Strategies for optimizing antiepileptic drug therapy in elderly people

Recent Hospitalization and Initiation of Antiepileptics Among Persons With Alzheimer's Disease

OBJECTIVES

Antiepileptic drugs (AEDs) are frequently prescribed for persons with Alzheimer's disease (AD), but little is known on factors associated with AED initiation in this population. We investigated whether recent hospitalization is associated with AED initiation in persons with AD.

DESIGN

Nested case-control study in the nationwide register-based Medication use and Alzheimer's disease (MEDALZ) cohort.

PARTICIPANTS AND SETTINGS

The MEDALZ cohort includes 70,718 persons diagnosed with AD during 2005-2011 in Finland. Altogether 6814 AED initiators and 6814 age-, sex-, and time since AD diagnosis-matched noninitiators were included in this study. Matching date was the date of AED initiation.

METHODS

AED purchases were identified from the Prescription Register and hospitalizations from the Care Register for Health Care. Recent hospitalization was defined as hospitalization ending within 2 weeks before the matching date. Association between recent hospitalization and AED initiation was assessed with conditional logistic regression.

RESULTS

The most frequently initiated AEDs were pregabalin (42.9%) and valproic acid (32.2%). A bigger proportion of AED initiators (36.9%) than noninitiators (5.3%) were recently hospitalized [odds ratio (OR) 10.5, 95% CI 9.22-11.9]. Dementia was the most frequent discharge diagnosis among AED initiators (29.1%) and noninitiators (27.9%). Among AED initiators, the next most frequent diagnosis was epilepsy (20.6%). Musculoskeletal diagnoses and use of analgesics including opioids was more common among gabapentinoid initiators compared with other AED initiators.

CONCLUSIONS AND IMPLICATIONS

Recent hospitalization was significantly related to AED initiation. Initiations of AED might have been related to common symptoms in persons with AD like neuropathic pain, epilepsy, and neuropsychiatric symptoms.

Serum monitoring of carbamazepine in patients with epilepsy and clinical implications

Carbamazepine is a drug with a narrow therapeutic range that requires clinical monitoring, since its toxic effects are not easily predictable, and the therapeutic level can vary. Our study aimed to monitor the serum level and determine the concentration/dose relationship of carbamazepine in people with epilepsy, analyzing its clinical implication. It is observed that 90.48% of the study volunteers present serum level values (4.3–10.4 mg/L) within the therapeutic range (4–12 mg/L); 7.14% present supratherapeutic levels (12.7–14.4 mg/L), 2.38% subtherapeutic (0.93 mg/L). The findings indicate a negative correlation (r = -0.616; r2 = 0.379; p = 0.001), between the dose (mg/day) and the dose ratio (mg/L/mg/day); and a positive correlation (r = 0.544; r2 = 0.296; p = 0.002), between the dose (mg/day)-serum concentration (mg/L). ANOVA and Tukey’s test mean difference is significant (p<0.05). It is concluded that there is a positive and significant linear correlation between daily doses and serum carbamazepine concentrations, which should be considered to individualize the dose and optimize clinical results.

Antiepileptic Drugs and Accumulation of Hospital Days Among Persons With Alzheimer's Disease

OBJECTIVES

To compare the accumulation of hospital days between initiators and noninitiators of antiepileptic drugs (AEDs) among persons with Alzheimer's disease (AD).

DESIGN

Exposure-matched cohort study.

SETTING AND PARTICIPANTS

Persons newly diagnosed with AD in 2005-2011 (n = 70,718) and initiating AED use identified from Finnish health care registers. For each AED initiator, 1 noninitiator matched on age, sex, and time since AD diagnosis was selected. Persons with epilepsy were excluded from the study.

METHODS

Association between AED initiation or use of individual AEDs and accumulation of hospital days during a 2-year follow-up was assessed using negative binomial model.

RESULTS

AED initiators (n = 4432) were hospitalized on average for 43.7 (SD: 88.3) days and matched noninitiators for 32.2 (SD: 71.3) days during the 2-year follow-up. Altogether, 27.3% of the AED initiators and 35.6% of the noninitiators had no hospital days during the study period. Number of accumulated hospital days during the follow-up was 31% higher [adjusted incidence rate ratio (aIRR): 1.31, 95% confidence interval (CI): 1.19-1.43] among AED initiators than the noninitiators. Hospital days due to diseases of the nervous system excluding dementia (aIRR: 2.72, 95% CI: 1.72-4.31), musculoskeletal system (aIRR: 2.49, 95% CI: 1.73-3.58), respiratory system (aIRR: 1.89, 95% CI: 1.47-2.43), and mental and behavioral disorders excluding dementia (aIRR: 1.96, 95% CI: 1.02-3.79) were more common among the AED initiators than noninitiators. Among pregabalin (aIRR: 0.65, 95% CI: 0.56-0.77), gabapentin (aIRR: 0.66, 95% CI: 0.49-0.88), and clonazepam (aIRR: 0.73, 95% CI: 0.55-0.96) initiators, the number of accumulated hospital days was 27% to 35% lower than the days accumulated among the initiators of valproic acid.

CONCLUSIONS AND IMPLICATIONS

AED initiators had more hospital days than noninitiators. Pregabalin and gabapentin were associated with a lower number of hospital days than valproic acid. Further research is needed on the reasons for these findings.

Disease Specific Aspects of Malnutrition in Neurogeriatric Patients

Malnutrition in elderly patients is a common condition. Nevertheless, there is evidence on specific risk factors and problems of malnutrition in geriatric patients with neurological diseases. In this review, we summarize recent knowledge on malnutrition in different neurological diseases with a focus on elderly patients. This overview also provides strategies for a more specific and profound assessment of neurogeriatric patients to improve identification and treatment of malnutrition. Early and consequent treatment of malnutrition can lead to a decreased progression of the neurological disease and to a better quality of life in geriatric patients.

Is herpes zoster an additional complication in old age alongside comorbidity and multiple medications? Results of the post hoc analysis of the 12-month longitudinal prospective observational ARIZONA cohort study

OBJECTIVES

To examine the burden of comorbidity, polypharmacy and herpes zoster (HZ), an infectious disease, and its main complication post-herpetic neuralgia (PHN) in young (50-70 years of age: 70-) and old (≥ 70 years of age: 70+) patients.

DESIGN

Post hoc analysis of the results of the 12-month longitudinal prospective multicentre observational ARIZONA cohort study.

SETTINGS AND PARTICIPANTS

The study took place in primary care in France from 20 November 2006 to 12 September 2008. Overall, 644 general practitioners (GPs) collected data from 1358 patients aged 50 years or more with acute eruptive HZ.

OUTCOME MEASURES

Presence of HZ-related pain or PHN (pain persisting >3 months) was documented at day 0 and at months 3, 6, and 12. To investigate HZ and PHN burden, pain, quality of life (QoL) and mood were self-assessed using validated questionnaires (Zoster Brief Pain Inventory, 12-item Short-Form health survey and Hospital Anxiety and Depression Scale, respectively).

RESULTS

As compared with younger patients, older patients more frequently presented with comorbidities, more frequently took analgesics and had poorer response on all questionnaires, indicating greater burden, at inclusion. Analgesics were more frequently prescribed to relieve acute pain or PHN in 70+ than 70- patients. Despite higher levels of medication prescription, poorer pain relief and poorer response to all questionnaires were reported in 70+ than 70- patients.

CONCLUSIONS

Occurrence of HZ and progression to PHN adds extra burden on top of pharmacological treatment and impaired quality of life, especially in older patients who already have health problems to cope with in everyday life.

Effect of topiramate monotherapy on height in newly diagnosed children with epilepsy

We conducted a post hoc assessment of the effect of ≥6 months of topiramate monotherapy on height in pediatric patients with newly diagnosed partial-onset seizure. Data on height measured nonsystematically up to 4 years from two randomized, double-blind studies and their open-label extensions were combined and converted to z scores and percentiles by patient's sex and age. Height velocity values (centimeters per year) and the associated z scores were computed for each postbaseline year using normative data. Median height velocity (centimeters per year) values and the associated z scores for patients ages 6-9 years were, year 1: 4.7 (-0.91); year 2: 4.2 (-1.62); year 3: 4.5 (-1.87); and for patients ages 10-15 years were, year 1: 4.0 (-0.76); year 2: 2.8 (-1.34); year 3: 3.1 (-0.74). There was a significant correlation between height velocity z score and change from baseline in height z score (r = 0.94 [n = 117]; P < 0.0001). Patient's bicarbonate status (low was defined as two postbaseline serum bicarbonate values <20 mmol/L) and sex had no effect on height velocity. In both age groups, continued growth was observed; however, the growth rate was slower than expected compared with a matched normal population from years 1 to 2 and showed minimal recovery from years 2 to 3.

Clinical practice: the treatment of acute convulsive seizures in children

An adequate early treatment of a long-lasting convulsive seizure is critical in reducing potential morbidity, and in particular, brain damage. In pre-hospital settings the use of benzodiazepines should become standard. Nowadays, rectal diazepam is used frequently, but midazoloam and lorazepam are becoming more popular, both being given either intranasally or orally. The buccal route is to be preferred because of its easy use and high efficacy. A generally accepted policy for early treatment of convulsive seizures is a crucial issue in the elaboration of an overall treatment plan for the child with epilepsy. Such a plan should include instruction and education of the parents and the caregivers surrounding the child.

Best clinical and research practice in epilepsy of older people: Focus on antiepileptic drug adherence

Few studies have examined the issues that are specific to the older person with epilepsy, a population of increasing prominence in epilepsy management. Our understanding of the impact of epilepsy in the older person is based predominantly on what is inferred from studies of younger adults. Consequently, there is relatively little documented about the impact of epilepsy on the everyday lives of older people. In this article, we focus on adherence and its consequences for the physical, social, and psychological well-being of the older person. A number of strategies are proposed to improve adherence, including patient education through better communication between physician and patient; simplification of the medical regime; and use of extended-release formulations. This issue highlights that to ameliorate the impact of epilepsy for the older person with epilepsy, a greater understanding is required so that appropriate interventions can be tailored.

Prevalence and cost of nonadherence to antiepileptic drugs in elderly patients with epilepsy

Retrospective insurance claims from the United States were analyzed to assess nonadherence to antiepileptic drugs (AEDs) and the association between AED nonadherence, seizures, and health care costs in elderly persons with epilepsy. Inclusion criteria were: age 65, epilepsy diagnosis between 1 January 2000 and 31 June 2006, 2 AED prescriptions, and insurance enrollment for 6 months pre- and 12 months post-AED initiation. Adherence was evaluated using the medication possession ratio (MPR), with MPR<0.8 defining nonadherence. Per-patient outcomes were evaluated over 12 months post-AED initiation. Of 1278 patients identified, 41% were nonadherent. Seizure, defined by epilepsy-related inpatient or emergency department admission, occurred in 12.1% of nonadherers versus 8.2% of adherers (P=0.0212). Nonadherers had higher inpatient (+$872, P=0.001), emergency department (+$143, P=0.0008), other outpatient ancillary (+$1741, P=0.0081), and total health care (+$2674, P=0.0059) costs. AED adherence among elderly patients with epilepsy is suboptimal and associated with increased seizures and health care costs.

Lamotrigine therapy in elderly patients with epilepsy, bipolar disorder or dementia

INTRODUCTION

In spite of circumstances that precipitate high use of anticonvulsants in geriatric populations, there is a paucity of data on the use of antiepileptic drugs in elderly patients with psychiatric and neurological disorders.

METHODS

Reports of lamotrigine therapy in elderly patients with epilepsy, bipolar disorder (BD), or dementia were identified by conducting an electronic search of major publication databases. Abstracts and presentations from professional meetings were searched as were the bibliographies of relevant articles.

RESULTS

Fourteen reports were identified, and included well-controlled prospective trials, retrospective analyses, and case reports of lamotrigine treatment. Controlled trials in elderly patients with epilepsy demonstrate efficacy and tolerability comparable to gabapentin. Improvement in bipolar depressive symptoms, improvement in core manic symptoms, and delay in mood relapse was reported in geriatric patients with BD. Preliminary case studies in patients with dementia note improvement in cognition and symptoms of agitation and depression.

CONCLUSION

Review of the available literature suggests lamotrigine is effective and well tolerated in elderly patients with epilepsy and relatively well-tolerated and may be effective in delaying mood relapse, particularly in the depressive pole, in patients with BD. While very limited literature suggests that lamotrigine may be effective and relatively well-tolerated in patients with dementia, further studies are needed.

Antiepileptic drugs and bone metabolism

Anti-epileptic medications encompass a wide range of drugs including anticonvulsants, benzodiazepines, enzyme inducers or inhibitors, with a variety effects, including induction of cytochrome P450 and other enzyme, which may lead to catabolism of vitamin D and hypocalcemia and other effects that may significantly effect the risk for low bone mass and fractures. With the current estimates of 50 million people worldwide with epilepsy together with the rapid increase in utilization of these medications for other indications, bone disease associated with the use of anti-epileptic medications is emerging as a serious health threat for millions of people. Nevertheless, it usually goes unrecognized and untreated. In this review we discuss the pathophysiologic mechanisms of bone disease associated with anti-epileptic use, including effect of anti-epileptic agents on bone turnover and fracture risk, highlighting various strategies for prevention of bone loss and associated fractures a rapidly increasing vulnerable population.

Antiepileptic drug use and epileptic seizures in elderly nursing home residents: a survey in the province of Pavia, Northern Italy

Some surveys indicate that elderly nursing home residents are extensively prescribed antiepileptic drugs (AEDs). Few studies have evaluated the prevalence of seizure-related diagnoses as a risk factor for AED administration in nursing homes. To assess the prevalence of AED use and of epileptic seizures in the elderly nursing home residents in our country, we considered age and gender data, functional status (measured by the Barthel's Index), drugs currently administered on a scheduled basis, clinical diagnoses from the patient's chart including possible history of epileptic seizures, of all subjects aged 60 years and over living in 21 federated nursing homes in the province of Pavia, Northern Italy. Data relating to 2.001 subjects (77.5 % females) were collected over a 4-month period (September-December 2000). Eighty-seven of the 2.001 residents (4.3%; 5.3% of all the males and 4.0% of all the females) were taking AEDs and 58 (3.5% of all the males and 2.7% of all the females), all of them under treatment with at least one AED, had epileptic seizures in their history. Both these subgroups had a mean modified Barthel's Index score significantly lower than that of the population as a whole. Phenobarbitone was the most frequently prescribed AED, and the penetration of newer AEDs was minimal. Subjects in early old age (60-74 years) were more likely than older subjects to take an AED. Logistic regression indicated a significant association between seizures reports, a younger age and a history of cerebrovascular events, alcohol abuse and meningiomas. The prevalence of AED use in this study was lower than that found by previous U.S. studies: nevertheless, our data confirm male gender and early old age as factors associated with AED taking in elderly nursing home residents. In our series AED users showed a lower level of autonomy. Taken together, our data suggest that an earlier institutionalization of seizure subjects could be facilitated by the clustering of various conditions, such as seizures, cerebrovascular events, other clinical disorders and a possibly inappropriate anticonvulsant treatment.

Optimizing antiepileptic drug therapy in the elderly

OBJECTIVE

To review and evaluate the medical literature concerning antiepileptic drug (AED) therapy in elderly patients.

DATA SOURCES

A MEDLINE search (1982-December 2004) was conducted. Bibliographies of the articles identified were also reviewed, and an Internet search engine was used to identify additional pertinent references.

STUDY SELECTION AND DATA EXTRACTION

Clinical studies and reviews were evaluated, and relevant information was included.

DATA SYNTHESIS

The elderly have the highest incidence of seizures among all age groups. Complex partial seizures are the most common, followed by primary generalized tonic-clonic seizures. An accurate diagnosis may prove difficult because of a low suspicion of epilepsy in the elderly and other diseases that may mimic seizures. Most AEDs are approved for treatment of elderly patients who have partial and tonic-clonic seizures. However, a number of age-related variables should be addressed when selecting an appropriate AED. Age-dependent differences in pharmacokinetics and pharmacodynamics of AEDs must be taken into account. Drug-drug interactions must be considered since elderly people often take multiple medications. The ultimate factor that often determines AED selection is tolerability.

CONCLUSIONS

Numerous factors must be considered in treating elderly patients for seizures, but maximizing the ability of patients to tolerate drug therapy is often the basis for AED selection. Special consideration should be made along several lines, including elderly patients' cognitive functioning and their tendency to respond to lower AED concentrations.

Adverse drug reactions in elderly patients

Many studies from around the world show a correlation between increasing age and adverse drug reaction (ADR) rate, at least for some medical conditions. More than 80% of ADRs causing admission or occurring in hospital are type A (dose-related) in nature, and thus predictable from the known pharmacology of the drug and therefore potentially avoidable. Frail elderly patients appear to be particularly at risk of ADRs and this group is also likely to be receiving several medicines. The toxicity of some drug combinations may sometimes be synergistic and be greater than the sum of the risks of toxicity of either agent used alone. In order to recognize and to prevent ADRs (including drug interactions), good communication is crucial, and prescribers should develop an effective therapeutic partnership with the patient and with fellow health professionals. Undergraduate and postgraduate education in evidence-based therapeutics is also vitally important. The use of computer-based decision support systems (CDSS) and electronic prescribing should be encouraged, and when problems do occur, health professionals need to be aware of their professional responsibility to report suspected adverse drug events (ADEs) and ADRs. "Rational" or "obligatory" polypharmacy is becoming a legitimate practice as increasing numbers of individuals live longer and the range of available therapeutic options for many medical conditions increases. The clear risk of ADRs in this situation should be considered in the context that dose-related failure of existing therapy to manage the condition adequately may be one of the most important reasons for admission of the elderly to hospital. Thus, age itself should not be used as a reason for withholding adequate doses of effective therapies.

Potentially Inappropriate Antiepileptic Drugs for Elderly Patients with Epilepsy

OBJECTIVES

To describe prescribing patterns for older veterans with epilepsy, determine whether disparity exists between these patterns and clinical recommendations, and describe those at greatest risk of receiving potentially inappropriate antiepileptic drugs (AEDs).

DESIGN

Retrospective administrative database analysis.

SETTING

All outpatient facilities within the Department of Veterans Affairs (VA).

PARTICIPANTS

All veterans aged 65 and older who had epilepsy diagnosed before the end of fiscal year 1999 (FY99) and who received AEDs from the VA in FY99 (N=21,435).

MEASUREMENTS

National VA pharmacy data were used to determine the AED regimen based on the AEDs patients received during the year. Administrative data were used to describe demographic variables and to gauge disease severity and epilepsy onset.

RESULTS

Approximately 17% of patients received phenobarbital and 54% phenytoin. Patients classified as having newly diagnosed disease were less likely to receive phenobarbital monotherapy and combination therapy and more likely to receive gabapentin or lamotrigine monotherapy (chi2=288.90, P<.001). Logistic regression analyses indicated that, for all patients, those with more severe disease were less likely to receive phenobarbital monotherapy than other monotherapy and phenobarbital combinations than other combinations. Those who received specialty consultation were less likely to receive phenytoin monotherapy than AED monotherapy, which is consistent with clinical recommendations.

CONCLUSION

Most older veterans received potentially inappropriate AED therapy. Hence, the standard of care for older patients with epilepsy should be reevaluated, although the vast use of phenytoin in this population suggests that change in practice patterns may be difficult.

Population pharmacokinetics of carbamazepine in Chinese epilepsy patients

AIM

To investigate the pharmacokinetic profile of carbamazepine (CBZ) in Chinese epilepsy patients.

MATERIALS AND METHODS

Serum samples through concentrations at steady state (n = 687) were collected prospectively from 585 patients during routine clinical care. Data were analyzed by the non-linear mixed-effect modeling (NONMEM) technique with a one-compartment model of first-order absorption and elimination.

RESULTS

The important determinants of clearance (CL) were total body weight (TBW); dose; patient age over 65 years (E); and comedication with phenytoin (PHT), phenobarbital (PB), or valproic acid (VPA) when VPA daily dose was greater than 18 mg/kg. The final pharmacokinetic model for relative CL and apparent distribution volume (V) were: Equation

CONCLUSION

A population pharmacokinetic model was proposed to estimate the individual CL for Chinese patients receiving CBZ in terms of patient's dose, TBW, and comedications to establish a priori dosage regimens.

Overtreatment in adults with epilepsy

Overtreatment of epilepsy patients is traditionally associated with the use of polytherapy, i.e. use of more than one antiepileptic drug (AED). Although monotherapy is now being used in 70% of patients with epilepsy, these patients are also at risk at being overtreated. Ten to 20% of patients withdraw from their first drug because of adverse effects. This is partly related to high starting dosages and fast titration rates. The conventional AEDs are still first choice monotherapy drugs, although they potentially have more adverse effects, especially in the elderly. Other problems are the random selection of second or third choice drugs and the uncertainty about when to switch to polytherapy. Several authors have suggested that patients with progressive forms of epilepsy, such as patients with mesiotemporal sclerosis, should be treated adequately as soon as possible and that epilepsy surgery should be considered for them in a much earlier stage. Overtreatment in polytherapy is still a large threat, due to several reasons: drug loads are much higher, and thus more adverse effects are likely to develop; drug combinations are selected randomly, as evidence about effective combinations has been scarce; the constant choice between continuing the existing treatment (which is suboptimal) and trying new drugs (which may disturb a patient's equilibrium); the long-term use of benzodiazepines.

Management of Epilepsy in Pediatrics and Geriatrics

For pediatric patients, the earlier in life epilepsy occurs, the lower are long-term mental abilities. Three rare but important conditions among infants and children--pyridoxine-deficiency seizures, Lennox-Gastaut syndrome, and West syndrome--usually require multidrug therapy to control seizures. Epilepsy occurs more frequently among the elderly and therapy is complicated by treatment of other chronic medical conditions. Numerous effective antiepileptic medications for both pediatric and geriatric patients have been newly marketed in the past decade, with other promising agents in the investigational drug pipeline.