Veterinary Cardiorespiratory Centre

Veterinary Cardiorespiratory Centre

INFORMATION SHEET

Mexiletine (Mexitil, Boehringer)

withdrawal from the market

We have been in contact with Boehringer and confirmed that they have indeed decided to no longer manufacturer mexiletine for “commercial reasons”. There is no alternative manufacturer of mexilitine and no generic available in the UK.

What are the alternatives to mexiteline?

Depends upon why your patient is on mexilitine….

for SVTs

We have used mexiletine very successfully for suppression of re-entrant supraventricular tachycardias (SVT) – thus a lot of our patient are on it for this reason. At this time we have no experience for what alternative drugs will match the anti-arrhythmic properties of mexiletine! However possible drugs to consider are: diltiazem, sotalol and propafenone.

for VPCs

For dogs in which mexiletine was used for control of ventricular premature complexes (VPCs), then our initial plan is to use sotalol. Additionally there is good veterinary experience for the use of this drug for control of VPCs, particularly in Boxers.

Drug dosages and indications

Note: ALL these drugs should be used with caution in dogs with myocardial failure, ie. start at a low dose.

Diltiazem

Vet licensed: Hypercard 10mg

Human licensed: Dilcardia SR 60mg, 90mg tabs, Dilzem SR 60mg, 90mg tabs + a number of others

Arrhythmia indications : For slowing conduction through the AV and thus the ventricular response rate. So can be used to treat atrial automatic tachycardia, atrial flutter and fibrillation. Has no effect on bypass tracts (common with SVT) – and our experience in this setting has been disappointing.

Dose: 1 – 2 (to 3) mg/kg tid

Sotalol

Vet licensed: None

Human licensed: Beta-Cardone 40mg, 80mg + generic.

Arrhythmia indications :

Ventricular arrhythmias – there is good experience for use in Boxers and thus this will be a good drug of choice for this reason.

Supraventricular tachycardia (SVT) – No experience. In man is reported to have effects on re-entrant SVT – thus this might be worth trying.

Dose: 1 – 3 mg/kg bid

Propafenone

Vet licensed: None

Human licensed: Arythmol 150mg, 300mg

Arrhythmia indications :

Ventricular arrhythmias – Indicated in man for the treatment of ventricular arrhythmias. But our initial preference will be for sotalol in dogs.

Supraventricular tachycardia (SVT) – In man is reported to have effects on re-entrant SVT, as well as atrial flutter, and may be slightly more effective than sotalol.

Dose: 3 – 4 (to 5) mg/kg tid

As we gain experience with the use of these drugs, we will be able to provide more feedback.

Additionally please share your experiences – good and bad – with us to add to current knowledge.

This is a small, but really a very important request. Please take the time to give us a call, fax or email.

T: 01926 863445 F: 01926 863446 E: