Rowland and Tozer provided guidance for developing a multiple dose drug regimen.
Parameters:
(1) therapeutic index (TI)
(2) drug half-life in hours
|
TI |
half-life in hours |
Dosage Interval |
Loading (First) Dose |
Other |
|
low |
< 0.5 |
NA |
NA |
use a closely monitored infusion |
|
|
0.5 to 3 |
NA |
NA |
use an infusion |
|
|
3 to 8 |
1 half-life |
1 to 2 times maintenance |
consider controlled release |
|
|
8 to 24 |
0.5 to 1 half-lives |
2 to 4 times maintenance |
|
|
|
> 24 |
< 1 half life |
> 2 times maintenance |
slow reversal once toxic |
|
moderate to high |
< 0.5 |
NA |
NA |
constant rate administration |
|
|
0.5 to 3 |
3 to 6 half-lives |
none ( 1 time maintenance) |
|
|
|
3 to 8 |
1 to 3 half-lives |
1 to 2 times maintenance |
|
|
|
8 to 24 |
1 half-life |
2 times maintenance |
|
|
|
> 24 |
<= 1 half-life |
> 2 times maintenance |
once daily or less often |
Specialty: Toxicology, Emergency Medicine, Critical Care
ICD-10: ,
