses, estimates of the relative sensitivity to change of different measures may also be confounded by differences in drug efficacy, if studies of different drugs contribute different measures to the meta-analysis. To determine if the type of treatment acts as an important effect modifier or confounder in studies of the relative sensitivity to change of arthritis activity measures, we computed effect sizes for four measures (weighted tender joint count, grip strength, duration of morning stiffness, and erythrocyte sedimentation rate) used in each of 16 trials of five different disease-modifying antirheumatic drugs (methotrexate, sulfasalazine, cyclosporin A, intramuscular gold, and D-penicillamine) in rheumatoid arthritis. In a complete factorial analysis of variance, effect sizes differed significantly among drugs (p = 0.0006), but differed only marginally among measures (p = 0.08). No interaction was detectable between drugs and measures. These results suggested that effect modification by drugs was not present, but that pooled estimates of the sensitivity to change of different measures may be confounded in meta-analyses, if trials of more efficacious drugs contribute different measures than trials of less efficacious drugs. In a similar analysis of 26 trials of nine nonsteroidal anti-inflammatory drugs, we found significant differences in effect sizes among measures (p < 0.0001), but no differences among drugs (p = 0.96), and no interaction between drugs and measures. This study suggests that pooled analyses of the relative sensitivity to change of arthritis activity measures based on trials of different disease-modifying drugs may be confounded by drug effects, but confounding by drug effects is unlikely if these meta-analyses are based on trials of different nonsteroidal anti-inflammatory drugs. Although the power of these analyses to detect small interaction effects was limited, effect modification by drugs was not observed, indicating that the measures we examined were not strongly differentially responsive to different drugs.

Effect of oral gold salt therapy on bile acid absorption in rheumatoid arthritis patients

Several studies pointed out an altered stool pattern as the most common side effect of auranofin therapy. The major mechanism in the aetiology of auranofin-induced impairment in bowel habit seems to be the inhibition of Na+/K+ ATPase in the gut. In vitro experiments proved that auranofin can affect active bile acid (BA) reabsorption in rat terminal ileum; this action, due to the ability of the drug to reduce Na+ pump activity by inhibiting Na+/K+ ATPase, may make a significant contribution to the auranofin-induced diarrhoea. The ability of auranofin to reduce the Na+ gradient necessary for active BA reabsorption, however, could cause a decrease of serum BA levels in patients taking auranofin before or without the development of an overt diarrhoea. We measured fasting and postprandial serum conjugated BA levels in 10 female rheumatoid arthritis patients before and after one month and two months' auranofin treatment. No patient developed diarrhoea during the chrysotherapy. When oral gold salt therapy was started, we observed a slight decrease in serum BA levels, but difference was not statistically significant. We can conclude that auranofin therapy does not cause BA malabsorption in patients who do not develop diarrhoea during the treatment.

A three year follow up of patients allocated to placebo, or oral or injectable gold therapy for rheumatoid arthritis

Ninety patients randomly allocated to receive auranofin, matching placebo, or sodium aurothiomalate have been followed up for three years. Inefficacy led to cessation of treatment in 14 patients receiving auranofin, 27 receiving placebo, and one receiving sodium aurothiomalate. Twenty seven of the patients receiving placebo were reallocated within the study and 16 continued therapy at three years. This group showed similar statistically significant improvement in clinical and laboratory parameters at one, two, and three years to those on an active drug from the outset. Patients who discontinued auranofin because of inefficacy were offered sodium aurothiomalate therapy--eight patients in this group completed three years of treatment on sodium aurothiomalate and showed significant improvement in some but not all parameters. A hand radiograph erosion score showed a deterioration in 80% of patients remaining on auranofin, 75% of those on sodium aurothiomalate, and 80% of the original placebo group who continued an active drug for three years. Although more patients discontinued auranofin over the study period because of inefficacy, no difference could be shown between the degree of improvement in the subgroup who remained on auranofin and those receiving sodium aurothiomalate. No disadvantage in outcome could be shown for patients originally assigned to placebo.

Effects of aurothioglucose and auranofin on radiographic progression in rheumatoid arthritis

Radiographic films of 40 patients participating in a single centre patient blind study of auranofin versus aurothioglucose were evaluated in a random order by one reader. The two treatment groups were comparable with respect to number of erosions and total radiographic score at the start of the study. Only in the auranofin-treated patients was a statistically significant increase in the mean number of new erosions (p less than 0.001 at 6 months and p less than 0.01 at 12 months treatment, paired t-test) as well as in the total radiographic score (p less than 0.01 at 6 and 12 months treatment, paired t-test) observed. Results of this study confirm that parenteral gold compounds do retard radiographic progression of joint destruction in the treatment of rheumatoid arthritis. The effects on radiographic progression shown in this study are in agreement with other reports which, based on clinical and biochemical parameters, have shown that auranofin is somewhat less effective than the injectible gold salts.