To determine infant exposure to 6-thioguanine and 6-methylmercaptopurine nucleotides (6-TGN and 6-MMPN, respectively) during maternal use of azathioprine in breastfeeding.
Department of Clinical Pharmacology, Christchurch Hospital and Christchurch School of Medicine, Christchurch, New Zealand. sharon.gardiner@cdhb.govt.nz