Which side effect is an early sign of local anesthetic overdose?

Dizziness and anxiety are indeed early signs of local anesthetic overdose. Local anesthetics work by blocking nerve conduction in the area they are administered, but if the concentration of the drug becomes too high in the bloodstream, it can lead to central nervous system effects. The initial manifestations of systemic toxicity typically include symptoms related to the central nervous system, such as anxiety, agitation, dizziness, and tremors. These signs occur before more severe effects, such as seizures or loss of consciousness, develop. Monitoring for these early symptoms is critical in preventing progression to more serious complications associated with local anesthetic overdose.

While bradycardia and prolonged bleeding can occur with local anesthetics, they are generally associated with later stages or specific complications rather than being early signs of overdose.