Which class includes medications such as Lidocaine HCl (Xylocaine) used to treat cardiac arrhythmias?

Which class includes medications such as Lidocaine HCl (Xylocaine) used to treat cardiac arrhythmias?

• A. Antibiotic
• B. Antiarrhythmic
• C. Vasodilator
• D. Anticonvulsant

Answer: (B)

The main concept here is that antiarrhythmic drugs are used to correct abnormal heart rhythms by altering the heart’s electrical activity. Lidocaine HCl (Xylocaine) is a classic example of an antiarrhythmic drug, specifically a sodium-channel blocker classified in the class I family. It is used to treat certain ventricular arrhythmias by dampening excessive electrical activity in the ventricles. Mechanistically, lidocaine blocks fast sodium channels during depolarization, which lowers the rate of rise of the action potential and reduces automaticity in ventricular tissue. This effect is especially helpful in ischemic or injured tissue, where abnormal impulses tend to originate, helping to prevent dangerous rhythms. This is best explained by comparing to the other categories: antibiotics fight infections, vasodilators widen blood vessels to lower blood pressure or improve blood flow, and anticonvulsants control seizures. None of those classes is primarily used to treat cardiac arrhythmias, whereas antiarrhythmics are specifically used to stabilize heart rhythm.

The main concept here is that antiarrhythmic drugs are used to correct abnormal heart rhythms by altering the heart’s electrical activity. Lidocaine HCl (Xylocaine) is a classic example of an antiarrhythmic drug, specifically a sodium-channel blocker classified in the class I family. It is used to treat certain ventricular arrhythmias by dampening excessive electrical activity in the ventricles.

Mechanistically, lidocaine blocks fast sodium channels during depolarization, which lowers the rate of rise of the action potential and reduces automaticity in ventricular tissue. This effect is especially helpful in ischemic or injured tissue, where abnormal impulses tend to originate, helping to prevent dangerous rhythms.

This is best explained by comparing to the other categories: antibiotics fight infections, vasodilators widen blood vessels to lower blood pressure or improve blood flow, and anticonvulsants control seizures. None of those classes is primarily used to treat cardiac arrhythmias, whereas antiarrhythmics are specifically used to stabilize heart rhythm.