House
Sign inCreate account
Drug lookup
Drug reference

ibutilide

K+ Channel Blocker (Class III) · Antiarrhythmic

K+ Channel Blocker (Class III)AntiarrhythmicATC C01BD06
CDSCO approvedATC C01BD06
EXCRETION
—
not curated
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
—
not curated
Top interactionssee all 12 →
  • AbarelixSevereDatabaseDDInter
  • AbirateroneSevereDatabaseDDInter
  • AdenosineSevereDatabaseDDInter
  • AlfuzosinSevereDatabaseDDInter

Mechanism

Ibutilide is an IKr blocker that can also activate an inward Na+ current. The action potential–prolonging effect of the drug may arise from either mechanism.

Indications

Immediate conversion of atrial fibrillation to sinus rhythmImmediate conversion of atrial flutter to sinus rhythmPharmacological conversion of atrial flutter (AFl) to sinus rhythmPharmacological conversion of atrial fibrillation (AF) to sinus rhythm (higher efficacy in recent onset AF/AFl and in AFl compared to AF)

Dosing

Adult
1 mg (IV) over 10 min; may repeat once 10 min later.

Pharmacokinetics

Protein binding
Not specified
Metabolism
Extensive first-pass hepatic metabolism

Contraindications

  • Prolonged QT interval

Side effects

Serious
  • Torsades de pointes (up to 6% of patients, requires immediate cardioversion in up to one-third)
  • Induction of Torsades de pointes

Drug interactions

Abarelix
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Abiraterone
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Adenosine
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Alfuzosin
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Alimemazine
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Amiodarone
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Amisulpride
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Amitriptyline
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Amoxapine
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Anagrelide
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Apalutamide
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Apomorphine
Severe
Database

Drug interaction classified as: synergy

Source: DDInter

Related guidelines

Atrial fibrillation
NICE · Cardiology · 2021
Atrial fibrillation
ESC · Cardiology · 2020
Beta-blockers in hypertension
MOHFW · Cardiology · 2024
Hypertrophic cardiomyopathy
ESC · Cardiology · 2026
Primary PCI for acute coronary syndrome
ESC · Cardiology · 2026

Other K+ Channel Blocker (Class III) drugs

dofetilide
0 brands

Ask House about ibutilide

Continue into a citation-backed clinical answer with the drug context already attached.

Open in workspaceAsk House about this drug

Sources: KD Tripathi 7e, Goodman & Gilman 14e·Verified: 2026-05-10 · House clinical team