An ambiguous label led a nurse to mistake a 10 mg methadone tablet for a 20 mg tablet. The drug is packaged in unit-dose blister packs numbered sequentially with a white number on a black background. In this case, the number 20 immediately preceded the dosage information: Tablet USP 10 mg (see photo). The manufacturer, Boehringer Ingelheim, plans to revise the label format.