Transfer of methylamphetamine and amphetamine into breast milk following recreational use of methylamphetamine

Abstract

Aims: To investigate the transfer of amphetamines into breast milk following their recreational use and estimate drug exposure for the breastfed infant.

Methods: Two breastfeeding mothers who were occasional recreational users of intravenous amphetamines were studied. A urine sample was collected 4 h after dose, and milk samples were collected over 24 h. Drug in urine was qualitatively identified by gas chromatography-mass spectrometry and quantification in milk was by high-performance liquid chromatography. Absolute infant dose via milk was estimated.

Results: The urines contained predominantly methylamphetamine together with smaller amounts of amphetamine. In the 24 h after dose, average concentrations in milk were 111 microg l(-1) and 281 microg l(-1) for methylamphetamine and 4 microg l(-1) and 15 microg l(-1) for amphetamine in cases 1 and 2, respectively. Absolute infant doses for methylamphetamine plus amphetamine (as methylamphetamine equivalents) were 17.5 microg kg(-1) day(-1) and 44.7 microg kg(-1) day(-1), respectively, for cases 1 and 2.

Conclusion: These limited data suggest that breastfeeding should be withheld for 48 h after recreational amphetamine use.

Figure 1

Drug concentration in milk vs. time for case 1 (a) and case 2 (b) following self-administration of one ‘point’ of methylamphetamine at zero time. methylamphetamine ("); amphetamine ()