Arrhythmias Flashcards
What are the common SEs of anti-arrhythmics?
Pro-arrhythmic -Ventricular arrhythmias -Torsades de Pointes Exacerbate HF Drug interactions: Any other agents that increase QT interval= increased TdP risk
What are the lowest risk agents for Torsades de Pointes?
Amiodarone and dronedarone
What are safe agents for HF?
Dofetilide and amiodarone
When is sotalol safe to use?
Hx of MI
When is sotalol unsafe to use?
HF
What are the class Ia drugs?
Quinidine, procainamide, disopyramide
Quinidine dosing considerations
PO (q6h, q8h,
q12h)
What do class Ia meds treat?
Supraventricular and ventricular arrhythmias
SEs of quinidine
cinchonism
GI disturbances
Hypotension
Thrombocytopenia
Monitoring for quinidine
CBC
BMP
LFTs
BBW for quinidine
Increased mortality
Dosing considerations for procainamide
IV bolus followed by infusion
Dose adjustment for quinidine
Hepatic
Dose adjustment for procainamide
Hepatic
Renal
SEs of procainamide
Hypotension
Drug induced lupus (BW)
Agranulocytosis (BW)
Dosing considerations for disopyramide
PO (IR-q6h, SR BID)
Dose adjustment for disopyramide
Hepatic, renal
SEs of disopyramide
Anticholinergic sx (xerostomia), nausea, anorexia, constipation
Monitoring for disopyramide
Urinary retention
Anticholinergic sx
BP
What are the class Ib meds?
Lidocaine
Mexiletine
Dosing considerations lidocaine
IV push: continuous infusion
Dose adjustment in lidocaine
Liver dz
HF
Indication for lidocaine
Vfib
Vtach
SEs of lidocaine
Neurotoxicity: psychosis, seizures, paresthesia, confusion
Monitoring for lidocaine
Drug levels >24h
EKG
Dosing considerations for mexiletine
200-300 mg PO q8h
Dose adjustment for mexiletine
Hepatic dysfunction (esp if HF as well)
Indication for mexiletine
Ventricular arrhythmias
SEs of mexiletine
Dizziness Sedation Paresthesia Seizure Confusion N/V
Monitoring for mexiletine
LFTs
ECG
Considerations for mexiletine
Hepatotoxicity (BW)
What are class Ic meds?
Flecainide
Propafenone
Dosing considerations flecainide
50-200 mg q12h
Dose adjustment for flecainide
Hepatic and renal
Indications for flecainide
Atrial and ventricular arrhythmias
SEs of flecainide
Dizziness
Blurred vision
HF exacerbation
Dyspnea
Monitoring for flecainide
Measure trough levels
Renal/hepatic impairment
Pediatric: use with amiodarone
Considerations for flecainide
Pill in the pocket: 300 mg PO x 1
Dosing considerations propafenone
150-300 mg q8h
225-425 mg q12h
Dosing adjustments for propafenone
Hepatic
Indication for propafenone
Atrial arrhythmias
SEs of propafenone
Dizziness Blurred vision Bronchospasm Taste disturbance HF exacerbation
Monitoring for propafenone
Pulse (at beginning of therapy)
Considerations for propafenone
Pill in the pocket: 450 mg PO x 1
What are the class III meds?
Amiodarone Dronedarone Sotalol Ibutilide Dofetilide
Indication for amiodarone
Ventricular and atrial arrhythmias
Warfarin + amiodarone
Decrease warfarin dose by 30% on a pt already on warfarin
Digoxin + amiodarone
Reduce digoxin dose empircally by 50%
SEs of amiodarone
Severe bradycardia/heart block Hyper and hypothyroidism Peripheral neuropathy GI discomfort Photosensitivity Blue-gray skin discoloration Fluminant hepatitis Pulmonary fibrosis Optic neuropathy/neuritis (blindness) Corneal microdeposits
Monitoring and management of severe bradycardia/heart block in amiodarone
Monitor: ECG baseline and every 3-6 mos
Management: Lower dose or d/c if severe
Monitoring and management of hyper and hypothyroidism in amiodarone
Monitor: TSH/T4 baseline and every 6 mos
Manage: Medication therapy- levothyroxine/methimazole
Monitoring and management of peripheral neuropathy in amiodarone
Monitor: PE at each office visit
Manage: Lower dose or d/c if severe
Monitoring and management of photosensitivity in amiodarone
Monitor: PE at each office visit
Manage: Lower dose or d/c if severe
Monitoring and management of blue-gray skin discoloration in amiodarone
Monitor: PE at each office visit
Manage: Lower dose or d/c if severe
Monitoring and management of fulminant hepatitis in amiodarone
Monitor: LFTs baseline and every 6 mos
Manage: Lower dose or d/c (if LFTs>3x ULN)
Monitoring and management of pulmonary fibrosis in amiodarone
Monitor: CXR baseline and every 12 mos
PFTs (if sx)
Manage: D/c amiodarone immed.
Start cortiocosteroid
Monitoring and management of optic neuropathy/neuritis in amiodarone
Monitor: Ophthalmologic exam baseline and if sx
Manage: D/c amiodarone immediately
Monitoring for corneal microdeposits in amiodarone
Slit-lamp exam
When should you avoid dronedarone?
With potent CYP3A4 inhibitors/inducers
Dose of dronedarone
400 mg PO BID with food
MOA of dronedarone
PGP inhibitor
Increased digoxin levels
Reduce digoxin by 50%
Pros of dronedarone
Shorter half life (no LD, quicker recovery from adverse effects)
No significant pulmonary, hepatic, or thyroid toxicity
Fewer DIs
Cons of dronedarone
BBW in decompensated HF Similar to amiodarone with bradycardia, QT prolongation Mild increase in creatinine Less effective than amiodarone Cost
Dosing of dofetilide
CrCL >60 mL/min: 500 mcg PO BID
Monitoring for dofetilide
Should be initiated in the hospital bc risk of QT prolongation causing TdP is very high
ECG after each dose and dose reduction if QT prolonged >15%
Monitor K with loop diuretics
Do not use in noncompliant pts
SEs of dofetilide
HA
Dizziness
TdP
Sotalol dosing
80-160 mg PO BID
CrCl<50 mL/min: increase frequency to once daily
Monitoring for sotalol
Should be initiated in the hospital bc risk of QT prolongation causing TdP is very high
Monitor telemetry for ~5 doses
Adverse effects of sotalol
Bradycardia AV block TdP Fatigue Bronchospasm
Ibutilide dosing
1 mg IV x 1 dose, may repeat one time if unsuccessful
May administer Mg prophylactically to minimize QT prolongation
Indication for ibutilide
Pharmacological cardioversion (direct current cardioversion still preferred)
Adverse effects of ibutilide
HA
TdP
Hypotension
How to treat sinus brady in hemodynamically unstable pts
Atropine 0.5 mg IV q3-5 mins (max total dose= 3 mg)
How to treat sinus brady in refractory pts
Dopamine IV infusion
Epinephrine IV infusion
Isoproterenol IV infusion
Tx of AV nodal block
Same as sinus brady
No isoproterenol
