Difference between revisions of "Torsades de pointes"

(Created page with "==Background== Drugs that inhibit P450 - erythromycin - biaxin - ketoconozole - itraconozole == == ==Treatment== 1) Mg (1-2gm over 1-2 minutes; then, 1-2gm/hr gtt) 2)...")
 
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==Background==
 
==Background==
 
 
 
Drugs that inhibit P450
 
Drugs that inhibit P450
 +
#erythromycin
 +
#biaxin
 +
#ketoconozole
 +
#itraconozole
  
- erythromycin
+
*certain antihistamines like terfandadine or astemizole, inhibit the delayed rectifier potassium channel
 
+
*terfenadine is completely metabolized in liver. Once metabolized, has no cardiac activity
- biaxin
+
*unmetabolized terfenadine has quinidine- like activity- gives torsades
 
+
*if P450 enz inhibited by other drug, then will have increase in concentration of unmetabolized terfanadine.
- ketoconozole
 
 
 
- itraconozole
 
 
 
== ==
 
 
 
  
 
==Treatment==
 
==Treatment==
 
+
#Mg (1-2gm over 1-2 minutes; then, 1-2gm/hr gtt)
 
+
#Overdrive pacing (hr = 90-120)
1) Mg (1-2gm over 1-2 minutes; then, 1-2gm/hr gtt)
+
#Isoproterenol (if no pacing, 2-8 mcg/min)
 
+
#lidocaine
2) Overdrive pacing (hr = 90-120)
 
 
 
3) Isoproterenol (if no pacing, 2-8 mcg/min)
 
 
 
4) lidocaine
 
 
 
- 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.
 
 
 
 
 
 
 
  
 
==Source ==
 
==Source ==
 
 
 
10/07 DONALDSON (adapted from Tintinalli, Lampe)
 
10/07 DONALDSON (adapted from Tintinalli, Lampe)
 
 
 
  
 
[[Category:Cards]]
 
[[Category:Cards]]

Revision as of 17:59, 12 March 2011

Background

Drugs that inhibit P450

  1. erythromycin
  2. biaxin
  3. ketoconozole
  4. itraconozole
  • 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

  1. Mg (1-2gm over 1-2 minutes; then, 1-2gm/hr gtt)
  2. Overdrive pacing (hr = 90-120)
  3. Isoproterenol (if no pacing, 2-8 mcg/min)
  4. lidocaine

Source

10/07 DONALDSON (adapted from Tintinalli, Lampe)