Inhibitory effects of landiolol and nicardipine on thiopental-induced yawning in humans.
OBJECTIVE
Either the calcium (Ca(2+))-channel blocker nicardipine or the beta(1)-adrenoceptor antagonist landiolol may be intravenously (IV) administered to reduce the hemodynamic responses to tracheal intubation. In this study, we examined the effects of these drugs on the yawning response elicited by intravenous thiopental in humans.


METHODS
After Institutional Review Board approval, 180 consenting American Society of Anesthesiologists (ASA) I or II patients undergoing elective surgery were recruited. In a double-blind, randomized design, three groups of 60 patients each received one of the following intravenous injections: (1) landiolol 0.1 mg/kg (L-group), (2) nicardipine 0.02 mg/kg (N-group), or (3) saline (S-group). In all patients, anesthesia was subsequently induced IV with 4 mg/kg thiopental. Thereafter, the occurrence of the yawning response (characterized by mouth opening) was continuously assessed as the only clinical endpoint for 1 min. Throughout the study, mean arterial blood pressure and heart rate were also recorded at 1-min intervals.


RESULTS
The incidence of the yawning response was lower in both the L-group (6.7%) and the N-group (16.7%) than in the S-group (46.7%) (each, P < 0.01).


CONCLUSIONS
Prior intravenous administration of either a Ca(2+)-channel blocker or a beta(1)-adrenoceptor antagonist can greatly reduce the thiopental-induced yawning response in humans.
Oshima
Tsutomu
T
Department of Anesthesia, Gifu Red Cross Hospital, Gifu, 502-8511, Japan. tsutomu.oshima@jfcr.or.jp
Murakami
Tatsuo
T
Saitoh
Yuhji
Y
Yokota
Miyuki
M
Kasuya
Yoshiko
Y
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000494:pharmacology*; D009529:Nicardipine / Q000494:pharmacology*; D013874:Thiopental / Q000008:administration & dosage / Q000009:adverse effects; D014508:Urea / Q000031:analogs & derivatives* / Q000494:pharmacology; D015000:Yawning / Q000187:drug effects* / Q000502:physiology
D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers; D006993:Hypnotics and Sedatives; D009025:Morpholines; C077049:landiolol; D014508:Urea; D009529:Nicardipine; D013874:Thiopental