Pharmacokinetics of XXXX : experience with a sustained intravenous infusion regimen.

@entity1 @entity1855 @entity551 @entity943
Disappearance kinetic characteristics of @entity1855 were determined in 9 @entity1 after a single intravenous dose. From the pharmacokinetic variables determined, we designed an intravenous regimen to maintain a plasma @entity1855 concentration of 150 ng/ml consisting of (1) a loading bolus (10 mg over 2 minutes), followed by (2) a rapid loading infusion (0.375 mg/min) for 30 minutes, and finally (3) a maintenance infusion (0.125 mg/min). We tested this regimen in 7 @entity1 for 2 to 12 hours, and found it to be safe and to produce stable prolongation of the P-R interval. @entity1855 concentration was highest immediately after the bolus administration and was prevented from falling below 67 ng/ml by the rapid infusion. Maintenance concentration remained between 77 and 156 ng/ml for all @entity1 , and averaged 122 ng/ml. Transient and slight @entity551 and sinus cycle length occurred coincident with the maximum @entity1855 concentration. Maximum P-R prolongation lagged behind peak plasma concentration but was sustained for the duration of the infusion. Prolongation of the P-R interval was not significantly different at the end of the infusion from that 90 minutes after the start of the regimen. No @entity1 demonstrated significant side effects, @entity943 , or clinically important @entity551 . Although the specified regimen produced a final concentration averaging 125 ng/ml, it is predicted that infusion regimens producing other plasma concentrations can be similarly devised by changing the bolus, rapid loading infusion, and maintenance infusion doses in proportion to the desired final plasma concentration.
