Myocardial bethanidine kinetics after single-dose intravenous infusion: correlation with plasma kinetics in closed-chest dogs.
Myocardial and plasma bethanidine kinetics were determined in five dogs after an intravenous dose of 6 mg/kg/10 min. Serial myocardial drug concentrations were determined from endomyocardial samples obtained by transvenous biopsies between 15 min and 72 h. Tissue and plasma samples were assayed by gas-liquid chromatography. Bethanidine was rapidly concentrated in myocardium within 15 min. Tissue/plasma drug ratios averaged 131 +/- 35 between 15 min and 2 h and 53 +/- 10 between 6 and 48 h. Parallel biexponential decay then occurred for both tissue and plasma compartments; the terminal half-life approximated 16 h. Based on differences in rates of myocardial drug kinetics, the cardiac antifibrillatory effects of bethanidine may occur more rapidly than those of bretylium.
J L
JL
Anderson
M
M
Anastasiou-Nana
V D
VD
Dayton
R N
RN
Creagar
R L
RL
Jensen
G J
GJ
Wright
D000818:Animals; D001627:Bethanidine / Q000008:administration & dosage / Q000378:metabolism*; D002849:Chromatography, Gas; D004285:Dogs; D006146:Guanidines / Q000378:metabolism*; D006207:Half-Life; D007275:Injections, Intravenous; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism*
D006146:Guanidines; D001627:Bethanidine