TABLE 3.

Rifampin pharmacokinetic parameters by age, nutritional status, prematurity, HIV status, ethnicity, gender, formulation, and dose (n = 39)

Variable	Parameter data for:
	Cmax (μg/ml)			AUC0–8 (μg · h/ml)			t1/2 (h)a
	No. evaluated	Mean (SD) value	P	No. evaluated	Mean (SD) value	P	No. evaluated	Mean (SD) value	P
Age at PK sampling, mo
0–6	20	2.89 (2.16)		20	12.78 (9.72)		17	2.17 (0.70)
7–12	19	2.92 (2.24)	0.975	19	11.43 (9.63)	0.664	19	1.95 (0.88)	0.425
Nutritional status on day of PK
≥−2.0	21	2.65 (1.94)		21	10.60 (8.20)		20	2.02 (0.78)
<−2.0	18	3.21 (2.44)	0.429	18	13.90 (10.93)	0.289	16	2.08 (0.84)	0.830
Prematurity
Term (≥38 wk)	24	2.73 (1.90)		24	11.46 (8.65)		23	1.99 (0.84)
Premature (<37 wk)	15	3.18 (2.60)	0.538	15	13.18 (11.12)	0.593	13	2.17 (0.73)	0.520
HIV status
HIV infected	5	3.67 (3.31)		5	16.46 (15.00)		5	2.27 (1.14)
HIV uninfected	34	2.79 (2.00)	0.404	34	11.48 (8.66)	0.283	31	2.02 (0.75)	0.522
Ethnicity
African	29	3.00 (2.37)		29	12.04 (10.20)		28	1.88 (0.64)
Mixed race	10	2.63 (1.52)	0.644	10	12.37 (7.94)	0.926	8	2.67 (1.04)	0.011
Gender
Female	13	3.27 (2.39)		13	13.00 (10.01)		13	1.75 (0.57)
Male	26	2.72 (2.08)	0.468	26	11.68 (9.52)	0.692	23	2.22 (0.87)	0.088
Rifampin formulation
Formulation 1	14	4.13 (2.35)		14	16.77 (10.50)		14	2.07 (0.84)
Formulation 2	25	2.22 (1.77)	0.007	25	9.52 (8.11)	0.021	22	2.04 (0.79)	0.918
Rifampin dose, mg/kg
10–15	17	2.74 (2.34)		17	10.86 (10.01)		17	1.91 (0.71)
15–20	22	3.03 (2.09)	0.691	22	13.10 (9.34)	0.447	19	2.17 (0.87)	0.340

^at_1/2, half-life of the drug.