What is a significant risk associated with exceeding 400 mg of Prilocaine?

The significant risk associated with exceeding 400 mg of Prilocaine is the risk of methemoglobinemia. Prilocaine can metabolize to ortho-toluidine, which interferes with the ability of hemoglobin to carry oxygen, leading to a condition called methemoglobinemia. In this condition, the iron in hemoglobin is oxidized, meaning it can no longer bind oxygen effectively. Symptoms may include cyanosis, shortness of breath, and fatigue due to the reduced oxygen-carrying capacity of the blood. In severe cases, it can result in serious complications, highlighting the importance of dose regulation to avoid this adverse effect.

While other options may relate to various risks of local anesthetics, they do not specifically correlate with Prilocaine at doses exceeding 400 mg in the same manner as methemoglobinemia does. Understanding these risks is crucial for ensuring patient safety and effective management during procedures requiring local anesthesia.