What are common signs of CNS depression due to local anesthetic toxicity?

Drowsiness and coma are common signs of central nervous system (CNS) depression that can result from local anesthetic toxicity. When local anesthetics are administered inappropriately or when there is an overdose, they can cross the blood-brain barrier and lead to an array of neurological symptoms. The initial symptoms often include sedation and drowsiness, which can progress to a state of coma as the level of CNS depression increases. This escalation occurs because local anesthetics inhibit neuronal excitability, ultimately leading to decreased responsiveness and consciousness. As the toxicity progresses, it can compromise respiratory function and may lead to life-threatening conditions, but the hallmark signs of CNS involvement in the early stages are notably drowsiness followed by possible coma.