Metabolic consequences of antiepileptic drugs

Purpose of Review: Chemical properties of the widely used older generation antiepileptic drugs (AEDs) suggest that they might be responsible for a number of medical comorbidities. Recent Findings: AEDs which induce the cytochrome P450 system adversely affect bone, lipid, and gonadal steroid metabolism. Specifically, phenytoin causes loss of bone mass in women, and both phenytoin and carbamazepine produce increases in serum lipids and C-reactive protein, as well as decreases in bioactive testosterone in men. Patients treated with inducing AEDs are at increased risk of fracture. Some contradictory data raise the question of whether bone mass is truly related to enzyme induction, and analogously, of whether reductions in testosterone truly account for male sexual dysfunction. Data showing elevations of surrogate cardiovascular and cerebrovascular risk endpoints with epilepsy patients, mostly inducing AED treated, are consistent and concerning, however. Another older AED, valproate, is associated with the occurrence of polycystic ovary syndrome when used in young adulthood or adolescence. Summary: Older generation AEDs are associated with a panoply of metabolic abnormalities. Although more research is needed to see whether individual drugs are directly tied to specific clinical outcomes (e.g. risk of infarction), extant data are sufficiently concerning to suggest that these drugs may produce significant adverse health consequences. Newer generation AEDs may be preferable

Plumbing and wiring: Atherosclerosis in epilepsy.

Over the long term, epilepsy is clearly associated with cognitive impairment. This has been demonstrated functionally, using neuropsychological testing, and reinforced by structural studies showing progressive atrophy in patients with chronic epilepsy 1-3. The prevailing explanation for this, of course, has been the direct and cumulative effects of seizures on the brain. The basic science literature is chock full of studies showing impairment of neuronal function after seizures, both acutely and chronically. And for those of us who see patients, the progressive memory complaints and clear-cut decline in function seen in those with drug-resistant epilepsy — particularly temporal lobe epilepsy — appear to sufficiently attest to the fact that the seizures are the culprit

Use of antiepileptic drugs and lipid-lowering agents in the United States.

INTRODUCTION: The extent to which enzyme-inducing antiepileptic drugs (EIAEDs) are used as first-line treatment in the United States remains unknown. Studies suggest that EIAEDs produce elevation of serum lipids, which could require additional treatment. We assessed the current use of EIAED in monotherapy for epilepsy in the U.S., as well as the correlation between the use of EIAEDs and subsequent new prescriptions for HMG-CoA reductase inhibitors ( statins ) for hyperlipidemia. METHODS: We queried the MarketScan® databases between July 2009 and January 2013, covering 66million patients with commercial or supplemental Medicare insurance. We identified individuals who had a diagnosis of seizures, continuous enrollment in the database from 6months prior to 24months after the epilepsy diagnosis, no utilization of an AED or a statin prior to that diagnosis, and at least 1 new AED prescription. We tabulated the fraction of subjects who were prescribed EIAEDs (phenytoin, carbamazepine, or barbiturates) and those prescribed all other AEDs. Rates of new statin prescription between 1 and 24months after AED prescription were assessed among the two groups, restricted to those with no prior history of vascular disease who had lipid serology obtained subsequent to the new AED prescription. RESULTS: Of the 11,893 patients with newly treated epilepsy, 2425 (20.4%) were started on an EIAED, and 9468 (79.6%) were started on a noninducing AED. There was a consistent and significant trend for EIAEDs to be increasingly prescribed with increasing age (p CONCLUSIONS: Enzyme-inducing antiepileptic drug prescription for epilepsy appears to increase with increasing age in the U.S. despite the absence of a cogent rationale for this practice, suggesting a failure to appreciate the complications of EIAED therapy among U.S. physicians. Statins were more often prescribed to those newly treated with EIAEDs compared with those given noninducing AEDs. These preliminary data provide further evidence suggesting that EIAEDs elevate lipids in a clinically meaningful manner

Evaluation of perampanel as monotherapy for focal seizures: Experience from open-label extension studies

Perampanel, a selective, non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, is approved for adjunctive treatment of focal seizures, with or without secondarily generalized seizures, and for primary generalized tonic–clonic seizures in patients with epilepsy aged ≥ 12 years. Perampanel was recently approved for monotherapy use for focal seizures in the U.S.A. Anti-seizure drug monotherapy may be preferable to polytherapy, which is generally associated with increased toxicity, non-compliance, and cost. Here, we report cases where patients had converted to perampanel monotherapy during open-label extension (OLEx) portions of 9 Phase II and III studies. Of 2245 patients who enrolled in the OLEx studies, we identified 7 patients with drug-resistant focal seizures who discontinued all non-perampanel anti-seizure drugs and were maintained on perampanel monotherapy for ≥ 91 days until the end of data cut-off. Patients received perampanel monotherapy for up to 1099 days (157 weeks), most at a modal dose of 12 mg. Seizure data were available for 6 patients, of whom 5 had a ≥ 90% reduction in overall seizure frequency between baseline and their last 13-week period of monotherapy (3 were seizure-free). Perampanel monotherapy was generally well tolerated and the safety profile during perampanel monotherapy was consistent with clinical and post-marketing experience in the adjunctive setting. This analysis included a small proportion of patients with highly drug-resistant focal seizures who converted to monotherapy during OLEx studies. While these limited data are encouraging in suggesting that perampanel might be useful as a monotherapy, further studies are required to explore outcomes in a less drug-resistant population, where a larger proportion of patients might benefit from monotherapy. © 2017 The Author

Seizure outcome after switching antiepileptic drugs: A matched, prospective study.

OBJECTIVE: Outcomes after changing antiepileptic drugs (AEDs) have largely been studied in single cohort series. We recently reported the first study to examine this question in a controlled manner. Here we expand on these results by using a matched, prospective methodology applied to both uncontrolled and well-controlled patients taking any AED. METHODS: We reviewed all outpatient notes over a 9-month period and identified patients with focal epilepsy who were on monotherapy. We classified those who switched AEDs as case patients, with those remaining on the same drug serving as controls. We matched cases with controls for seizure status (seizure-free in the preceding 6 months or not), current AED, and number of failed AEDs. We subsequently assessed outcome 6 months later. RESULTS: Seizure-free patients who switched drug (n = 12) had a 16.7% rate of seizure recurrence at 6 months, compared to 2.8% among controls remaining on the same drug (n = 36, p = 0.11). There was a 37% remission rate among uncontrolled patients who switched drug compared to 55.6% among controls (n = 27 per group, p = 0.18). Uncontrolled patients who had previously tried more than one AED were somewhat less likely to enter remission (p = 0.057). Neither AED mechanism of action nor change in dosage impacted outcome. SIGNIFICANCE: Herein we provide further estimation of the modest risk (~14%) associated with switching AEDs in patients in remission compared to being maintained on the same regimen. Uncontrolled patients were no more likely to enter remission after a drug switch than they were after remaining on the same drug, suggesting that spontaneous changes in disease state, and not drug response, underlie remission in this population

Long-term effect of antiepileptic drug switch on serum lipids and C-reactive protein.

BACKGROUND: Prior studies have shown that switching patients from inducing antiepileptic drugs (AEDs) to lamotrigine, levetiracetam, or topiramate reduces serum lipids and C-reactive protein (CRP). These studies were all of short duration, and some drugs, such as zonisamide, have not been investigated. METHODS: We recruited 41 patients taking phenytoin or carbamazepine who were being switched to zonisamide, lamotrigine, or levetiracetam. We measured serum lipids and CRP before the switch, \u3e6weeks after, and \u3e6months after. An untreated control group (n=14) underwent similar measurement. We combined these data with those of our previous investigation (n=34 patients and 16 controls) of a very similar design. RESULTS: There were no differences in outcome measures between the two inducing AEDs nor among the three noninducing AEDs. Total cholesterol (TC), atherogenic lipids, and CRP were higher under inducer treatment than in controls. All measures were elevated under inducer treatment relative to noninducer treatment, including TC (24mg/dL higher, 95% CI: 17.5-29.9, p CONCLUSIONS: We demonstrate that switching from inducing to noninducing AEDs produces an enduring reduction in serum lipids and CRP. These results provide further evidence that inducing AEDs may be associated with elevated vascular disease risk. These are the first vascular risk marker data in patients taking zonisamide, which shows a profile similar to that of other noninducing AEDs

Markers of bone and lipid metabolism with eslicarbazepine acetate monotherapy.

OBJECTIVE: To evaluate the impact of eslicarbazepine acetate (ESL) monotherapy on markers of bone and lipid metabolism. METHODS: We conducted a post-hoc analysis of data pooled from two Phase III, dose-blind, conversion-to-ESL (1600 mg and 1200 mg) monotherapy studies in patients with focal seizures. Laboratory measurements included lipids (total cholesterol [TC]; high-density lipoprotein cholesterol [HDL-C]; low-density lipoprotein cholesterol; and triglycerides) and markers of bone metabolism (alkaline phosphatase; 25-hydroxyvitamin D; osteocalcin; and parathyroid hormone [PTH]); measurements were taken at baseline, Week 18, and Month 12, and analyzed according to enzyme-inducing antiepileptic drugs (EIAEDs) use at baseline (+EIAED and -EIAED subgroups). RESULTS: Data from 337 treatment-compliant patients were used for the Week 18 analyses (+EIAED subgroup, n = 119; -EIAED subgroup, n = 218); data from 161 treatment-compliant patients were used for the Month 12 analyses (+EIAED subgroup, n = 53; -EIAED subgroup, n = 108). At baseline, alkaline phosphatase and PTH concentrations were higher in the + EIAED versus -EIAED subgroup. Changes from baseline in markers of bone turnover were generally insignificant, except for some elevation in alkaline phosphatase in the -EIAED subgroup (18 weeks and 12 months) and osteocalcin in both subgroups (18 weeks only). Regarding lipids, TC and HDL-C concentrations were higher in the + EIAED versus -EIAED subgroup at baseline. Concentrations of markers of lipid metabolism fell in the + EIAED group and rose in the -EIAED group, reaching very similar values that were intermediate between the -EIAED and + EIAED baseline values. CONCLUSIONS: Based on this retrospective analysis, ESL seems to have had only a modest and primarily clinically insignificant impact on plasma lipids. More prospective data are needed to definitively ascertain the effects of ESL on bone metabolism

Carbamazepine treatment of generalized tonic–clonic seizures in idiopathic generalized epilepsy

AbstractPurposeEvaluate the efficacy of carbamazepine in the treatment of idiopathic generalized epilepsy (IGE).MethodThe response of five patients with IGE, who experienced primarily generalized tonic–clonic seizures which were refractory to multiple antiepileptic drugs, is reported.ResultsCarbamazepine controlled multiple seizure types and did not induce or increase the frequency of myoclonic or absence seizures in these patients. Many family members also responded favorably to carbamazepine.ConclusionCarbamazepine can be used with caution as an alternative treatment option for refractory IGE, especially in cases in which the main seizure type is generalized tonic–clonic

Two successive calcium-dependent transitions mediate membrane binding and oligomerization of daptomycin and the related antibiotic A54145

The final publication is available at Elsevier via http://doi.org/10.1016/j.bbamem.2016.05.020 © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Daptomycin and A54145 are homologous lipopeptide antibiotics that permeabilize the cell membranes of Gram-positive bacteria. Membrane permeabilization depends on the presence of both phosphatidylglycerol (PG) and calcium, and it involves the formation of oligomeric transmembrane pores that consist of approximately 6-8 subunits. We here show that each lipopeptide molecule binds two calcium ions in separable, successive steps. The first calcium ion causes the lipopeptide molecule to bind to the target membrane, and likely to form a loosely associated oligomer. Higher calcium concentrations induce binding of a second ion, which produces the more tightly associated and more deeply membrane-inserted final, functional form of the oligomer. Both calcium dependent steps are accompanied by fluorescence signals that indicate transition of specific amino acid residues into less polar environments, suggestive of insertion into the target membrane. Our findings agree with the earlier observation that two of the four acidic amino acid residues in the daptomycin molecule are essential for antibacterial activity. (C) 2016 Elsevier B.V. All rights reserved.This study was supported by operating grants by NSERC to Scott Taylor (155283-2012) and Michael Palmer (250265-2013)

Effects of adjunctive eslicarbazepine acetate on serum lipids in patients with partial-onset seizures: Impact of concomitant statins and enzyme-inducing antiepileptic drugs.

PURPOSE: To evaluate the effects of eslicarbazepine acetate (ESL) on lipid metabolism and to determine whether reduced statin exposure during ESL therapy has clinical consequences. SUBJECTS AND METHODS: We conducted a post-hoc analysis of pooled data for serum lipids (laboratory values) from three phase III, multicenter, randomized, double-blind, placebo-controlled trials of adjunctive ESL therapy (400, 800, or 1200 mg once daily) in patients with treatment-refractory partial-onset seizures. Changes from baseline in serum lipid levels were analyzed according to use of statins and/or enzyme-inducing antiepileptic drugs (EIAEDs) during the baseline period. KEY FINDINGS: In total, 426 and 1021 placebo- and ESL-treated patients, respectively, were included in the analysis. With regard to the changes from baseline in serum concentrations, there were statistically significant differences between the placebo and ESL 1200 mg QD groups, for both total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C), but the effect sizes were small (+4.1 mg/dL and +1.8 mg/dL, respectively). A small but significant difference in low-density lipoprotein cholesterol (LDL-C; -5.0 mg/dL) was observed between the ESL 400 mg QD group and the placebo group. In patients not taking a concomitant EIAED, there were no changes with ESL 400 mg QD, but modest and statistically significant increases in cholesterol fractions (TC, LDL-C and HDL-C) with ESL 800 mg QD (/dL) and ESL 1200 mg QD (/dL). ESL had no consistent effect on lipids in patients taking a concomitant EIAED. In patients taking statins during baseline, there were no clinically relevant changes in serum lipids during use of ESL, although the subgroups were small. SIGNIFICANCE: These results suggest that ESL does not appear to have clinically significant effects on serum lipids, nor does the pharmacokinetic interaction between ESL and statins have an impact on serum lipid concentrations