Amiloride enhances the anticonvulsant action of various antiepileptic drugs in the mouse maximal electroshock seizure model

J Neural Transm (Vienna). 2009 Jan;116(1):57-66. doi: 10.1007/s00702-008-0152-2. Epub 2008 Nov 22.

Abstract

Accumulating evidence indicates that amiloride (a potassium-sparing diuretic) exerts the anticonvulsant action in various in vivo and in vitro experiments. Therefore, the objective of this study was to assess the influence of amiloride on the protective action of numerous conventional and second-generation antiepileptic drugs [AEDs: carbamazepine (CBZ), lamotrigine (LTG), oxcarbazepine (OXC), phenobarbital (PB), topiramate (TPM), and valproate (VPA)] against maximal electroshock (MES)-induced seizures in mice. Results indicate that amiloride [up to 100 mg/kg, intraperitoneally (i.p.), at 30, 60, and 120 min before the test] neither altered the threshold for electroconvulsions, nor protected the animals against MES-induced seizures in mice. Moreover, amiloride (75 and 100 mg/kg, i.p., 120 min prior to the test) significantly enhanced the anticonvulsant effects of all studied AEDs, except for LTG, by reducing their ED(50) values in the MES test. In contrast, amiloride at 50 mg/kg (i.p.) had no significant effect on the antielectroshock action of the tested AEDs in mice. Estimation of total brain AED concentrations revealed that amiloride (75 mg/kg) significantly increased total brain concentrations of CBZ, OXC, and PB, but not those of LTG, TPM, and VPA in mice. In conclusion, one can ascertain that the potentiation of the antiseizure action of TPM and VPA by amiloride in the MES test and lack of any pharmacokinetic interactions between drugs, make the combinations of amiloride with TPM and VPA of pivotal importance for epileptic patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amiloride / therapeutic use*
  • Analysis of Variance
  • Animals
  • Anticonvulsants / pharmacokinetics
  • Anticonvulsants / therapeutic use
  • Avoidance Learning / drug effects
  • Brain / drug effects
  • Brain / metabolism
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drug Synergism
  • Electroshock / adverse effects*
  • Male
  • Mice
  • Motor Activity / drug effects
  • Muscle Strength / drug effects
  • Psychomotor Performance / drug effects
  • Seizures / drug therapy*
  • Seizures / etiology*
  • Seizures / pathology
  • Sodium Channel Blockers / therapeutic use*
  • Time Factors

Substances

  • Anticonvulsants
  • Sodium Channel Blockers
  • Amiloride