RESUMO
Propofol [25, 50 and 100 mg/kg], thiopentone [12.5, 25 and 50 mg/kg] and midazolam [1, 2, 5 and 10 mg/kg] were injected intraperitoneally [i.p.] in adult albino mice. They produced a qualitatively similar behavioral effects. They caused a dose-dependent CNS inhibition ranged from mild sedation up to general anesthesia. These drugs had comparable onset and peak of action. Propofol had a statistically significant shortest duration of action. Based on weight/weight, the sedative potency of midazolam: thiopentone: propofol was 10: 2: 1, respectively. Convulsions were induced in mice by i.p. injection of PTZ in a dose range of 50-300 mg/kg. I.p. administration of propofol, thiopentone and midazolam in the aforementioned doses, prior to PTZ, exhibited an anticonvulsant effect and protected the animals from convulsions and mortalities. This protective effect was proportional to the dose. In the small and moderate doses, propofol and thiopentone had comparable protective effects. In the high dose, thiopentone was significantly more protective than propofol. In all doses, midazolam manifested a statistically significant higher protective activity over that of propofol and thiopentone