Interaction between betamethasone and vecuronium.
A possible interaction between betamethasone and vecuronium was examined in 20 rat phrenic nerve-hemidiaphragm preparations. Ten preparations were bathed in a physiological solution with betamethasone 1 mumol litre-1 added and, after a 30-min period were exposed to vecuronium at concentrations of 4, 6, 8 and 10 mumol litre-1 with vecuronium free washings between each exposure. Ten control experiments were performed also using a betamethasone-free bathing solution. In comparison with control, the betamethasone group had significantly (P = 0.0008) less depression of muscle contraction (twitch) force at all concentrations of vecuronium. The calculated ED50 (50% depression of muscle contraction force) was 5.65 mumol litre-1 for controls and 7.39 mumol litre-1 for betamethasone-pretreated preparations. This study confirms our previous clinical observations that an interaction occurs between vecuronium and betamethasone which is characterized by resistance to neuromuscular block.
Section of Anaesthesia, Wellington School of Medicine, New Zealand.
S M
SM
Parr
B J
BJ
Robinson
D
D
Rees
D C
DC
Galletly
D000818:Animals; D001623:Betamethasone / Q000494:pharmacology*; D003864:Depression, Chemical; D003964:Diaphragm / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009924:Organ Culture Techniques; D010791:Phrenic Nerve / Q000187:drug effects*; D051381:Rats; D014673:Vecuronium Bromide / Q000494:pharmacology*
D014673:Vecuronium Bromide; D001623:Betamethasone