title: Pharmacodynamic and pharmacokinetic analysis of CNS-active constitutional isomers of valnoctamide and sec-butylpropylacetamide--Amide derivatives of valproic acid.
abstract: Valnoctamide (VCD) and sec-butylpropylacetamide (SPD) are CNS-active closely related amide derivatives of valproic acid with unique anticonvulsant activity. This study evaluated how small chemical changes affect the pharmacodynamics (PD; anticonvulsant activity and teratogenicity) and pharmacokinetics (PK) of three constitutional isomers of SPD [sec-butylisopropylacetamide (SID) and tert-butylisopropylacetamide (TID)] and of VCD [tert-butylethylacetamide (TED)]. The anticonvulsant activity of SID, TID, and TED was comparatively evaluated in several rodent anticonvulsant models. The PK-PD relationship of SID, TID, and TED was evaluated in rats, and their teratogenicity was evaluated in a mouse strain highly susceptible to teratogen-induced neural tube defects (NTDs). sec-Butylisopropylacetamide and TID have a similar PK profile to SPD which may contribute to their similar anticonvulsant activity. tert-Butylethylacetamide had a better PK profile than VCD (and SPD); however, this did not lead to a superior anticonvulsant activity. sec-Butylisopropylacetamide and TED did not cause NTDs at doses 4-7 times higher than their anticonvulsant ED50 values. In rats, SID, TID (ip), and TED exhibited a broad spectrum of anticonvulsant activity. However, combined anticonvulsant analysis in mice and rats shows SID as the most potent compound with similar activity to that of SPD, demonstrating that substitution of the isobutyl moiety in the SPD or VCD molecule by tert-butyl as well as a propyl-to-isopropyl replacement in the SPD molecule did not majorly affect the anticonvulsant activity.
authors: School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.
authors: Hafiz
authors: H
authors: Mawasi
authors: School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.
authors: Tawfeeq
authors: T
authors: Shekh-Ahmad
authors: Department of Nutritional Sciences, Dell Pediatric Research Institute, The University of Texas at Austin, Austin, TX, USA.
authors: Richard H
authors: RH
authors: Finnell
authors: Department of Nutritional Sciences, Dell Pediatric Research Institute, The University of Texas at Austin, Austin, TX, USA.
authors: Bogdan J
authors: BJ
authors: Wlodarczyk
authors: School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Israel. Electronic address: bialer@md.huji.ac.il.
authors: Meir
authors: M
authors: Bialer
mesh_terms: D000577:Amides / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D000927:Anticonvulsants / Q000493:pharmacokinetics / Q000494:pharmacology / Q000633:toxicity; D005260:Female; D007536:Isomerism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000188:drug therapy*; D014635:Valproic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology / Q000633:toxicity
chemical_list: D000577:Amides; D000927:Anticonvulsants; C570212:sec-butyl-propylacetamide; C045179:valnoctamide; D014635:Valproic Acid
keywords: CNS drugs; Constitutional isomers; New antiepileptic drugs (AEDs); Structure–pharmacokinetic (PK)–pharmacodynamic (PD) relationship; Valnoctamide (VCD); sec-Butylpropylacetamide (SPD)