Potassium overdose using an oral solution: potassium element expressed in grams as a packaging flaw contributing to medication error.

Drug packaging contributes to the harm-benefit balance of a treatment. Poorly designed packaging can lead to drug misuse with serious consequences. We report a potassium double dose medication error concerning an oral solution. It was triggered by a packaging flaw related to the dosage indicated on the box, expressed for both potassium salt and elemental potassium. Standardizing the units used on packaging and for prescriptions, by using millimoles, could be a solution to avoid this type of medication error.