What is the maximum recommended dosage of lidocaine in a healthy adult?

• A. 3 mg/kg without a vasoconstrictor
• B. 5 mg/kg without a vasoconstrictor
• C. 7 mg/kg without a vasoconstrictor
• D. 10 mg/kg with a vasoconstrictor

Answer: (B)

The maximum recommended dosage of lidocaine in a healthy adult without a vasoconstrictor is 5 mg/kg. This dosage allows for effective local anesthesia while minimizing the risk of systemic toxicity. It takes into account the pharmacological properties of lidocaine, including its metabolism and elimination from the body.

Lidocaine is a commonly used amide local anesthetic known for its rapid onset and intermediate duration of action. By adhering to the 5 mg/kg limit, practitioners ensure that the medication can provide sufficient anesthesia while keeping safety a priority. Exceeding this dosage could lead to adverse effects such as CNS toxicity, resulting in symptoms like dizziness, seizures, or cardiovascular effects.

In contrast, if a vasoconstrictor was used, the maximum dosage could be increased due to the vasoconstrictor's ability to prolong the effects of lidocaine and reduce systemic absorption, but in this scenario without a vasoconstrictor, the 5 mg/kg limit is the established guideline for safe practice.