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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Which of the following is a Class Ib drug?
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The correct answer is  Class 1 Drugs with local anesthetic action block sodium channels and reduce the sodium current, INa. They are the oldest group of antiarrhythmic drugs and are still widely used.Drugs belonging to Subgroup 1B1) Lidocaine2) MexiletineReference: Katzung Pharmacology; 13th edition; Chapter 14; Agents Used in Cardiac Arrhythmias