Final answer:
Lidocaine can be used as an alternative medication to treat ventricular fibrillation in a 55-year-old patient in cardiac arrest when amiodarone is not available.
Step-by-step explanation:
In the event that the stock of amiodarone is depleted, lidocaine can be safely used as an alternative medication to treat ventricular fibrillation in a 55-year-old patient in cardiac arrest. Lidocaine is a class I antiarrhythmic medication that works by suppressing the electrical activity of the heart and stabilizing the cardiac rhythm.