Developmental Outcome of Levetiracetam, Its Major Metabolite in Humans, 2‐Pyrrolidinone N‐Butyric Acid, and Its Enantiomer (R)‐α‐ethyl‐oxo‐pyrrolidine Acetamide in a Mouse Model of Teratogenicity

Abstract

Summary:Purpose: The purpose of this study was to test the teratogenic potential of the antiepileptic drug (AED) levetiracetam (LEV), its major metabolite in humans, 2-pyrrolidone-Nbutyric acid (PBA), and enantiomer, (R)-α-ethyl-oxo-pyrrolidine acetamide (REV), in a well-established mouse model.Methods: All compounds were administered by intraperitoneal injections once daily to SWV/Fnn mice on gestational days 8 1 2 to 12 1 2 . LEV was administered at doses of 600, 1,200, and 2,000 mg/kg/day, piracetam (PIR) and PBA, at 600 and 1,200 mg/kg/day, and REV, at 600 mg/kg/day. On gestational day 18 1 2 , fetuses were examined for gross external malformations and prepared for skeletal analysis by using Alizarin Red S staining.Results: No significant gross external malformations were observed in any of the study groups. Fetal weights were significantly reduced in most study groups. Resorption rates were significantly increased only in the 2,000-mg/kg/day LEV group. The overall incidence of skeletal abnormalities and specifically of hypoplastic phalanges was significantly increased in both PBA treatments and in the intermediate 1,200-mg/kg/day LEV group. In contrast to that in humans, 24-h urinary excretion analysis in mice showed that 65-100% of the LEV doses were excreted unchanged, whereas only 4% was excreted as the metabolite PBA. Conclusions:Results of this study demonstrate that both LEV and its major metabolite in humans, PBA, do not induce major structural malformations in developing SWV/Fnn embryos and suggest that they provide a margin of reproductive safety for the pregnant epileptic population when compared with other AEDs tested in this mouse model.

Antiepileptic Drugs and Pregnancy Outcomes

“…Results of this study demonstrate that both LEV, and its major human metabolite, PBA, do not induce major structural malformations in developing SWV embryos [Isoherranen et al, 2003]. Similar results were observed in experiments on rats and rabbits [Thomson/ Micromedex, 2007].…”

Stir bar-sorptive extraction, solid phase extraction and liquid-liquid extraction for levetiracetam determination in human plasma: comparing recovery rates

“…Considering the high hydrophilic characteristic of LEV, our present elution performed with dichloromethane can possibly explain the low recovery rates found (Table I) and to what is reported elsewhere (Isoherranen et al, 2000;Pucci et al, 2004;Vermeij,Edelbroek, 1994;Zufia et al, 2010). Among the organic solvents commonly used in SPE, dichloromethane has a polarity index of 3.4, while it is 6.6 for methanol.…”

“…Several chromatographic methods have been published for quantification of LEV concentrations in biological fluids such as saliva and plasma (or serum) for TDM and in urine for pharmacokinetic aims. They include different subtypes of liquid chromatography with various detection systems (Contin et al, 2008;Grim et al, 2003;Guo et al, 2007;Jain et al, 2006;Juenke et al, 2006;Kuhn, Knabbe, 2013;Lancelin et al, 2007;Martens-Lobenhoffer, BodeBoger, 2005;Matar, 2008;Pucci et al, 2004;Rao et al, 2004;Ratnaraj, Doheny, Patsalos, 1996;Shibata et al, 2012), gas chromatography (Isoherranen et al, 2000;Mecarelli et al, 2007) and microemulsion electrokinetic chromatography (Ivanova et al, 2003). An analytical nonchromatographic method, capillary electrophoresis, is also described (Shihabi, Oles, Hinsdale, 2003).…”

“…Solidphase extractions (SPE) of LEV performed with different polymeric sorbents such as C 18 and hydrophilic-lipophilic balanced copolymer are described in the literature (Isoherranen et al, 2000;Ivanova et al, 2003;Mecarelli et al, 2007;Pucci et al, 2004;Vermeij, Edelbroek, 1994). Protein precipitation is considered a simple, inexpensive and suitable pretreatment procedure especially for drugs minimally bound to plasma proteins.…”

“…Although time-consuming and highly dependent on organic solvents, LLE is a feasible and inexpensive method used both for TDM and pharmacokinetics purposes (Chollet, 2002;Isoherranen et al, 2003;Patsalos et al, 2006).…”