A nurse notes that a medication order reads 'give 10U insulin.' Why is this order potentially unsafe?

The abbreviation 'U' for UNITS is on the 'DO NOT USE' list because it can be MISREAD — 'U' can look like a 0 (making '10U' read as '100') or a 4, leading to dangerous dosing errors. The word 'UNITS' should be written out in full. NCLEX safe care/medication safety. OTHER ERROR-PRONE ABBREVIATIONS to avoid: 'IU' (international units — write out); 'QD'/'QOD' (write 'daily'/'every other day'); trailing zeros (write '1 mg' not '1.0 mg' — the decimal can be missed); lack of leading zero (write '0.5 mg' not '.5 mg' — the decimal can be missed). The nurse should CLARIFY unsafe orders. Knowing the dangerous abbreviations (especially 'U' for units) is a commonly tested medication-safety concept.