Vernakalant

Danger

H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

P260, P264, P280, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P321, P363, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 37 reports by companies from 1 notifications to the ECHA C&L Inventory.

C01BG11

C - Cardiovascular system

QC - Cardiovascular system

Vernakalant blocks currents in all phases of atrial action potential including atria-specific potassium currents (the ultra-rapid delayed rectifier and the acetylcholine dependent potassium currents) and prolongs the refractory period. It dose-dependently prolongs atrial refractoriness, prolongs AV nodal conduction and refractoriness, and slightly prolongs QRS duration without significantly affecting ventricular refractory period. Vernakalant has a high affinity to ion channels specifically involved in repolarization of atrial tissue and is thought to have a low proarrhythmic potential.

Vernakalant blocks atrial voltage-gated sodium channels in a dose and frequency-dependent manner and inhibits late sodium current (INa)which confers its effect on intra-atrial conduction. This current blockade enhance and onset of drug action accelerates in higher heart rate as the affinity of vernakalant for INa also increases. Its binding offset is quick once the heart rate slows. It also blocks Kv 1.5 channel and its early activating potassium channels (IKur) and inhibits acetylcholine-activated potassium channels (IKAch), which are specific to the atrium and cause prolongation of atrial refractoriness. Vernakalant also blocks Kv4.3 channel and its cardiac transient outward potassium current (Ito), which is involved more with atrial than ventricular refractoriness. Vernakalant minimally blocks hERG channels and its rapidly activating/delayed rectifying potassium current (IKr) which accounts for mild QT prolongation. QRS widening due to INa blockade also contributes to QT prolongation.