Flumazenil does not antagonize halothane, thiamylal or propofol anaesthesia in rats.
We have studied the effects of flumazenil on sleep time and EEG in rats anaesthetized with 1.5% halothane, propofol 20 mg kg-1, thiamylal 30 mg kg-1, or combinations of diazepam 5 mg kg-1 and anaesthetic agents. We also studied the effects of flumazenil 0.3, 3 and 30 mg kg-1 on behaviour and EEG. Flumazenil 0.3 and 3 mg kg-1 alone had no effect on behaviour or EEG, but flumazenil 30 mg kg-1 had depressive effects similar to those of diazepam on behaviour and EEG. Flumazenil 0.3, 3 and 30 mg kg-1 i.v., antagonized the effects of diazepam 10 mg kg-1 i.v. on behaviour and EEG. Flumazenil had no antagonistic effect on sleep time induced by anaesthetic agents, but flumazenil 30 mg kg-1 potentiated propofol-induced anaesthesia. Flumazenil did not affect anaesthesia-induced EEG changes. Diazepam 5 mg kg-1 potentiated anaesthesia. Flumazenil antagonism of diazepam potentiation varied with anaesthetic agent: flumazenil 0.3 mg kg-1 antagonized diazepam action in halothane anaesthesia, but 30 mg kg-1 was required in propofol anaesthesia; this large dose was insufficient in thiamylal anaesthesia.
Murayama
T
T
Department of Anesthesia, Kyoto University Hospital, Japan.
Shingu
K
K
Ogawa
T
T
Tomoda
K
K
Shindo
K
K
Tamai
S
S
Mori
K
K
D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003975:Diazepam / Q000037:antagonists & inhibitors*; D004347:Drug Interactions; D004569:Electroencephalography / Q000187:drug effects*; D005442:Flumazenil / Q000494:pharmacology*; D006221:Halothane / Q000037:antagonists & inhibitors*; D008297:Male; D015742:Propofol / Q000037:antagonists & inhibitors*; D051381:Rats; D011919:Rats, Inbred Strains; D012890:Sleep / Q000187:drug effects; D013840:Thiamylal / Q000037:antagonists & inhibitors*
D013840:Thiamylal; D005442:Flumazenil; D003975:Diazepam; D006221:Halothane; D015742:Propofol