Choosing the right local anesthetic starts with understanding the chemistry behind it. This course breaks down ester vs amide local anesthetics—how their structures drive metabolism, allergy risk, and duration of action—and revisits the sodium channel–blocking mechanisms that underpin every block you perform. You’ll compare onset, duration, absorption, and toxicity profiles across common agents like lidocaine, bupivacaine, procaine, and tetracaine so you can match the drug to the patient, procedure, and risk profile with greater precision and confidence in daily practice.