TOPICS: Local anesthetics, esters, one "i" in their names, procaine, tetracaine, benzocaine, chloroprocaine, methemoglobinemia, amides, two "i"s in their names, lidocaine, mepivacaine, bupivacaine, ropivacaine, severe cardiovascular toxicity, give amides if allergic to esters, block sodium channels, small diameter myelinated, small diameter unmyelinated, large myelinated, large unmyelinated, pain, temperature, touch pressure, epinephrine to enhance local anesthetic effects, tertiary amines, uncharged, alkaline anesthetics, minor surgical procedures, spinal anaesthesia, metallic taste, perioral numbness, anxiety, seizures, hypertension, hypotension, arrhythmia