Diabetes and gout: efficacy and safety of febuxostat and allopurinol

AIM

Assess influences of demographics and co-morbidities of gout patients with or without diabetes on safety and efficacy of urate-lowering agents.

METHODS

Post-hoc analysis of 312 diabetic and 1957 non-diabetic gout patients [baseline serum urate levels (sUA) ≥8.0 mg/dl] enrolled in a 6-month randomized controlled trial comparing urate-lowering efficacy (ULE) and safety of daily xanthine oxidase inhibitors (XOIs) febuxostat (40 mg or 80 mg) and allopurinol (200 mg or 300 mg). We compared baseline demographic, gout and co-morbid characteristics, ULE, and safety of XOI treatment in diabetic and non-diabetic gout patients. ULE was measured by the proportion of diabetic and non-diabetic patients in each treatment group achieving final visit sUA < 6.0 mg/dl. Safety was monitored throughout the trial.

RESULTS

Diabetic gout patients were older, more frequently female, and had longer gout duration. Co-morbidities were more frequent among diabetic patients: cardiovascular disease; impaired renal function; hyperlipidemia; and obesity (body mass index >30 kg/m²) (p < 0.001 for all comparisons). Febuxostat 80 mg ULE exceeded that of febuxostat 40 mg or allopurinol (p < 0.050) at all levels of renal function, achieving sUA goal range in the majority of diabetic and non-diabetic patients. Diabetics and non-diabetics reported self-limiting diarrhoea and URIs as the most common adverse events.

CONCLUSIONS

Despite higher co-morbidity rates in diabetic patients, febuxostat and allopurinol were safe in both groups at the doses tested. Febuxostat 80 mg achieved sUA <6.0 mg/dl more often than febuxostat 40 mg or allopurinol at commonly prescribed doses.

Febuxostat in the treatment of gout: 5-yr findings of the FOCUS efficacy and safety study

OBJECTIVES

This 5-yr study assessed urate-lowering and clinical efficacy and safety of long-term febuxostat therapy in subjects with gout. The primary efficacy end-point was reduction to and maintenance of serum urate (sUA) levels < 6.0 mg/dl.

METHODS

Subjects who completed a previous 28-day study were entered into an open-label extension study and initially received febuxostat 80 mg daily. Between Weeks 4 and 24, dosing could be adjusted to febuxostat 40 or 120 mg. All subjects received gout flare prophylaxis during the first 4 weeks. Gout flares were recorded and treated throughout the study, and sUA, baseline tophi and safety were monitored.

RESULTS

Among 116 subjects initially enrolled, dose adjustments were made for 44 (38%) subjects. As a result, 8 subjects received febuxostat 40 mg, 79 received 80 mg, and 29 received 120 mg daily maintenance dose. At 5 yrs, 93% (54/58) of the remaining subjects had sUA < 6.0 mg/dl. Fifty-eight subjects (50%) discontinued prematurely; 38 did so in the first year. Thirteen subjects withdrew due to an adverse event. Sustained reduction of sUA was associated with nearly complete elimination of gout flares. In 26 subjects with a tophus at baseline, resolution was achieved in 69% (18/26) by last visit on study drug at any point during the study (Final Visit). There were no deaths reported during the study.

CONCLUSIONS

Long-term treatment with febuxostat resulted in durable maintenance of sUA < 6.0 mg/dl for most subjects. There was nearly complete abolition of gout flares in patients completing the study. Baseline tophi resolved in a majority of subjects.

Magnetic resonance imaging in the quantitative assessment of gouty tophi

Measurements of tophus size can be important in monitoring the course of gout therapy, as tophus resolution is proposed as one measure of success of treatment. This multicentre study assessed the intra- and interreader reproducibility of quantitative tophus volume measurements from magnetic resonance images (MRI) in subjects with palpable gouty tophi. Subjects first underwent radiographic imaging of a selected tophus followed by MRI before and at <or=5, 10 and 20-min after gadolinium administration. After choosing optimal parameters, subjects underwent pre- and postgadolinium-enhanced MRIs of a selected tophus on two occasions separated by 5-10 days. Unenhanced spin-echo images provided satisfactory tophi images and were less subject to interfering artefacts than gadolinium-enhanced gradient-echo images. Intrareader reproducibility was excellent, with no statistically significant difference in mean tophus volume between visits (mean difference - 0.05 +/- 0.97 cm3). A small but statistically significant difference in interreader mean tophus volume was detected (mean difference 0.89 +/- 2.05 cm3; p < 0.05). MRI can quantify tophus size in gout and deserves further comparison with other techniques for tophus size monitoring in assessing effects of gout therapy.

Investigating a memory-based account of negative priming: support for selection-feature mismatch

Using typical and modified negative priming tasks, the selection-feature mismatch account of negative priming was tested. In the modified task, participants performed selections on the basis of a semantic feature (e.g., referent size). This procedure has been shown to enhance negative priming (P. A. MacDonald, S. Joordens, & K. N. Seergobin, 1999). Across 3 experiments, negative priming occurred only when the repeated item mismatched in terms of the feature used as the basis for selections. When the repeated item was congruent on the selection feature across the prime and probe displays, positive priming arose. This pattern of results appeared in both the ignored- and the attended-repetition conditions. Negative priming does not result from previously ignoring an item. These findings strongly support the selection-feature mismatch account of negative priming and refute both the distractor inhibition and the episodic-retrieval explanations.

Investigating a memory-based account of negative priming: support for selection-feature mismatch

Using typical and modified negative priming tasks, the selection-feature mismatch account of negative priming was tested. In the modified task, participants performed selections on the basis of a semantic feature (e.g., referent size). This procedure has been shown to enhance negative priming (P. A. MacDonald, S. Joordens, & K. N. Seergobin, 1999). Across 3 experiments, negative priming occurred only when the repeated item mismatched in terms of the feature used as the basis for selections. When the repeated item was congruent on the selection feature across the prime and probe displays, positive priming arose. This pattern of results appeared in both the ignored- and the attended-repetition conditions. Negative priming does not result from previously ignoring an item. These findings strongly support the selection-feature mismatch account of negative priming and refute both the distractor inhibition and the episodic-retrieval explanations.

Negative priming for obsessive-compulsive checkers and noncheckers

Negative priming--the slowing of a response to an item that was recently ignored--was investigated in three groups: obsessive-compulsive disorder (OCD) checkers, OCD noncheckers, and nonclinical control participants. All groups performed both a standard negative priming task, selecting targets based on a perceptual feature (i.e., color), and a modified negative priming task, selecting targets based on a semantic feature (i.e., referent size). All three groups demonstrated significant negative priming in both tasks, although the negative priming was much larger in the novel, semantic task than in the common, perceptual one. The findings suggest that patients with OCD do not demonstrate impairments in negative priming, contrary to earlier claims (Enright & Beech, 1990, 1993a, 1993b; Enright, Beech, & Claridge, 1995).

Negative priming for obsessive-compulsive checkers and noncheckers

Negative priming--the slowing of a response to an item that was recently ignored--was investigated in three groups: obsessive-compulsive disorder (OCD) checkers, OCD noncheckers, and nonclinical control participants. All groups performed both a standard negative priming task, selecting targets based on a perceptual feature (i.e., color), and a modified negative priming task, selecting targets based on a semantic feature (i.e., referent size). All three groups demonstrated significant negative priming in both tasks, although the negative priming was much larger in the novel, semantic task than in the common, perceptual one. The findings suggest that patients with OCD do not demonstrate impairments in negative priming, contrary to earlier claims (Enright & Beech, 1990, 1993a, 1993b; Enright, Beech, & Claridge, 1995).

Negative priming effects that are bigger than a breadbox: attention to distractors does not eliminate negative priming, it enhances it

In a series of experiments, we examined the effect of requiring subjects to attend to distractors in a test of negative priming. This was accomplished by using a referent size-selection task in which subjects were instructed to name the larger animal and to ignore the smaller animal in a word pair. The result was a quadrupling of the standard negative priming effect, suggesting that negative priming not only occurs for attended distractors, it is actually enhanced. We demonstrated that this enhancement of the effect was not due solely to increased latencies in the referent size-selection task, because neither decreasing base response times in other referent size-selection tasks nor increasing base response times in typical color-selection tasks substantially affected the respective negative priming effects. Although these findings can be accommodated within current theories of negative priming, they challenge the basic assumption that the negative priming effect arises because the critical item was ignored or not attended to on the prime trial.

The influence of attention at encoding on direct and indirect remembering

The relation between attention at encoding and direct (i.e., recognition) versus indirect (i.e., rapid reading) remembering was investigated. In Experiments 1 and 2, color of print indicated whether to read an individual word aloud or to ignore it. This attentional manipulation reduced direct but not indirect remembering for the ignored words relative to the attended words. Apparently direct remembering is extremely dependent on attention at encoding. In Experiment 3, however, presenting two words simultaneously at study, with color now signifying which word to read and which to ignore, eliminated this dissociative effect of attention. Ignored words were not remembered on either test, although attended words were remembered well on both. Mere exposure is not sufficient to produce indirect remembering: Stimuli must be attended. Ignoring one stimulus in favor of processing another stimulus that is simultaneously presented and equally salient may prevent even the minimal attentional requirements of indirect remembering from being met, let alone the more stringent requirements of direct remembering.

Memory and confidence in memory judgements among individuals with obsessive compulsive disorder and non-clinical controls

The present study investigated episodic memory functioning in: (1) obsessive compulsive disorder (OCD) patients with primarily checking symptoms (i.e. checkers); (2) OCD patients without checking symptoms (i.e. non-checkers); and (3) non-clinical control participants. On a measure of recall, all groups were statistically equivalent with respect to the proportion of words correctly recalled. Using a recognition measure, checkers were unimpaired in episodic memory, as compared to non-checkers and non-clinical controls. However, relative to the other groups, patients with checking symptoms showed decreased confidence in their correct and incorrect recognition memory judgements, according to their item-by-item self-report confidence ratings. When checkers correctly identified previously seen words, they were also slower to respond than were the other groups, supporting the view that they were less confident in their memory judgments relative to the other groups, which did not differ on this measure. The results of the present study suggest that OCD checking is not related to memory impairments per se but rather that checking in OCD is a symptom of decreased confidence in memory.

Measles in the 1980s

We detail aspects of measles immunization programmes in several countries. Live measles vaccine has been available in Australia for 16 years, yet, in 1981, there were outbreaks of measles in the State of New South Wales (population 5 200 000) which led to 2200 admissions to hospital and five deaths. In response to complaints of "vaccine failure", a survey determined that 22.5% of children with measles seen by general practitioners and 10.3% of those admitted to hospitals had been previously immunized. There was no evidence of waning immunity, and noparticular batch of vaccine was implicated. The vaccine failures are attributed in part to failure of seroconversion in some recipients when immunized at 12 months of age as a result of interference by transplacentally acquired antibodies. As more of the susceptible population is vaccinated, there will be fewer cases of measles, but among these cases will be an increasing proportion of cases occurring in previously vaccinated individuals. The equation to calculate this expected proportion of "vaccine failures" is given. We support the measures to increase immunization compliance.