The effect of sodium bicarbonate on propranolol-induced cardiovascular toxicity in a canine model.
OBJECTIVE
To evaluate the potential utility of sodium bicarbonate in an established model of acute propranolol toxicity.


METHODS
Two minutes after the completion of a propranolol infusion (10 mg/kg), a bolus of 1.5 mEq/kg of sodium bicarbonate solution (1 mEq/mL) followed by an infusion of 1.5 mEq/kg over the next 26 minutes (n = 6) or an equivalent timing and volume of 5% dextrose solution (n = 6) was administered in each dog. Targeted cardiovascular parameters included heart rate, mean arterial pressure, left ventricular dP/dtmax, and QRS interval.


RESULTS
Propranolol infusion significantly depressed heart rate (p < 0.0001), mean arterial pressure (p < 0.0001), dP/dtmax (p < 0.0001) and prolonged the QRS interval (p < 0.0001). Sodium bicarbonate failed to significantly improve these targeted parameters when compared to control animals.


CONCLUSIONS
In this canine model of propranolol toxicity, intravenous sodium bicarbonate appears to be an ineffective single therapy. Furthermore, these results may suggest a different mechanism of sodium channel blockade for propanolol than that of type IA antiarrhythmic agents.
Georgetown University, Washington, DC, USA.
J N
JN
Love
J M
JM
Howell
J T
JT
Newsome
D F
DF
Skibbie
L W
LW
Dickerson
K J
KJ
Henderson
D000818:Animals; D001639:Bicarbonates / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000139:chemically induced* / Q000188:drug therapy*; D004195:Disease Models, Animal; D004285:Dogs; D004562:Electrocardiography; D006329:Heart Conduction System / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D007262:Infusions, Intravenous; D011041:Poisoning / Q000188:drug therapy; D011433:Propranolol / Q000008:administration & dosage / Q000633:toxicity*; D012964:Sodium / Q000097:blood; D017693:Sodium Bicarbonate / Q000008:administration & dosage*; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000187:drug effects
D001639:Bicarbonates; D017693:Sodium Bicarbonate; D012964:Sodium; D011433:Propranolol