Effect of chrysotherapy on the lower gastrointestinal tract: a review

Gold nanoparticles: a revival in precious metal administration to patients

Gold has been used as a therapeutic agent to treat a wide variety of rheumatic diseases including psoriatic arthritis, juvenile arthritis, and discoid lupus erythematosus. Although the use of gold has been largely superseded by newer drugs, gold nanoparticles are being used effectively in laboratory based clinical diagnostic methods while concurrently showing great promise in vivo either as a diagnostic imaging agent or a therapeutic agent. For these reasons, gold nanoparticles are therefore well placed to enter mainstream clinical practice in the near future. Hence, the present review summarizes the chemistry, pharmacokinetics, biodistribution, metabolism, and toxicity of bulk gold in humans based on decades of clinical observation and experiments in which gold was used to treat patients with rheumatoid arthritis. The beneficial attributes of gold nanoparticles, such as their ease of synthesis, functionalization, and shape control are also highlighted demonstrating why gold nanoparticles are an attractive target for further development and optimization. The importance of controlling the size and shape of gold nanoparticles to minimize any potential toxic side effects is also discussed.

The moderate intestinal side effects of auranofin do not require prophylactic therapy with a bulkforming agent. Dutch Ridaura Study Group

Incidences of diarrhoea and loose stools are reported up to 50% in patients starting treatment with auranofin. Moreover, +/-4% of patients discontinue treatment because of severe diarrhoea. We investigated whether a water binding agent would diminish the incidence of loose stools and diarrhoea. Endpoints were the patient's general impression of the quality of stools and a daily assessment of stool's frequency/consistency and adverse events. Secondly, some disease activity parameters were used to evaluate whether the bulkforming agent influences the efficacy of auranofin. In this study 269 patients suffering from Rheumatoid Arthritis (RA) were treated with auranofin 6 mgr daily for a period of six months. Simultaneously the patients were randomly treated with either a bulkforming agent (Volcolon: psyllium fibres) or placebo. Results show a 15% incidence of loose stools and diarrhoea during treatment with auranofin. During the treatment period the patients' general impression of defecation consistency showed a shift to softer types. The changes in defecation consistency was not significantly different between groups (Intention-to-treat analysis: C2=4.01; p=0.13). Also, the percentage of patients experiencing episodes of diarrhoea (reported as an adverse experience) was not different (14% of the patients treated with bulkformer versus 15% with placebo). During the first month 7% (n=5) of placebo treated patients reported short episodes of watery stools versus none in the bulkformer treated group. The percentage of days with loose or watery stools, reported on the diary cards, was consistently lower in bulkformer treated patients. Both groups improved equally with respect to disease activity parameters. Sixty-eight percent of patients continued auranofin treatment after the study period. In conclusion, these data do not support adjuvant therapy with a bulkforming agent on initiation of auranofin therapy. The overall low incidence of loose stools and diarrhoea suggests that a dose increase to 9 mgr daily is an option to enhance the efficacy of auranofin treatment.

Management of adverse effects of disease-modifying antirheumatic drugs

Therapy with disease modifying antirheumatic agents (DMARDs) is often complicated by the occurrence of adverse effects. Although risk factors for several DMARDs have been reported, the prediction of adverse drug reactions is not yet possible. Therefore regular monitoring remains mandatory. Monitoring for adverse effects to DMARDs usually includes one or more of the following: blood count, liver, kidney, urine or ophthalmologic tests. Since most adverse reactions occur during the first few months of treatment, monitoring should be more intense and frequent in this initial phase. Some adverse effects are dose-dependent, and therefore dosage reduction may help alleviate these. Others are idiosyncratic, and often necessitate drug withdrawal. Except for (hydroxy)chloroquine-induced retinopathy and methotrexate-induced liver cirrhosis, most adverse reactions to DMARDs are fortunately reversible.

Comparing the strengths and weaknesses of observational and experimental studies using a postmarketing surveillance study as a protypic example

A recent prospective, observational study in rheumatoid arthritis patients indicated that the addition of hydroxychloroquine to either aspirin or methotrexate therapy decreased the incidence of hepatic enzyme abnormalities. This interesting finding is of potential clinical importance, but its validity needs to be examined in terms of the potential confounders inherent in observational studies. Although one of the study's strengths is its derivation from "real-life" data, some potential confounders that might weaken the data include a need to examine whether any scientific rationale can be discerned for the observation; examination of control-case matching (issues of randomization and baseline disease characteristics); the potential for attribution bias; data-collection methods (prospective versus retrospective, uniform versus chart review); and equivalency of treatment protocols, dosing regimens, and concomitant medications. Potential scientific rationale exists for the observed interaction, and data collection is both uniform and prospective. These strengths are confounded by the inevitable lack of randomization in observational studies, the potential for differences in baseline disease characteristics, attribution bias, a lack of controlled dosing regimens and treatment protocols, and an assumption that all nonsteroid antiinflammatory drugs are alike (which is not true). On balance, the hypothesis generated by these data is compelling enough to deserve further testing in both observational and experimental settings.

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.