WEBVTT
Kind: captions
Language: en
00:00:11.340 --> 00:00:17.800
Continuing on the dosing equation for oral admininstration.
00:00:17.940 --> 00:00:27.220
Now these two terms are equivalent if we assume same therapeutic concentration.
00:00:27.300 --> 00:00:34.380
Therefore, the equation is simplified to the second one.
00:00:34.460 --> 00:00:39.060
Therefore, the initial dose for the uremic patient
00:00:39.060 --> 00:00:46.320
is equal to the dose for the normal patient times a correction factor.
00:00:46.760 --> 00:00:54.120
Now, this equation is essentially the same as in the concentrate infusion
00:00:54.300 --> 00:01:04.240
except now we have one additional term, which is the ratio for the dosing interval Tau.
00:01:04.460 --> 00:01:08.500
So based on the dosing regimen equation
00:01:08.640 --> 00:01:12.400
if the dosing interval remains unchanged
00:01:12.900 --> 00:01:18.720
and the dose in renal failure should be reduced by a factor
00:01:18.720 --> 00:01:23.220
and that factor is the clearance ratio.
00:01:23.460 --> 00:01:28.160
Now on the other hand, if the dose is to remain the same
00:01:28.160 --> 00:01:31.920
then the dosing interval should be prolonged
00:01:32.240 --> 00:01:35.780
and It should be prolonged by a factor
00:01:35.780 --> 00:01:40.140
and that factor is also the clearance ratio.
00:01:40.140 --> 00:01:47.060
However, if those dose and the dosing frequency are to be adjusted concurrently.
00:01:47.160 --> 00:01:51.820
Then the dosing rate is to be reduced.
00:01:51.840 --> 00:01:59.040
so this is the dosing rate in uremic the dosing rate in normal.
00:01:59.100 --> 00:02:04.300
And that's the adjustment factor the clearance ratio
00:02:04.300 --> 00:02:14.160
However, this may be impractical to do to change dosing interval and the dose simultaneously.
00:02:14.160 --> 00:02:19.740
So to summarize the dosing regimen strategy in renal failure.
00:02:19.740 --> 00:02:22.340
Keep this same dosing interval,
00:02:22.340 --> 00:02:28.800
and reduce the dose, if the appropriate dosage of strength is available.
00:02:29.000 --> 00:02:35.220
Keep the same dose, prolong the dosing interval or change both.
00:02:35.340 --> 00:02:37.340
Adjust the dosing rate.
00:02:37.440 --> 00:02:44.940
Now the previous equation tell us to adjust dosing regimen based on clearance.
00:02:45.020 --> 00:02:50.460
Can we adjust dosing regimen based on K or half-life?
00:02:50.520 --> 00:03:00.200
because in the mission rate constant and half-life are more readily available than total clearance.
00:03:00.380 --> 00:03:03.940
so based on this equation,
00:03:03.940 --> 00:03:12.040
if volume distribution is the same for both the uremic patient
00:03:12.040 --> 00:03:17.660
and the patient with no more kidney function.
00:03:17.660 --> 00:03:22.020
Since clearance is the product of K times V
00:03:22.020 --> 00:03:31.760
so the equation to the left can be expended to the equation in the right.
00:03:31.900 --> 00:03:36.920
Now if we assume the same volume distribution.
00:03:37.040 --> 00:03:40.507
Then the volume distribution cancels out
00:03:40.507 --> 00:03:50.600
and that therefore we have dose in uremia is equal to dose in normal times a k ratio.
00:03:50.640 --> 00:03:56.800
And therefore we can use the K ratio to adjust dosing regimen.
00:03:56.900 --> 00:04:00.500
Assuming that the volume distribution is the same
00:04:00.500 --> 00:04:04.720
for renal failure patient and for patient with normal kidney function.