Elsevier

Brain Research

Volume 1556, 27 March 2014, Pages 10-18
Brain Research

Research Report
Levetiracetam increases neonatal hypoxic-ischemic brain injury under normothermic, but not hypothermic conditions

https://doi.org/10.1016/j.brainres.2014.01.034Get rights and content

Highlights

  • In the undamaged developing rodent brain levetiracetam does not exert a neurotoxic effect.

  • Levetiracetam aggravates neonatal hypoxic-ischemic brain injury under normothermic but not under hypothermic conditions.

  • In newborn infants with pre-existing brain injury levetiracetam should be used with caution.

Abstract

Background

Hypoxic-ischemic encephalopathy (HIE) resulting from perinatal asphyxia often leads to severe neurologic impairment or even death. There is a need to advance therapy for infants with HIE, for example to combine hypothermia with pharmacological treatment strategies. Levetiracetam (LEV) is approved for clinical administration to infants older than 4 weeks of age and is also used off-label in neonates. Furthermore, LEV was shown to be neuroprotective in adult animal models of brain injury.

Aim of the study

The aim of this study was to evaluate the neuroprotective potential of LEV in vitro using primary hippocampal neurons, and in vivo using an established model of neonatal hypoxic-ischemic brain injury.

Results

LEV treatment per se did not induce neurotoxicity in the developing rodent brain. Following oxygen glucose deprivation, we observed some, although not a significant, increase in cell death after LEV treatment. In vivo, LEV was administered under normothermic and hypothermic conditions following hypoxic-ischemic brain damage. LEV administration significantly increased brain injury under normothermic conditions. Compared to the normothermia-treated group, in the hypothermia group LEV administration did not increase hypoxic-ischemic brain injury.

Discussion

This study demonstrates that LEV treatment increases neonatal hypoxic-ischemic brain injury. Administration of LEV in the acute phase of the injury might interfere with the balanced activation and inactivation of excitatory and inhibitory receptors in the developing brain. The neurotoxic effect of LEV in the injured newborn brain might further suggest an agonistic effect of LEV on the GABAergic system. Hypothermia treatment attenuates glutamate release following hypoxic-ischemic brain injury and might therefore limit the potentially deleterious effects of LEV. As a consequence, our findings do not necessarily rule out a potentially beneficial effect, but argue for cautious use of LEV in newborn infants with pre-existing brain injury.

Introduction

With an incidence of 0.5 to–1/1000 live births in resource-rich countries, perinatal asphyxia is still one of the main reasons for perinatal death and severe neurologic impairment (Levene et al., 1985). Several treatment strategies have been tested and valuable information was gathered concerning the underlying pathomechanisms of neonatal brain injury (Lobo et al., 2013, Souvenir et al., 2011). In recent years, therapeutic hypothermia has been shown to be of substantial benefit to asphyxiated newborn infants suffering from hypoxic-ischemic encephalopathy (HIE) and is now an established therapy (Shankaran, 2012). However, only a minority of infants survive without handicap (Edwards et al., 2010), which distinctly shows that there is still a need to advance therapy, for example to combine hypothermia with pharmacological treatment strategies. Neonatal seizures are a common feature in HIE. Hypothermia was shown to reduce seizure activity in infants suffering from HIE (Srinivasakumar et al., 2013). In spite of little neuronal loss, seizures may alter neuronal circuitry in the developing brain, resulting in impaired learning and memory (Holmes, 2009). They may also substantially increase the central nervous system׳s metabolic demand and could therefore exacerbate pre-existing brain injury. Despite almost 10 years of evidence that medications commonly used in newborns are ineffective and potentially neurotoxic to the developing brain (Bittigau et al., 2002, Stefovska et al., 2008), the clinical management of neonatal seizures has remained unchanged for more than a generation. However, anticonvulsants that also possess neuroprotective effects could further improve the outcome of asphyxiated newborn infants.

Levetiracetam ((S)-α-ethyl-2-oxo-1-pyrrolidine acetamide) (LEV), an anti-epileptic drug of the second generation belonging to the chemical class of pyrrolidines, has a wide spectrum of actions. LEV shows a favorable pharmacokinetic profile in the pediatric population and has already been approved for clinical use in infants older than 4 weeks of age (Beaulieu, 2013). Moreover, it is frequently recommended for the treatment of neonatal seizures (Silverstein and Ferriero, 2008) and has been shown to have neuroprotective properties (Hanon and Klitgaard, 2001, Kilicdag et al., 2013).

The aim of this study was to evaluate the neuroprotective potential of LEV in an in vitro and an in vivo model of hypoxic-ischemic brain injury under normothermic and hypothermic conditions.

Section snippets

Application of LEV does not prevent neuronal cell death induced by OGD

Kruskal–Wallis analysis showed a significant overall difference in neuronal cell death in primary hippocampal neurons (H=7.731, p=0.007). Post-hoc analysis with the Student–Newman–Keuls method revealed that primary hippocampal neurons exposed to OGD showed a significantly increased cell death ratio as compared to control cells (OGD control: 37.35 [24.91; 42.60] versus control: 15.36 [10.31; 17.53]; n=4, p<0.05). Administration of LEV at a dosage of 100 µM and 300 µM, both, did not reduce neuronal

Discussion

Neonatal seizures are frequent, especially in the case of HIE (van Rooij et al., 2013). Anticonvulsive drugs routinely used in adult and pediatric patients are increasingly being administered for the treatment of neonatal seizures as well. However, data on the safety and potentially adverse effects regarding the use of these substances in neonates are sparse (van Rooij et al., 2013). We need to consider that drugs administered to treat neonatal seizures, or that have been described to exert

Conclusion

In conclusion this study demonstrates that LEV treatment increases newborn brain damage following hypoxic-ischemic injury. This neurotoxic effect in the immature brain might be explained by an agonistic action of LEV on components of the GABAergic system, but to elucidate this in detail, more experimental work is required. Our findings do not necessarily rule out a potentially beneficial effect, but, at present LEV should be used cautiously in newborn infants with pre-existing brain injury.

Materials

Substances used for in vitro experiments were purchased from Invitrogen (Life Technologies, Germany), except cytosine ß-d-arabinofuranoside (AraC) and general chemicals (Sigma-Aldrich, Austria). Substances for in vitro cell staining were purchased from Sigma-Aldrich, Austria (propidium iodide), or Calbiochem Millipore, Austria (calcein-AM). Ibotenate was purchased from Tocris Bioscience (R&D Systems, Germany). LEV (trade name Keppra®) was obtained from UCB Pharma SA; Forane® (Isoflurane) from

Financial statement

This work was supported by the Tyrolean Research Fund (Grant: UNIV-0404-1123) and the Austrian Science Fund (Grants: FWF P24079 and F4406).

Contributors׳ statement

There is no conflict of interest. No form of payment was given to anyone to produce the manuscript. All authors approved the final version of this manuscript to be published.

Acknowledgments

We thank Ao. Univ.-Prof. Dr. med. vet. Hermann Dietrich (Central Laboratory Animal Facility, Innsbruck Medical University) for kindly sharing his expertise on animal experiments and Dr. rer. nat. Martin Hermann (Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University), who shared his valuable expertise in fluorescence imaging.

References (38)

Cited by (23)

  • Acute symptomatic seizures in term neonates: Etiologies and treatments

    2018, Seminars in Fetal and Neonatal Medicine
    Citation Excerpt :

    Additionally, LEV was usually administered as second- or third-line therapy, when acute seizures were likely subsiding [38,39]. There are mixed results from rodent studies regarding any neuroprotective effect, so it is unclear whether there is any additive benefit to using LEV for acute symptomatic seizures in newborns [40,41]. Currently, whereas LEV appears to be safe and has predictable pharmacokinetics, its use in newborns is limited by the uncertainty regarding its efficacy and optimal dosing – data which may become available with completion of ongoing or future clinical trials.

  • The use of phenobarbital and other anti-seizure drugs in newborns

    2017, Seminars in Fetal and Neonatal Medicine
    Citation Excerpt :

    Topiramate has multiple mechanisms of action, including modulation of glutamate activity at the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and kainate receptors in addition to the modulation of GABA activity at GABA receptors [69,70]. Its neuroprotective role has been demonstrated in numerous animal models for HI brain injury, stroke, refractory seizures, and periventricular leukomalacia, making it a potentially promising ASD for newborns with symptomatic seizures caused by acute brain injury [44,45,71,72]. The pharmacokinetics of topiramate have been described in infants and in neonatal animal models [73] and one human neonatal study [74].

  • Administration of secretoneurin is protective in hypoxic–ischemic neonatal brain injury predominantly in the hypoxic-only hemisphere

    2017, Neuroscience
    Citation Excerpt :

    Absorbance was measured at 450 nm by means of a multichannel 96-well visible microplate reader (Hidex Sense™, HVD Lifesciences, Vienna, Austria). Primary hippocampal cultures were prepared from 16.5-day-old embryonic mice as described previously (Obermair et al., 2004; Griesmaier et al., 2014). Oxygen–glucose deprivation (OGD) as a cell culture model of hypoxic–ischemic injury was performed on in vitro day 10 (Griesmaier et al., 2014).

  • Unfavorable effect of levetiracetam on cultured hippocampal neurons after hyperthermic injury

    2017, Pharmacological Reports
    Citation Excerpt :

    The drug has demonstrated good tolerability and efficacy against seizures as adjunctive therapy or monotherapy in children, including children aged 1 month to <4 years [26,27]. Data from the literature showed both favorable [28,29] and unfavorable [30,31] effects of LEV on nerve cell survival in varied models of neuronal injury. In our previous study, we showed that LEV exerted a promising neuroprotective effect on cultured hippocampal neurons after hypoxic damage.

View all citing articles on Scopus
View full text