Drug interaction between halothane anaesthesia and the alpha[2]-adrenergic agonist, Ca[+2] entry blockers and K[+]-channel openers with possible effects on brain catecholamines

ABSTRACT

The interaction between halothane anaesthesia and 3 important groups of drug viz alpha[2] adrenergic agonist [clonidine], Ca[+2] entry blocker [diltiazem] and K[+] channel opener [nicorandil] was studied in Albino rats. Rats were pretreated with clonodine [Catapress] 0.1 mg/kg b.wt. in clonidine group, with Diltiazem[Diltiem] 0.25 mg/kg b.wt. in diltiazem group and with nicorandil [Sigmart] 0.2 mg/kg b.wt. in nicorandil group. Drugs were given one hour before exposure to halothane anaesthesia. It was found that, clonidine resulted in reduction of the anaesthetic requirements with associated significant decrease of brain catecholamines from the mean control value of 620,584 +/- 28,460 pg/ml to the mean value 351.548 +/- 31.700 pg/ml [F = 163.636 at P > 0.05]. The other two groups showed no significant changes