Receptors

hERG

Rapid delayed rectifier potassium channel (KCNH2 / hERG)

Also known as: hERG, KCNH2, Kv11.1, canal_k

What it is

Cardiac potassium channel (KCNH2) that controls ventricular repolarisation (QT interval on ECG). Drug-induced hERG inhibition can prolong QT and trigger serious ventricular arrhythmias (torsades de pointes).

Role in interactions

Many drugs from diverse classes (antipsychotics, macrolide antibiotics, antiarrhythmics, antidepressants) inhibit hERG and prolong QT; co-administration of multiple hERG inhibitors increases risk additively.

Common substrates

Substrates: Kv11.1 potassium channels (therapeutic target of class III antiarrhythmics such as sotalol).

Inhibitors

hERG inhibitors (cause QT prolongation): sotalol, amiodarone, haloperidol, pimozide, erythromycin, ciprofloxacin, fluconazole, citalopram, escitalopram, methadone, clozapine, olanzapine, quetiapine.

Inducers

Inducers: not applicable.

Clinical notes

QT prolongation is a class effect of many psychotropics and antibiotics; avoid multiple hERG inhibitors simultaneously, especially in at-risk patients (hypokalaemia, cardiac disease, baseline QT prolongation).

Source

DailyMed/FDA (NIH/NLM) — approved labels (sotalol, haloperidol, erythromycin, citalopram); EMC-UK (MHRA) — SmPC