indecainide

Action and Spectrum

Actions and Spectrum 

Actions: 

indecainide exerts its antiarrhythmic effects primarily by blocking sodium channels in cardiac cells. Sodium channels are crucial in initiating and conducting electrical signals within the heart. By blocking these channels, indecainide decreases the influx of sodium ions into cardiac cells during an action potential, which can help prevent abnormal electrical impulses that contribute to arrhythmias. 

Spectrum: 

indecainide is primarily used to treat ventricular arrhythmias, specifically for managing symptomatic premature ventricular contractions (PVCs) and ventricular tachycardia (VT). Ventricular arrhythmias are abnormal rhythms originating in the ventricles, the heart’s lower chambers. 

Drug Interaction

Adverse Reaction

Frequency Defined 

Proarrhythmia 

QRS prolongation 

Conduction disturbances 

Gastrointestinal disturbances 

CNS effects 

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution: 

Contraindications: 

• Hypersensitivity 
• Severe atrioventricular block 
• Heart failure 
• Hypotension 
• Brugada Syndrome 
• Cardiogenic shock 

Cautions: 

• Mild to moderate allergies 
• Asthma 
• Dehydration 
• Diabetes 
• Elderly patients 
• Pregnancy 
• Breastfeeding 

Pregnancy / Lactation

Pregnancy consideration:  

Pregnancy Category: C. 

Breastfeeding warnings:  

indecainide is excreted in small amounts in breast milk; hence, utilize it cautiously. 

Pregnancy category: 

Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology:  

indecainide exerts its effects primarily by blocking sodium channels in cardiac cells. Sodium channels are responsible for the rapid depolarization phase of the cardiac action potential. By blocking these channels, indecainide slows the rate of sodium influx into cardiac cells during an action potential, leading to a decreased rate of rise of the action potential and a decreased conduction velocity. 

Pharmacodynamics: 

indecainide’s sodium channel blockade slows conduction through the heart and prolongs the action potential duration, particularly the QRS complex on the electrocardiogram (ECG). This leads to a widening of the QRS complex. The increased duration of the action potential and refractory period can help prevent the re-entry of electrical signals that can lead to certain arrhythmias. 

Pharmacokinetics: 

Absorption 

indecainide is rapidly absorbed from the gastrointestinal tract after oral administration. 

Distribution 

indecainide, including cardiac tissues, is distributed throughout the body, where its antiarrhythmic effects are exerted. 

indecainide has high protein binding, primarily to plasma proteins like albumin. 

Metabolism 

indecainide undergoes metabolism primarily in the liver through various pathways, including oxidation and acetylation. 

Elimination and excretion 

The elimination half-life is approximately 10 hours 

It is excreted through the kidneys 

Adminstartion

Administration: 

indecainide is typically administered orally in the form of tablets or capsules. The instructions for administering indecainide can vary based on the individual patient, the prescribed dosage, and the healthcare provider’s recommendations. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: indecainide 

Pronounced as: in-dek-ain-ide 

Why do we use indecainide? 

indecainide is used as an antiarrhythmic medication to treat irregular heart rhythms, particularly ventricular arrhythmias. Its use primarily focuses on managing arrhythmias that originate in the ventricles, which are the heart’s lower chambers.