What is a common side effect of IV vitamin K administration?

• A. Nausea and vomiting
• B. Dyspnea and chest tightness
• C. Hypertension
• D. Fever

Answer: (B)

When vitamin K is given intravenously, it can trigger an immediate hypersensitivity–like reaction. The most characteristic and commonly reported side effect is dyspnea with chest tightness occurring during the infusion, sometimes with mild flushing or low blood pressure. This reaction is more associated with IV administration than with other routes, and slowing or stopping the infusion typically helps the symptoms resolve. Nausea and vomiting can happen with many drugs but are less specific to IV vitamin K, and hypertension or fever are not typical features of this IV reaction. If symptoms appear, stop the infusion and provide supportive care; treat as needed for bronchospasm or anaphylactoid reaction, with oxygen and escalation of care if necessary.