Table 3.

Erythromycin breath test results in study 2 in the absence (baseline) and presence of three treatments: ritonavir alone (period 1), mefloquine alone (period 2), and ritonavir with mefloquine (period 3).

		Treatment		anova for longitudinal design
Parameter	Baseline	Ritonavir alone (Period 1)	Mefloquine alone (Period 2)	Ritonavir and mefloquine (Period 3)	Pooled Intra-subject %CV	Pooled Inter-subject %CV
%M h−1	2.38 ± 0.68	0.094 ± 0.017	2.39 ± 0.70	0.10 ± 0.02	17.5	7.7
Point estimate (90% CI)†		4.2 (3.6–4.9)‡	101 (86.2–118)	4.6 (3.9–5.4)‡
%M min−1	0.046 ± 0.014	0.001 ± 0.0003	0.046 ± 0.014	0.001 ± 0.0003	23.3	10.1
Point estimate (90% CI)†		2.4 (1.9–2.9)‡	101 (81.5–124)	2.7 (2.2–3.3)‡

%M h⁻¹ and %M min⁻¹, percentage of administered carbon-14 exhaled as ¹⁴ CO₂ over the first hour and exhaled per minute as ¹⁴ CO₂ at 20 min, respectively, after injection of 3 µCi of [¹⁴C-N-methyl]erythromycin; CI, confidence interval.

*Erythromycin breath test was administered in the absence of drugs on the day before the start of study 2 (baseline), at 4 h after a single dose of 200 mg ritonavir alone (period 1), at 13 h after the last (5th) 250 mg dose of mefloquine alone (period 2), and at 4 h after a single dose of 200 mg ritonavir in the presence of the last 250 mg dose of mefloquine (period 3). Values of treatment means are expressed as arithmetic mean±s.d. (n = 12, baseline and period 1; n = 11, periods 2 and 3).

^†Percentage ratio of the least-squares geometric treatment mean in period 3, 2 or 1 relative to that of the baseline treatment. Confidence intervals were calculated with use of Dunnett's critical t-value.

^‡Significant by Dunnett's test at the 5% level (P < 0.020).