Pharmacogenomics: why standard codeine doses can have serious toxicities or no therapeutic effect.

T hree children died in August 2012 after receiving usual doses of codeine for postoperative pain following a tonsillectomy and/or adenoidectomy (U.S. Food and Drug Administration [FDA], 2013a). Those incidents, combined with a case report of a breast-feeding infant who died in 2005 of an apparent overdose after the mother received a standard dose of codeine for episiotomy pain (Health Sciences Authority, 2009; Koren, Cairns, Chitayat, Gaedigk, & Leeder, 2006), heighten the need to understand the pharmacogenomics of codeine metabolism.