[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Antiarrhythmics](https://durgical.com/en/pharmacology/classes/antiarrhythmics/) › Vernakalant # Vernakalant ## Antiarrhythmics? Antiarrhythmics ## High alert? An error with this medicine can cause serious harm: double checks and protocols are used. An intravenous, relatively atrial-selective antiarrhythmic for fast conversion of recent-onset atrial fibrillation. Approved in the EU, not by the US FDA. Updated Nov 12, 2026 ## Quick facts **Group** [Antiarrhythmics](https://durgical.com/en/pharmacology/classes/antiarrhythmics/) **Target** Atrial potassium currents (IK,ACh; Ito through Kv4.3) and hERG, plus rate-dependent sodium-channel block **Used for** Rapid conversion **Key effects** Altered taste · Sneezing · Tingling or numbness **Monitor** Continuous ECG during **ATC** C01BG11 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Clinical What the labels mean - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action Vernakalant potently blocks the acetylcholine-activated potassium current (IK,ACh), which is found mainly in the atria, and also blocks Kv4.3 channels (the transient outward current, Ito) and hERG channels (IKr). Its sodium-channel block is stronger at fast rates and in depolarised tissue, as in atrial fibrillation, and it also inhibits the late sodium current, which may offset the proarrhythmic effect of IKr block. The atrial refractory period lengthens and recent-onset AF often converts, with little change in the QT interval. - Blocks atrial IK,ACh, plus Ito (Kv4.3) and IKr - Rate-dependent Na+ channel block at fast AF rates - Atrial refractory period lengthens - Recent-onset AF often converts to sinus rhythm ## Indications - Rapid conversion of recent-onset atrial fibrillation to sinus rhythm in adults (not effective for atrial flutter) [Atrial fibrillation →](https://durgical.com/en/conditions/atrial-fibrillation/) ## Adverse effects ### Common - Altered taste (dysgeusia) - Sneezing - Tingling or numbness (paraesthesia) ### Serious (rare, important) - Significant hypotension - Bradycardia and AV block - Cardiogenic shock (rare) ## Contraindications - Prolonged QT interval - Low systolic blood pressure - Acute coronary syndrome within the past month - Heart failure NYHA class III–IV; severe aortic stenosis - Second- or third-degree AV block or marked bradycardia without a pacemaker ## Key interactions **Intravenous class I or class III antiarrhythmics** Not given within about four hours before vernakalant. ## What is monitored - Continuous ECG during and after the infusion - Blood pressure and heart rate throughout - Signs of heart failure or shock ## Administration and safety - Intravenous infusion in a monitored setting with resuscitation equipment available. - A second infusion is given only if AF persists and the patient is stable. - The infusion is stopped at once for hypotension, bradycardia or ECG changes. ## Pregnancy and breastfeeding Information on use in pregnancy is limited. ## Nursing care - Before: check blood pressure, QT interval, heart failure status and anticoagulation plan. - During: watch ECG, blood pressure and heart rate continuously. - Warn the patient that taste change, sneezing and tingling are common and brief. - After: monitor until stable; record the rhythm. ## Pharmacokinetics **Absorption** Intravenous infusion only. **Onset and duration** When it works, conversion usually comes within the first hour. ## Memory aid VERNAKALANT hits the Atria: 'A' for Atrial channels, Acute AF, and Avoid in long QT. ## Test yourself Think of the answer, then tap the question to see it. ## Why is vernakalant called atrial-selective? It potently blocks IK,ACh, a potassium current found mainly in the atria, with little effect on the QT interval. ## Which common, harmless adverse effects occur during the infusion? Taste disturbance, sneezing and tingling. ## Which ECG finding rules out vernakalant? A prolonged QT interval. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/vernakalant/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## What the labels mean **High alert** An error with this medicine can cause serious harm: double checks and protocols are used. ## Connections ## Related drugs 4 - [Flecainide](https://durgical.com/en/pharmacology/flecainide/) - [Ibutilide](https://durgical.com/en/pharmacology/ibutilide/) - [Amiodarone](https://durgical.com/en/pharmacology/amiodarone/) - [Propafenone](https://durgical.com/en/pharmacology/propafenone/) ## Related conditions 1 - [Atrial fibrillation](https://durgical.com/en/conditions/atrial-fibrillation/) [← Back to the class: Antiarrhythmics](https://durgical.com/en/pharmacology/classes/antiarrhythmics/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [Vernakalant for the Conversion of Atrial Fibrillation: The New Kid On the Block?](https://pmc.ncbi.nlm.nih.gov/articles/PMC6931979/) (Annals of Noninvasive Electrocardiology, via PubMed Central, 2014); [Efficacy and Safety of Vernakalant for Cardioversion of Atrial Fibrillation and Flutter: A Systematic Review and Meta-Analysis](https://pmc.ncbi.nlm.nih.gov/articles/PMC13666120/) (Journal of Clinical Medicine, via PubMed Central, 2026); [Efficacy and Safety of Intravenous Vernakalant in Rapid Cardioversion of Recent Onset Atrial Fibrillation: A Retrospective Single-Centre Study](https://pmc.ncbi.nlm.nih.gov/articles/PMC11103115/) (Cureus, via PubMed Central, 2024); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=C01BG11) (WHO Collaborating Centre for Drug Statistics Methodology, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. 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