Which of the following is an early sign of local anesthetic toxicity?

• A. Tremors
• B. Numbness of lips
• C. Coma
• D. Seizures

Answer: (B)

Early signs of local anesthetic toxicity are sensory changes around the mouth, reflecting the first effects of rising drug levels on the nervous system. The numbness of the lips is the classic early indicator because the perioral region is highly exposed to the anesthetic during injections, and patients notice tingling or loss of sensation there before more systemic symptoms appear. As the toxicity progresses, the CNS may become irritable with symptoms like tremors, then more severe events such as seizures, and finally possible coma if levels remain high. So lip numbness stands out as the earliest, most reliable sign, while tremors, seizures, and coma indicate advancing toxicity rather than the initial stage.