This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
False about local anesthetics - 
Select and explain. 
A. Prilocaine is less toxic than lignocaine, B. Lignocaine is used as an antiarrhythmic, C. Mixture of ligno +- prilocaine is known as eutectic, D. Lidocaine is shorter acting than bupivacaine
A: Prilocaine is less toxic than lignocaine
Answer: A: Prilocaine is less toxic than lignocaine 
Explanation: Ans. is 'a' i.e., Prilocaine is less toxic than lignocaine o Prilocaine and Benzocaine can cause Methemoglobinemia. Therefore prilocaine is more toxic than lignocaine.o Lignocaine is also used as an antiarrhythmic.o A mixture of 2.5% lignocaine and 2.5 % prilocaine is known as Eutectic Mixture of local anesthetics (EMLA). This is unique topical preparation which can anesthetize intact skin.Local anestheticDuration of action without adrenalinewith adrenalineChloroprocaineLidocaineMepivacainePrilocaineBupivacaineRopivacaineDibucaine15-30 minutes45-60 minutes45 - 60 minutes45 - 60 minutes2-3 hours2-3 hours2.5- 3.5 hours30 - 90 minutes2 - 3 hours2 - 3 hours2 - 3 hours3 - 5 hours3-5 hours3.5 - 5.5 hours