Table 2.
Summary of pharmacokinetic studies in obese children
| Drug | Dosing | Dosing weight |
Study design and sampling |
Population | Ages (years) | Obesity definition |
Findings in O compared with N |
|---|---|---|---|---|---|---|---|
| Cefazolin [30] | 25 mg/kg | Average of TBW and IBW |
P, SD, I | 5 O, 6 N | Median (range) O: 8.3 (1.8–9.3) |
Degree of obesity* [mean (StdDev)] O: 63% (18) |
Vss/TBW ↔ CL/TBW ↔ |
| Tobramycin [30] | 2 mg/kg | Vss/TBW ↓ CL/TBW ↔ |
|||||
| Gentamicin [31] | O < N | NA | R, Cmaxss, Cminss |
25 O, 25 N | Mean (SD) O/N: 9.9 (3.9) |
O: BMI 98%ile | V/TBW ↓ Cmaxss ↓ Ke, t1/2, Cminss ↔ |
| Vancomycin [32] | O = N | NA | R, Cmaxss, Cminss |
70 O or OV, 162 N |
O/OV: 2 to <6: n=22 6 to <12: n=29 12 to <18: n=19 |
OV: BMI >85 & <95%ile O: BMI >95%ile |
O/OV: Cminss ↑ %TT ↔ |
| Vancomycin [33] | O < N | NA | R, Cmaxss, Cminss |
24 O, 24 N | Mean (SD) O: 6.8(4.3) |
O: BMI 97%ile | t1/2, Cminss ↔ |
BMI: body mass index; CL: clearance; Cmaxss steady state peak concentration; Cminss steady state trough concentrations; I: intensive; IBW: ideal body weight; Ke: elimination rate constant; N: normal-weight; NA: not applicable; O: obese; OV: overweight;P: prospective; R: retrospective; SD: single dose; StdDev: standard deviation; t1/2: half-life; TBW: total body weight; TT: therapeutic trough; V: volume of distribution; Vss: steady-statevolume of distribution; %ile: percentile.
*
Degree of obesity was estimated from height and TBW using a nomogram [30].