Procainamide Overview and Mechanism of Action

Questions and Answers

What class of drug is procainamide?

Sodium channel blocker

What is the mechanism of action (MOA) of procainamide?

Block sodium ion channels in myocardial cells, reducing automaticity and slowing conduction of the action potential across the myocardium.

What is the most common route of administration for procainamide?

Oral XL

What are the routes available for procainamide? (Select all that apply)

IM Signup and view all the answers

What are the therapeutic levels of procainamide?

4-8 mcg/ml Signup and view all the answers

What are common adverse effects of procainamide?

Nausea, vomiting, abdominal pain, hypotension, and headache. Signup and view all the answers

What is the black box warning associated with procainamide?

Chronic administration may produce titer of antinuclear antibodies (ANA) and lupus-like syndrome may occur in 30-50% of patients. Signup and view all the answers

What are the contraindications for procainamide?

Severe AV block, severe heart failure, blood dyscrasias, and myasthenia gravis. Signup and view all the answers

What laboratory levels might procainamide increase?

AST, ALT, alkaline phosphatase, LDH, serum bilirubin. Signup and view all the answers

What is the treatment for procainamide overdose?

Reverse hypotension with vasopressors. Signup and view all the answers

Study Notes

Procainamide Overview

Class: Sodium channel blocker, effective for specific cardiac conditions.

Mechanism of Action (MOA)

Blocks sodium ion channels in myocardial cells.
Reduces automaticity and slows conduction of the action potential throughout the myocardium.
Results in slight delay in conduction, prolonging the refractory period, beneficial for suppressing dysrhythmias.
Broad-spectrum efficacy for various atrial and ventricular dysrhythmias.

Uses

Indicated primarily for life-threatening dysrhythmias.

Administration Routes

Most common: Oral Extended-Release (XL).
Other options: Intravenous (IV) and Intramuscular (IM).

Therapeutic Levels

Target range: 4-8 mcg/ml for effective treatment.

Adverse Effects

Common: Nausea, vomiting, abdominal pain, hypotension (HOTN), headache (HA).
High doses potentially cause central nervous system (CNS) issues like confusion and psychosis.

Black Box Warning

Prolonged use may trigger antinuclear antibodies (ANA).
Risk of lupus-like syndrome in 30-50% of patients on long-term therapy.
Usage should be limited to life-threatening dysrhythmias due to the potential to introduce new dysrhythmias or exacerbate existing ones.
Associated risks include agranulocytosis and bone marrow depression.

Contraindications

Not recommended for patients with severe atrioventricular (AV) block, severe heart failure (HF), blood dyscrasias, and myasthenia gravis.

Lab Interactions

May elevate enzyme levels: AST, ALT, alkaline phosphatase, LDH, and serum bilirubin.
Possible false positive results for Coombs tests and ANA titers.

Overdose Treatment

Hypotension resulting from overdose can be reversed using vasopressors.

Description

This quiz covers the essential aspects of Procainamide, a sodium channel blocker used for treating life-threatening dysrhythmias. It explores its mechanism of action, administration routes, therapeutic levels, and potential adverse effects. Test your knowledge on this critical medication and its implications in cardiac care.