Anticonvulsants in the treatment of aggression in the demented elderly: an update

Gabapentin and pregabalin to treat aggressivity in dementia: a systematic review and illustrative case report

AIMS

The prevalence of dementia is rising as life expectancy increases globally. Behavioural and psychological symptoms of dementia (BPSD), including agitation and aggression, are common, presenting a challenge to clinicians and caregivers.

METHODS

Following PRISMA guidelines, we systematically reviewed evidence for gabapentin and pregabalin against BPSD symptoms of agitation or aggression in any dementia, using six databases (Pubmed, CINHL, PsychINFO, HealthStar, Embase, and Web of Science). Complementing this formal systematic review, an illustrative case of a patient with BPSD in mixed Alzheimer's/vascular dementia, who appeared to derive benefits in terms of symptom control and functioning from the introduction of gabapentin titrated up to 3600 mg day^-1 alongside other interventions, is presented.

RESULTS

Twenty-four relevant articles were identified in the systematic review. There were no randomized trials. Fifteen papers were original case series/case reports of patients treated with these compounds, encompassing 87 patients given gabapentin and six given pregabalin. In 12 of 15 papers, drug treatment was effective in the majority of cases. The remaining nine papers were solely reviews, of which two were described as systematic but predated PRISMA guidelines. Preliminary low-grade evidence based on case series and case reviews suggests possible benefit of gabapentin and pregabalin in patients with BPSD in Alzheimer's disease. These benefits cannot be confirmed until well-powered randomized controlled trials are undertaken. Evidence in frontotemporal dementia is lacking.

CONCLUSION

Gabapentin and pregabalin could be considered for BPSD when medications having stronger evidence bases (risperidone, other antipsychotics, carbamazepine and citalopram) have been ineffective or present unacceptable risks of adverse outcomes.

Epigenetic interventions for epileptogenesis: A new frontier for curing epilepsy

This article highlights the emerging therapeutic potential of specific epigenetic modulators as promising antiepileptogenic or disease-modifying agents for curing epilepsy. Currently, there is an unmet need for antiepileptogenic agents that truly prevent the development of epilepsy in people at risk. There is strong evidence that epigenetic signaling, which exerts high fidelity regulation of gene expression, plays a crucial role in the pathophysiology of epileptogenesis and chronic epilepsy. These modifications are not hard-wired into the genome and are constantly reprogrammed by environmental influences. The potential epigenetic mechanisms, including histone modifications, DNA methylation, microRNA-based transcriptional control, and bromodomain reading activity, can drastically alter the neuronal gene expression profile by exerting their summative effects in a coordinated fashion. Such an epigenetic intervention appears more rational strategy for preventing epilepsy because it targets the primary pathway that initially triggers the numerous downstream cellular and molecular events mediating epileptogenesis. Among currently approved epigenetic drugs, the majority are anticancer drugs with well-established profiles in clinical trials and practice. Evidence from preclinical studies supports the premise that these drugs may be applied to a wide range of brain disorders. Targeting histone deacetylation by inhibiting histone deacetylase enzymes appears to be one promising epigenetic therapy since certain inhibitors have been shown to prevent epileptogenesis in animal models. However, developing neuronal specific epigenetic modulators requires rational, pathophysiology-based optimization to efficiently intercept the upstream pathways in epileptogenesis. Overall, epigenetic agents have been well positioned as new frontier tools towards the national goal of curing epilepsy.

The efficacy and safety of newer anticonvulsants in patients with dementia

Anticonvulsants are a class of medications that have received considerable interest as possible treatments in patients with behavioural disturbances in dementia. The role of these medications for such a use remains controversial. The current paper reviews the published evidence surrounding the safety and efficacy (i.e. as a behavioural and cognitive treatment) of newer anticonvulsants in patients with dementia. A MEDLINE, International Pharmaceutical Abstracts, PsycINFO and clinicaltrials.gov search through to December 2011 was conducted for anticonvulsants that have received regulatory approval since 1996. Studies reporting behavioural or cognitive outcomes in patients with dementia were included. Nine trials involving only four medications met selection criteria and were included: levetiracetam (n = 4), oxcarbazepine (n = 1), topiramate (n = 2) and zonisamide (n = 2). Levetiracetam may have a role in the treatment of behavioural symptoms in dementia but study limitations substantially hinder the strength of such a recommendation. Oxcarbazepine and topiramate, based on limited data, do not appear to be effective treatments of behavioural symptoms in dementia. A lack of trials do not allow for conclusions to be made regarding zonisamide. From a cognitive standpoint, levetiracetam was the anticonvulsant most examined in patients with dementia, it appears to have less deleterious effects than some anticonvulsants. Limited data are available on the safety of these medications in elderly patients; however, studies completed thus far have demonstrated some adverse events that are more common or problematic with the use of these drugs in this patient population (i.e. somnolence, dizziness, hyponatraemia, weight loss).

Dosing of valproate in an elderly population with dementia: Evaluation of discontinuations and dose reductions

It is estimated that more than half of elderly patients with dementia will develop some degree of behavioral and psychological symptoms of dementia (BPSD). BPSD is associated with significant morbidity, rapid functional decline, and psychiatric hospitalization, and there are currently no medications approved by the Food and Drug Administration (FDA) for its treatment. One treatment option that has been evaluated is the antiepileptic drug valproate. This retrospective medical record review evaluated the tolerability of valproate in elderly patients with dementia. A total of 62 patients met inclusion criteria for this review, which sought to determine whether there was an association either between the initial valproate dose and discontinuation or dose reduction (DCDR) or the maximum valproate dose achieved and DCDR. Both the total daily dose and total daily dose in mg/kg were assessed. For both the maximum daily dose (OR 1.0; 95% CI 0.99, 1.01) and maximum daily mg/kg dose (OR =1.15; 95% CI 0.92, 1.49) there was also no association with DCDR. There was no associated risk of DCDR when evaluating initial daily doses (OR: 1.0; 95% CI: 0.99 – 1.01). However, an association between DCDR and initial daily mg/kg dose was found (OR: 1.92; 95% CI: 1.11–4.02). For both the initial dose and initial mg/kg dose model, African Americans were associated with the need for DCDR (OR 20.75; 95% CI: 1.77–660). Results from this study suggest that higher initial starting doses based on weight may lead to higher rates of side effects necessitating a discontinuation or dose reduction; however, large trials are needed to confirm these results.

Mood stabilizers for the treatment of behavioral and psychological symptoms of dementia: an update review

Behavioral and psychological symptoms of dementia (BPSD) are common and debilitating problems, but current treatments are limited. Antipsychotic agents show some efficacy on BPSD, but their use is limited by the associated risk of cerebrovascular events and mortality. Reports have shown the efficacy of mood stabilizers on BPSD, but systemic reviews on this issue are scant. This article aims to review studies of the efficacy of mood stabilizers on BPSD, and the quality of the available evidence. We searched for articles published in English during the period 1990 to 2010 and included in the PubMed database that concerned treatment of BPSD with mood stabilizers, such as carbamazepine, valproate, gabapentin, topiramate, lamotrigine, oxcarbazepine and lithium. The quality of the studies was assessed by considering the trial designs, analyses, subjects and results. We found one meta-analysis and three randomized controlled trials (RCTs) supporting the efficacy of carbamazepine in managing global BPSD, particularly aggression and hostility. With regard to valproate, current evidence from one meta-analysis and five RCTs did not strongly support its efficacy for global BPSD, including agitation and aggression. Only open trials or case series showed some efficacy of gabapentin, topiramate and lamotrigine in controlling BPSD. The single RCT investigating the effect of oxcarbazepine on agitation and aggression showed negative results. Case series reports on lithium tended to show it to be ineffective. Thus far, among mood stabilizers, carbamazepine has the most robust evidence of efficacy on BPSD. More RCTs are needed to strengthen evidence regarding the efficacy of gabapentin, topiramate and lamotrigine. Valproate, oxcarbazepine and lithium showed low or no evidence of efficacy. Large and well designed RCTs focusing on specific symptoms of BPSD are needed to deal with the issue.

Citalopram for agitation in Alzheimer's disease: design and methods

BACKGROUND

Agitation is one of the most common neuropsychiatric symptoms of Alzheimer's disease (AD), and is associated with serious adverse consequences for patients and caregivers. Evidence-supported treatment options for agitation are limited. The citalopram for agitation in Alzheimer's disease (CitAD) study was designed to evaluate the potential of citalopram to ameliorate these symptoms.

METHODS

CitAD is a randomized, double-masked, placebo-controlled multicenter clinical trial, with two parallel treatment groups assigned in a 1:1 ratio and randomization stratified by clinical center. The study included eight recruiting clinical centers, a chair's office, and a coordinating center located in university settings in the United States and Canada. A total of 200 individuals having probable AD with clinically significant agitation and without major depression were recruited for this study. Patients were randomized to receive citalopram (target dose of 30 mg/d) or matching placebo. Caregivers of patients in both treatment groups received a structured psychosocial therapy. Agitation was compared between treatment groups using the NeuroBehavioral Rating Scale and the AD Cooperative Study- Clinical Global Impression of Change, which are the primary outcomes. Functional performance, cognition, caregiver distress, and rates of adverse and serious adverse events were also measured.

CONCLUSION

The authors believe the design elements in CitAD are important features to be included in trials assessing the safety and efficacy of psychotropic medications for clinically significant agitation in AD.

Modulation of ion channels in clinical psychopharmacology: adults and younger people

This review focuses on the use of Na(+), Ca(2+) and Cl(-) channel modulators in psychiatric disease. Drugs that modulate ion channels have been used in psychiatry for more than a century, and in this review we critically evaluate clinical research that reports the therapeutic effects of drugs acting on GABA(A), voltage-gated Na(+) and voltage-gated Ca(2+) channels in pediatric and adult patients. As in other fields, the evidence underpinning the use of medicines in younger people is far less robust than for adults. In addition, we discuss some current developments and highlight clinical disorders in which current molecules could be further tested. Notable success stories, such as benzodiazepines (in sleep and anxiety disorders) and antiepileptics (in bipolar disorder), have been the result of serendipitous discoveries or refinements of serendipitous discoveries, as in all other major treatments in psychiatry. Genomic, high-throughput screening and molecular pharmacology discoveries may, however, guide further developments in the future. This could include increased research in promising targets that have been perceived as commercially risky, such as selective α-subunit GABA(A) receptors.