Why must intravenous potassium never be given by rapid bolus?

Intravenous potassium must never be given by rapid bolus push because a sudden surge of potassium into the bloodstream can cause fatal cardiac arrhythmias including ventricular fibrillation and cardiac arrest. Potassium must always be diluted and infused slowly, typically no faster than 10 milliequivalents per hour through a peripheral line or 20 milliequivalents per hour through a central line with cardiac monitoring. The infusion site must be monitored because potassium is a vesicant that causes severe pain and tissue damage if it infiltrates. ---