CORDILOX

What it is

CORDILOX contains verapamil hydrochloride, a calcium ion influx inhibitor. Verapamil exerts its pharmacologic effects by modulating the influx of ionic calcium across the cell membrane of the arterial smooth muscle as well as in conductile and contractile myocardial cells.

Approved indications

— Paroxysmal supraventricular tachycardia. — Atrial fibrillation with rapid ventricular response (except in WPW syndrome). — Atrial flutter with rapid conduction. — Extrasystoles. — Prophylaxis and/or therapy of ectopic arrhythmias (predominantly ventricular extrasystoles). — Acute hypertension. — Acute coronary insufficiency.

Key safety warnings

Verapamil should be given as a slow intravenous injection over at least 2 minutes under continuous ECG and blood pressure monitoring. In atrial fibrillation and simultaneous WPW syndrome there is a risk of inducing ventricular fibrillation. Some patients treated with verapamil responded with life-threatening adverse responses including rapid ventricular rate (in atrial flutter/fibrillation in the presence of an accessory bypass tract), marked hypotension or extreme bradycardia/asystole. Severe hypotension has occasionally occurred following intravenous administration of the drug. On rare occasions this has been followed by a loss of consciousness. If severe hypotension develops, verapamil should be promptly discontinued, and vasoconstrictor substances used. CORDILOX slows conduction across the AV node and rarely may produce second- or third-degree AV block, bradycardia and in extreme cases, asystole. There have been rare cases of severe haemodynamic events – some fatal – after intravenous administration of verapamil to neonates and infants. Intravenous verapamil should not be administered to this group of patients unless it is absolutely necessary and there is no alternative.

Contraindications

CORDILOX is contraindicated in cardiogenic shock (except for arrhythmia induced shock), complicated acute myocardial infarction (bradycardia, hypotension, left ventricular failure), second- and third-degree AV block, sick sinus syndrome (bradycardia-tachycardia syndrome), and manifest heart failure. Patients with atrial flutter or atrial fibrillation and an accessory bypass tract (such as Wolff-Parkinson-White or Lown-Ganong-Levine syndromes) are at risk to develop ventricular tachyarrhythmia including ventricular fibrillation if verapamil is administered. CORDILOX is contraindicated in patients with ventricular tachycardia. Administration of intravenous verapamil to patients with wide-complex ventricular tachycardia (QRS greater than 0.12 seconds) can result in marked haemodynamic deterioration and ventricular fibrillation. CORDILOX injection should not be administered intravenously to patients on beta-blockers (except in an intensive care setting). Concomitant administration of verapamil and ivabradine is contraindicated. CORDILOX is contraindicated in known hypersensitivity to verapamil hydrochloride or any of the excipients.

PBS listing

CORDILOX tablets containing verapamil hydrochloride 180 mg (sustained release) are listed on the PBS with 2 items, restriction types of restricted and unrestricted, at an ex-manufacturer price of A$4.97. Tablets containing verapamil hydrochloride 240 mg (sustained release) are also listed with 2 items, restriction types of unrestricted and restricted, at an ex-manufacturer price of A$6.63.

Regulatory history

CORDILOX SR 240 mg tablet was first listed on the ARTG on 19 August 1991. CORDILOX 180 SR 180 mg tablet was first listed on 4 December 1995.