When a patient has received one dose of lidocaine, what should be the subsequent dosage the patient receives?

The appropriate subsequent dosage of lidocaine after an initial dose is based on safety and achieving therapeutic levels for effective management of arrhythmias. When administering lidocaine, the initial intravenous (IV) dose is typically 1 to 1.5 mg/kg, and if the patient requires additional dosing, the standard recommendation is to give a maintenance dose that falls within the range of 0.5 to 0.75 mg/kg.

This dosage range is chosen to ensure that the drug maintains its efficacy in controlling arrhythmias while minimizing the risk of toxicity, especially considering lidocaine's narrow therapeutic index. Administering a higher dose could lead to central nervous system toxicity or cardiovascular side effects, which is why the lower range is favored for subsequent dosing after the first administration. This careful titration ensures that the patient receives effective treatment without exceeding safe limits, making the selected dosage the most suitable option in this scenario.