Table 1.

ARV concentrations in maternal plasma and breast milk^a

ARV	Median maternal plasma concentration during third trimester of pregnancy, μg/ml	Median maternal plasma concentration at 1 month postpartum, μg/ml	Median maternal breast milk concentration at 1 month postpartum, μg/ml	Median maternal breast milk to plasma ratio at 1 month postpartumb
LPVc	Capsule: 6.18	Capsule: 7.12	0.06	0.007
	Tablet: 4.85	Tablet: 10.75
	Total: 5.51	Total: 8.29
ABCd	–	0.067	0.057	0.85
NVP	–	6.71e	1.83e	0.27
3TC	–	0.19e	0.14e	0.74
ZDV	–	–	0.007e	–

^aHalf-maximal inhibitory concentration (IC₅₀) for lopinavir (LPV)=0.0019 μg/ml, IC₅₀ for abacavir (ABC)=0.07 μg/ml, IC₅₀ for nevirapine (NVP)=0.024 μg/ml, IC₅₀ for lamivudine (3TC)=0.55 μg/ml, IC₅₀ for zidovudine (ZDV)=0.005 μg/ml [10,15].

^bMedian of individual breast milk to plasma ratios for each participant.

^cResults exclude women with peak below detectable limit (two antepartum plasma samples, eight postpartum milk samples).

^dResults exclude women with peak below detectable limit (six plasma samples, five milk samples).

^eResults exclude women with detectable peaks sampled outside of a 10–18 h range from last dose (four breast milk 3TC, one plasma 3TC; one breast milk NVP, one plasma NVP; two breast milk ZDV). ARV, antiretroviral.