Difference between revisions of "Torsades de pointes"

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==Background==
 
==Background==
Drugs that inhibit P450
+
*Most commonly occurs in pts w/ prolonged QT due to heart diseaes or meds:
#erythromycin
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**Procainamide
#biaxin
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**Phenothiazine
#ketoconozole
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**TCAs
#itraconozole
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**Qunidine
 
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**Disopyramide
*certain antihistamines like terfandadine or astemizole, inhibit the delayed rectifier potassium channel
 
*terfenadine is completely metabolized in liver. Once metabolized, has no cardiac activity
 
*unmetabolized terfenadine has quinidine- like activity- gives torsades
 
*if P450 enz inhibited by other drug, then will have increase in concentration of unmetabolized terfanadine.
 
  
 
==Treatment==
 
==Treatment==
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==Source ==
 
==Source ==
10/07 DONALDSON (adapted from Tintinalli, Lampe)
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*Tintinalli
  
 
[[Category:Cards]]
 
[[Category:Cards]]

Revision as of 06:13, 26 March 2012

Background

  • Most commonly occurs in pts w/ prolonged QT due to heart diseaes or meds:
    • Procainamide
    • Phenothiazine
    • TCAs
    • Qunidine
    • Disopyramide

Treatment

  1. Magnesium
    1. 1-2gm IV over 1-2 min; then 1-2gm/hr gtt
  2. Overdrive pacing
    1. Goal HR 90-120
  3. Isoproterenol
    1. 2-8 mcg/min

See Also

Source

  • Tintinalli