Page 65 - Basic Monitoring in Canine and Feline Emergency Patients

Table 3.6. Anti-arrhythmic drugs commonly used in small animal emergency practice. Medications are grouped by
their Vaughn–Williams classification (Class I-IV), based on cellular mechanism of action.
VetBooks.ir Drug + General indications Dose (dog) Dose (cat)

Class I: Na channel blockers; decrease rate of myocardial depolarization
Lidocaine Emergency treatment of VT IV: initial slow bolus of 2 mg/kg; (Generally avoid)
can repeat up to cumulative IV: initial slow bolus of 0.2 mg/kg
dose of 8 mg/kg (over ≥10 min) CRI: 10–40 μg/kg/min
CRI: 25–80 μg/kg/min
Mexiletine Long-term oral treatment of VT/ PO: 5–8 mg/kg q8h –
VPCs
Procainamide Emergency treatment of VT (if IV: initial slow bolus of 4 mg/kg; IV: initial slow bolus of 1-2 mg/
unresponsive to lidocaine) can repeat up to cumulative kg; can repeat up to
dose of 16 mg/kg cumulative dose of 10 mg/kg
CRI: 10–50 μg/kg/min CRI: 10–20 μg/kg/min
Class II: β-blockers; decrease SNS activation
Atenolol Long-term oral treatment of PO: 0.25–1.0 mg/kg q12h (start PO: 6.25 mg/cat q12h
SNS-mediated VT/VPCs low and up titrate)
or SVT/SVPCs; heart rate
reduction in AF
Esmolol In-hospital treatment of IV: initial bolus of 50–100 μg/kg IV: initial bolus of 50–100 μg/kg
persistent sinus tachycardia over 5 min over 5 min
(usually secondary to toxicity) CRI: 25–50 μg/kg/min CRI: 25–50 μg/kg/min
Class III: K channel blockers; prolong repolarization
+
Sotalol Long-term oral treatment of PO: 2–3 mg/kg q12h PO: 10–20 mg/cat (2–4 mg/kg)
ventricular or supraventricular q12h
arrhythmias
Amiodarone Emergency treatment of PO: loading protocol of 15 mg/ IV (aqueous formulation only):
ventricular tachycardia (if kg q12h for 7 days, then 2.5 mg/kg slow bolus over
unresponsive to lidocaine); 15 mg/kg q24h, then 7.5 mg/ 15 min
long-term oral treatment of kg q24hr
VT/VPCs or SVT/SVPCs IV (aqueous formulation only):
3–5 mg/kg slow IV over 15 min
CRI: 0.05 mg/kg/min
Class IV: Ca channel blockers; decrease SA node rate and AV node conduction
2+
Diltiazem Emergency treatment of SVT; IV: 0.05–0.2 mg/kg over 2–5 IV: 0.05–0.2 mg/kg over 2–5
long-term oral treatment min; can repeat if needed up min; can repeat if needed up
of SVT/SVPCs; heart rate to 0.5 mg/kg to 0.5 mg/kg
reduction in AF CRI: 2–5 μg/kg/min PO (regular formulation):
PO (regular formulation): 7.5 mg/cat q8h
0.5–1.5 mg/kg q8h (start low PO (sustained-release
and up titrate) formulation, Diltiazem ER):
PO (sustained-release 30 mg/cat q12h
formulation, Diltiazem ER): PO (sustained-release
3–6 mg/kg q12h formulation, Cardizem-CD):
10 mg/kg q24h
Positive chronotropes (drugs that increase heart rate)
Atropine Hemodynamically relevant IV/IM/SQ: 0.02–0.04 mg/kg IV/IM/SQ: 0.02–0.04 mg/kg
bradyarrhythmias; response Atropine response test: 0.04 mg/ Atropine response test: 0.04 mg/
test for vagal influence kg SQ kg SQ
Continued

Electrocardiography 57