Anticonvulsant and psychomotor activity of nitrendipine alone and in combination with phenytoin and valproate in rats

The effect of nitrendipine (NTP) alone and in combination with phenytoin (P HT) and valproate (VPA) against;maximal electroshock seizures (MES) was stu died in rats. In addition, the psychomotor effects of NTP alone and in comb ination with PHT and VPA were evaluated using the fol lowing tests: a) rota rod performance; b) spontaneous motor activity; c) despair behavior; d) rig hting reflex; e) hole board rest; and f) passive avoidance rest. ED50 value s of PHT, VPA and NTP were 13, 255 and 3.6 mg/kg, respectively. When NTP wa s combined with PHT or VPA, the ED,, values decreased to 0.9 and 226 mg/kg, respectively. In the psychomotor function tests, for the same degree of pr otection (50%) afforded against MES, PHT or VPA produced a greater impairme nt in all the parameters compared to NTP alone or a combination of NTP with PHT or VPA. Furthermore, NTP reversed the depression and long-term memory loss induced by PHT and VPA. Thus, NTP was effective against MES in mrs, po tentiating the anti electroshock activity of PHT and VPA and producing less impairment of psychomotor activity. Thus, the agent can be considered a po tential antiepileptic warnantng further studies. (C) 1999 Prous Science. Al l rights reserved.