Drug Induced Cardiac Injury Flashcards
3 Mechanisms of Drug Induced Cardiac Injury
QTc Prolongation (Torsades de Pointes)
HF
Myocardial Ischemia
Normal QTc
men < 470
women < 480
QTc prolongation
> /= 500
/= 60 increase from baseline
Meds that cause QTc Prolongation ABC’s
A:
Antiarrhythmics:
- amiodarone
- sotalol
- dofetilide
Meds that cause QTc Prolongation ABC’s
B:
Antibiotics:
- Fluoroquinolones (-floxacin)
- macrolides (erythromycin, clarithromycin, azithromycin, etc.)
Meds that cause QTc Prolongation ABC’s
C:
Antipsychotics:
- chlorpromazine
- fluphenazine
- perphenazine
- prochlorperazine
- haloperidol
Meds that cause QTc Prolongation ABC’s
D:
Antidepressants:
- Citalopram
- TCAs (Amitriptyline, Doxepin, Imipramine, Nortriptyline, etc.)
Meds that cause QTc Prolongation ABC’s
E:
Antiemetics:
- ondansetron
Meds that cause QTc Prolongation ABC’s
F:
Antifungals:
- azole antifungals
TdP Prevention
- avoid agents in pats with baseline QTc > 450
- reduce/DC if pats QTc increases > 60 from baseline
- DC if QTc > 500
- Maintain K>4 and Mg>2
TdP Treatment
- DC offending agent
- Mg push or infusion (push if no pulse)
- Transcutaneous pacing
- Isoproterenol infusion ($$$, can use epinephrine or atropine instead)
- if hemodynamically unstable -> cardioversion or defibrillation
3 main causes of drug induced HF
- Sodium and volume retention
- Direct cardiotoxicity -> cardiomyopathy
- Negative inotropy
Agents that cause sodium and volume retention (HF)
- NSAIDs
- Steroids
- Thiazolidinediones (TZDs)
Agents that cause cardiomyopathy
- Chemotherapeutic agents (anthracyclines, alkylating agents)
- Trastuzumab
- Alcohol
Agents that cause Negative Inotropy
NDCCBs (diltiazem, verapami)
Beta blockers (-olol)