Stavudine concentrations in women receiving postpartum antiretroviral treatment and their breastfeeding infants

Abstract

First-line antiretroviral treatment regimens in resource-limited settings used in breastfeeding mothers often include stavudine (d4T). Limited data describing d4T concentrations in breast milk are available. We analyzed d4T concentrations in 52 mother-infant pairs using ultra-performance liquid chromatography-tandem mass spectrometry (lower limit of quantification: 5 ng/mL in plasma, 20 ng/mL in breast milk). Median (interquartile range) d4T concentrations were 86 (36-191) ng/mL in maternal plasma, 151 (48-259) ng/mL in whole milk, 190 (58-296) ng/mL in skim milk, and <5 (<5 to <5) ng/mL in infant plasma. Although d4T is concentrated in breast milk relative to maternal plasma, the infant d4T dose received from breast milk is very small and not clinically significant.

Figure. Stavudine (d4T) concentrations in maternal plasma, breast milk, and infant plasma (PEPI-Malawi trial, 2004–2009)

The figure shows stavudine concentrations in maternal plasma, whole milk, skim milk and infant plasma from the PEPI-Malawi trial. Results are shown for 52 mother-infant pairs. For each sample type, the median (closed square), interquartile range (IQR, box), lower inner fence (first quartile [Q1] − [1.5 × IQR]) and upper inner fence (third quartile [Q3] + [1.5 × IQR], whiskers), outliers (greater than [Q3] + [1.5 × IQR], open circle) and extremes (greater than [Q3] + [3 × IQR], asterisk) are shown. Abbreviations: d4T: stavudine; N: number; PL: plasma; % BQL: percentage of samples that had d4T concentrations below the quantificationlimit of the assay (<5 ng/ml for plasma and <20 ng/ml for breast milk). Concentrations of d4T that were below the quantification limit (BQL) were assigned values of 2.5 ng/ml for plasma and 10 ng/ml for breast milk.