What is use dependence?

What is use dependence?

Use Dependence and Reverse-Use Dependence Drugs with high use (frequency) dependence bind more avidly to the ion channels during faster heart rates and therefore exert more sodium channel blockade during tachycardia.

Which drug is used as antiarrhythmic agent?

amiodarone (Cordarone, Pacerone) flecainide (Tambocor) ibutilide (Corvert), which can only be given through IV. lidocaine (Xylocaine), which can only be given through IV.

What is reverse use dependence?

Reverse use dependence is the effect where the efficacy of the drug is reduced after repeated use of the tissue. This contrasts with (ordinary) use dependence, where the efficacy of the drug is increased after repeated use of the tissue.

What is the purpose of antiarrhythmic drugs?

The ultimate goal of antiarrhythmic drug therapy is to restore normal rhythm and conduction. When it is not possible to revert to normal sinus rhythm, drugs may be used to prevent more serious and possibly lethal arrhythmias from occurring.

What is use dependence drugs?

Background: Type I antiarrhythmic drugs block the cardiac sodium channel in a use-dependent fashion. This use-dependent behavior causes increased drug binding and consequently increased sodium channel blockade at faster stimulation rates.

What is a use dependence phenomenon of sodium channel blockers?

Differential block of sodium channels in closed, open or inactive states by antiarrhythmic drugs can result in use-dependent block, which is an important characteristic for efficacy during pathophysiological processes characterized by rapidly firing action potentials (such as during cardiac arrhythmias).

Is amlodipine an antiarrhythmic?

Dihydropyridines, like amlodipine, nicardipine, and nifedipine, are highly selective for calcium channels on the vascular smooth muscle tissue; so they’re primarily used to treat hypertension. On the other hand, non-dihydropyridines are the class IV antiarrhythmics and they include verapamil and diltiazem.

What are Class 1 antiarrhythmics used for?

Class Ia antiarrhythmic drugs Class Ia drugs block repolarizing potassium channels, prolonging the refractory periods of fast-channel tissues. On the ECG, this effect is reflected as QT-interval prolongation even at normal rates. . The primary indications are supraventricular and ventricular tachycardias.

What drugs are potassium channel blockers?

Potassium Channel Blockers

Is amiodarone an AV nodal blocking agent?

Cardiac toxicity. Amiodarone by blocking the calcium channel activity can cause sinus bradycardia and AV nodal block in 5% of patients. Hypotension may occur when concentrated Amiodarone hydrochloride injection is given by the intravenous route.

Which drug is considered a Class 1A antiarrhythmic drug?

Antiarrhythmics, Class Ia