Dystonic reactions are adverse extrapyramidal side effects and are common to antipsychotics, antiemetics, and a variety of other drugs. Rivastigmine, an anticholinesterase of carbamate variety, is well tolerated. A case of acute dystonic reaction with rivastigmine patch is being reported.

The occurrence of mania in the geriatric population is rare. Furthermore, there were only six case reports of elderly patients with secondary mania resulting from treatment with cholinesterase inhibitors. In all cases, patients had a prior psychiatric history. We report the case of an elderly patient with no prior history of psychiatric or other organic disorders who experienced first episode mania following treatment with rivastigmine. We discuss the possible mechanism of mania in this patient.

Background: Cholinesterase inhibitors (ChEIs) represent the mainstay of symptomatic treatment in Alzheimer's disease. Three medications belonging to this class are presently widely available. These agents differ in their individual mechanisms of action and pharmacokinetic properties. Switching ChEIs can be a reasonable option in cases of intolerance or lack of clinical benefit.

Methods: A systematic literature search of switching ChEIs was conducted, and all studies specifically evaluating this issue were identified. Published consensus guidelines were also searched for recommendations on ChEI switching.

Results: Eight clinical studies are summarized and discussed. All of these studies are open-label or retrospective and they cannot be readily compared because of heterogeneity in design, number of patients, agents used, and endpoints. Switching in most of these studies was done for both “lack of benefit” or “loss of response” after up to 29 months of treatment. Nevertheless, the majority of studies did not include individuals switched for lack of response after several years of treatment. Lack of satisfactory response or intolerance with the initial agent was not predictive of similar results with the second agent.

Conclusions: In light of these findings, we propose the following practical approach to switching ChEIs: (1) in the case of intolerance, switching to a second agent should be done only after the complete resolution of side-effects following discontinuation of the initial agent; (2) in the case of lack of efficacy, switching can be done overnight, with a quicker titration scheme thereafter; (3) switching ChEIs is not recommended in individuals who show loss of benefit several years after initiation of treatment.

Background: This study sought to examine the trends in the prescribing of subsidized and unsubsidized cognition enhancing drugs (CEDs) in Australia over five years from 2002 to 2007. Subsidized cholinesterase inhibitor medication could be prescribed to people with mild to moderate Alzheimer's disease (AD) once a specialist physician had confirmed this diagnosis. Memantine was available for use in moderately severe AD but not subsidized.

Methods: We analyzed the Medicare Australia and Drug Utilisation Sub-Committee databases for CED prescription data, 2002–2007, by gender, age and prescriber class. Aggregated prescription data for each medication were converted to defined daily doses (DDD) per 1000 persons per day using national census data.

Results: There were 1,583,667 CED prescriptions dispensed during the study period. CED use increased 58% from 0.91 to 1.56 DDD/1000 persons/day between 2002 and 2007. Peak use was in those aged 85–89 years. Age-adjusted utilization was slightly higher in females than males. Donepezil was the most widely used CED (66%), followed by galantamine (27%) then memantine (4%). General practitioners prescribed the majority of CEDs. Geriatricians exhibited a greater preference for galantamine than other prescribers. CED dispensing peaked towards the end of each calendar year, reflecting stockpiling by patients under the influence of a federal safety net subsidy.

Conclusions: Despite subsidized access to CEDs in Australia, only a minority of people with AD was prescribed these drugs during the period of the study. It is likely that the combination of complex prescribing rules and negative perceptions about efficacy or cost-effectiveness might have contributed to these findings.

ABSTRACT

There has been continuous progress in neurotherapeutics and neuropsychopharmacology in the past year. Notable are the reports of successful preliminary disease-modifying trials in Niemann-Pick disease and Friedreich's ataxia. Progress also has been made in treatment of migraine, stroke, epilepsy, multiple sclerosis, traumatic brain injury, and pain. Biomarkers are increasingly used to establish proof of pharmacology including measures of cerebrospinal fluid constituents and brain changes on magnetic resonance imaging. There is an increasing diversity of patient populations participating in clinical trials, including pediatric migraine and traumatic brain injury.

Alzheimer's disease (AD) is characterized by deterioration in the ability to perform activities of daily living (ADL) in addition to loss of cognitive function and behavioral changes. This decline in day-to-day functioning is increasingly recognized as a source of considerable social, health, and economic costs. Inability to perform ADL results in growing caregiver burden and may lead to the eventual need for alternative care or nursing home placement. The measurement of ADL, which enables monitoring of the effectiveness of therapeutic interventions, can be performed using a number of inventories including the Progressive Deterioration Scale (PDS), the Disability Assessment for Dementia (DAD), and the Alzheimer Disease Cooperative Study ADL (ADCS/ADL) assessment scale. Clinical studies using these and other scales have indicated that cholinesterase (ChE) inhibitors offer an effective approach to treating the functional decline of AD. Donepezil, rivastigmine, and galantamine have been shown in some studies to prevent or slow decline in ADL over treatment periods of one to two years. For instance, in a 24-week study in subjects with moderate to severe AD, donepezil-treated patients remained stable compared with the placebo-treated patients. Rivastigmine has shown improvement or stabilization of PDS scores in patients with mild to moderate disease following 26 weeks of treatment and slowed deterioration in patients with more severe disease. Evidence to date suggests that these agents may not be equally effective at slowing or stabilizing loss in ADL over time and that these differences may reflect differences in pharmacology. In addition to inhibition of acetylcholinesterase (AChE), these compounds have other putative differences in mechanisms of action. Galantamine allosterically modulates the nicotinic receptor and may prevent the loss of ADL. Rivastigmine robustly inhibits butyrylcholinesterase in addition to AChE and therefore acts as a dual ChE inhibitor. Comparative studies evaluating the differential effects of these ChE inhibitors on ADL are awaited.

This review provides an overview of the three most widely used cholinesterase (ChE) inhibitors: donepezil, rivastigmine, and galantamine. Differences in pharmacologic profiles will be discussed, and consideration will be given to how such differences may relate to and influence the clinical efficacy and tolerability of the various agents. In addition to providing cognitive benefits in patients with Alzheimer's disease (AD), growing clinical evidence also suggests that ChE inhibitors can produce favorable and clinically relevant effects on neuropsychiatric/behavioral disturbances and activities of daily living. Furthermore, recent data indicate that these agents may be effective at all levels of disease severity and for all rates of disease progression. The clinical utility of ChE inhibitors in a wider spectrum of dementias which share a common cholinergic deficit, such as Lewy body dementia, Parkinson's disease dementia, and vascular dementia, is currently under investigation. Beyond symptomatic relief, data suggest that ChE inhibitors may also slow the underlying disease process. As clinical and research experience with these agents continues to accumulate, the differences in their effects will become more apparent and will help physicians tailor ChE inhibition treatment to the needs of the individual patient.

Acetylcholinesterase (AChE) predominates in the healthy brain, with butyrylcholinesterase (BuChE) considered to play a minor role in regulating brain acetylcholine (ACh) levels. However, BuChE activity progressively increases in patients with Alzheimer's disease (AD), while AChE activity remains unchanged or declines. Both enzymes therefore represent legitimate therapeutic targets for ameliorating the cholinergic deficit considered to be responsible for the declines in cognitive, behavioral and global functioning characteristic of AD. The two enzymes differ in substrate specificity, kinetics and activity in different brain regions. Experimental evidence from the use of agents with enhanced selectivity for BuChE (cymserine analogues, MF-8622) and the dual inhibitor of both AChE and BuChE, rivastigmine, indicates potential therapeutic benefits of inhibiting both AChE and BuChE in AD and related dementias. Recent evidence suggests that both AChE and BuChE may have roles in the aetiology and progression of AD beyond regulation of synaptic ACh levels. The development of specific BuChE inhibitors and further experience with the dual enzyme inhibitor rivastigmine will improve understanding of the aetiology of AD and should lead to a wider variety of potent treatment options.

Vascular dementia (VaD), like Alzheimer's disease (AD), is associated with cholinergic deficits. Rivastigmine provides sustained, brain-selective inhibition of acetylcholinesterase and butyrylcholinesterase. Preliminary data suggest that rivastigmine may provide significant benefits in patients with AD and cerebrovascular disease (mixed dementia), and in patients with VaD. Open-label rivastigmine treatment has been associated with improved cognitive and functional abilities, behavioral symptoms, and reduced caregiver stress in a small pilot study in these patients. Larger, prospective, double-blind studies of rivastigmine in patients with VaD are under way. These studies will confirm whether rivastigmine is an efficacious treatment option for a range of patients for whom, until now, there have been few symptomatic therapies.

Background: Alzheimer's disease (AD) places a significant burden on health care systems worldwide. As new treatments are developed, their cost-effectiveness is often assessed to help health care professionals make informed decisions. In addition to the more common practice of assessing direct medical costs, indirect costs, including time spent in caregiving, should be evaluated. Methods: This study examined the potential effects of the dual cholinesterase inhibitor rivastigmine (Exelon) on caregivers of patients with AD. Results from two 26-week, placebo-controlled trials have demonstrated the clinically relevant and statistically significant efficacy of rivastigmine (6–12 mg/day) compared to placebo, on cognition, activities of daily living, and global functioning. By delaying progression of AD, significant savings in caregiver burden are anticipated, as measured by time spent caregiving and its related costs. Data collected in a prospective, observational study of AD patients and their caregivers were used to establish the relationship between disease severity (based on Mini-Mental State Examination [MMSE] score) and time spent caregiving (according to the 5-item Caregivers Activity Survery score). A significant correlation was observed between the two scores (N = 43, r = −.56, p < .0001), demonstrating that more time for supervision from caregivers is required as the disease progresses. This finding was used to estimate the reduced caregiver burden resulting from the delay in disease progression that was demonstrated with use of rivastigmine. Results: Over a 2-year period, the reduction in time spent in caregiving reached 691 hours for caregivers of patients with mild AD (MMSE score 21–30), resulting in a total savings of approximately $11,253. Treatment of patients with moderately severe AD was also evaluated. The trend was similar but the impact was less, suggesting an economic benefit to early therapy. Conclusion: Early diagnosis and a pharmacologic intervention that allows the patients to remain at home longer by delaying disease progression would have a beneficial impact on patients, caregivers, and payers, and should therefore be encouraged through initiatives designed to identify and treat patients early in the course of disease.