Identifying and treating patients with suboptimal responses

Multiple sclerosis (MS) is an immune-mediated neurologic disease in which acute inflammatory events early in the disease course contribute to subsequent neurologic disability. The early relapsing inflammatory phase is followed by a progressive degenerative phase in which the frequency of acute inflammatory attacks diminishes but progressive loss of neurologic function continues. Current immune therapies are most effective in suppressing the acute inflammatory events that characterize the earlier stages of disease. Optimal suppression of these inflammatory events is likely to have the best potential for delaying or preventing loss of axons and decline in neurologic function. In view of these considerations, and because MS is a heterogeneous disease and response to disease-modifying agents (DMA) varies across individuals, it is important to identify suboptimal responders as early as possible to allow therapeutic modification while the opportunity to avert future loss of function remains. At present, no criteria for identifying suboptimal responders have been validated. In January 2004, a group of neurologists from 16 MS centers in the United States met to develop a consensus on criteria for defining suboptimal response for use in compelling clinical situations and to prompt clinical studies to validate the efficacy of these criteria. Consensus criteria included relapse rates of either 1/year or unchanged from pretreatment rates, incomplete recovery from multiple attacks, evolution of polyregional neurologic involvement, recurrent brainstem or spinal cord lesions, and cumulative loss of neurologic function sufficient to disrupt daily activities. The panel then considered the use of mitoxantrone for patients with worsening MS and a suboptimal response to DMA therapy.

Effects of treatment with lovastatin and pravastatin on daytime cognitive performance

The HMG-CoA reductase inhibitors lovastatin and pravastatin have both proven to be effective and well tolerated in the treatment of hypercholesterolemia. To evaluate whether lovastatin or pravastatin might affect daytime cognitive function, a double-blind, placebo-controlled, two-period, incomplete block, crossover study was performed in 36 patients (24 per treatment) with primary hypercholesterolemia. Patients received placebo, lovastatin (40 mg), or pravastatin (40 mg) for 4 weeks. Following a 1-week washout period, patients were crossed over to either lovastatin, pravastatin, or placebo for an additional 4 weeks. Mental performance tests (digit symbol substitution, choice reaction time, auditory vigilance, selective reminding word recall, finger tapping), visual analogue rating scales, and the Profile of Mood States were administered before test drug administration and after 2 and 4 weeks of each treatment. After 4 weeks, no statistically significant differences between treatments in changes from baseline were observed on any parameter with the exception of digit symbol substitution, for which lovastatin and pravastatin were both significantly better than placebo but did not differ from each other. Low-density lipoprotein cholesterol was reduced 38% by lovastatin and 30% by pravastatin. In summary, neither of these chemically distinct HMG-CoA reductase inhibitors impaired daytime cognitive performance after 4 weeks of treatment in patients with primary hypercholesterolemia.