TABLE 3.

Pharmacokinetic parameters of clarithromycin and 14-OH-clarithromycin for 11 subjects receiving regimen A^a

Drug	AUC0–τ (μg · h/ml)			Mean % change in AUC0–τ between days 14 and 42 (P value)	Cmax (μg/ml)			Mean % change in Cmax between days 14 and 42 (P value)	Tmax (h)			Mean % change in Tmax between days 14 and 42 (P value)
	Day 14	Day 15	Day 42		Day 14	Day 15	Day 42		Day 14	Day 15	Day 42
Clarithromycin	36.5 ± 15.0	35.5 ± 15.8	16.6 ± 5.4	−44 ± 37 (0.003)	5.7 ± 2.4	4.6 ± 1.7	2.8 ± 1.0	−41 ± 35 (0.003)	3.0 ± 2.3	3.2 ± 2.2	3.5 ± 3.2	34 ± 100 (0.287)
14-OH-Clarithromycin	9.1 ± 3.4	9.2 ± 3.7	13.4 ± 5.0	57 ± 51 (0.004)	1.1 ± 0.4	1.0 ± 0.4	1.7 ± 0.6	69 ± 49 (<0.001)	3.6 ± 2.8	3.1 ± 2.4	4.6 ± 3.6	52 ± 106 (0.136)
Rifabutin		8.6 ± 8.2b	6.1 ± 1.9			0.59 ± 0.33	0.54 ± 0.19			3.7 ± 1.1	3.8 ± 3.4
25-O-Desacetyl-rifabutin		2.3 ± 1.2b	1.5 ± 0.7			0.10 ± 0.06	0.12 ± 0.06			5.3 ± 1.2	4.4 ± 3.0

^aStudy day 14 is steady state for clarithromycin alone, day 15 is the first day that rifabutin was added to the regimen, and day 42 is steady state for both drugs. All values are means ± standard deviations. 

^bThe AUC reported for rifabutin and its metabolite on day 15 represents AUC_0–∞.