IV potassium is measured in Milliequivilents. The lethal effect is dependent on the rate and concentration. A safe rate for IV potassium chloride is 10 Meq/ hour. If you increase that, the patient should be on telemetry. In life threatening emergencies, 40 meq's can be injected in a short period of time but not less than 1 hour. More than that can stop the heart. In Kevorkians' case, I wonder how many people would have opted for death if they had their pain controlled first.