If amiodarone is unavailable, which drug is listed as an alternative for stable monomorphic VT per protocol?

• A. Lidocaine
• B. Procainamide
• C. Sotalol
• D. Adenosine

Answer: (B)

When a patient has a stable monomorphic VT, the goal is to terminate the tachycardia with an antiarrhythmic while keeping blood pressure and perfusion adequate. Amiodarone is a common first choice, but if it isn’t available, the protocol lists procainamide as the alternative.

Procainamide is a class IA antiarrhythmic. It works by blocking sodium channels and slowing conduction, which helps to terminate the wide-complex tachycardia and stabilize the rhythm in a controlled setting. It’s given intravenously, with careful monitoring of blood pressure, the QRS duration (to watch for excessive widening), and the QT interval (to minimize the risk of torsades de pointes). If a patient cannot receive procainamide due to hypotension or QT prolongation risk, or if they don’t respond, clinicians would proceed with other supported measures such as electrical cardioversion.

Adenosine is not appropriate for VT because it targets AV nodal conduction and is effective for certain narrow-complex tachycardias, not wide-complex VT. Lidocaine can be used in VT, especially in ischemic contexts, but the protocol often lists procainamide as the preferred alternative when amiodarone isn’t available. Sotalol is another antiarrhythmic option but requires careful monitoring and isn’t the standard alternative in this specific protocol.