Figure 32. Plots of the cumulative amounts (e U, p g) of metabolite (M) excreted
in urine against area under the plasma concentration-time curve
(AUCt, yg.min/ml) at the time of urine collection interval in accordance with
the equation (30):
EU = [ AUCt AUCq ]
where AUCq is the area under the plasma concentration time curve at £ U=0. a) For
the 1.4171 mg/kg IV bolus dose of buprenorphine in dog A, Study #1, the estimated
renal clearance for M was 11.79 ml/min for the time period between 153-700 min.
The estimated renal clearance during the first 153 min was 1.94 ml/min (see table
2). b) For the 1.6369 mg/kg IV bolus dose of buprenorphine in dog B, Study #2, the
estimated initial renal clearance of M was 3.6 ml/min. c) For the 1.2023 mg/kg IV
bolus dose of buprenorphine in dog C, Study #4, the estimated renal cleamace of M
was 11 ml/min for the time period 158-1270 min. However, for the initial 158 min,
the renal clearance was 4.4 ml/min (Intercept = -30.4). d) For the 1.439 mg/kg IV
bolus dose of buprenorphine in dog C, Study #5, the estimated renal clearance was
0.26 ml/min for the time period 75-2630 min. In the same dog, the estimated renal
clearance for the first 75 min vas 0.98 ml/min (intercept=-9.2).