≪ View Page

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

wikitox:2.1.11.9.3_antipsychotics [2018/09/01 09:00] – created - external edit 127.0.0.1wikitox:2.1.11.9.3_antipsychotics [2025/04/13 05:00] (current) – ↷ Links adapted because of a move operation 81.8.69.158
Line 147: Line 147:
 **Arrhythmias** \\ It is often very difficult to distinguish whether the patient is having a supraventricular arrhythmia with aberrant conduction or primary ventricular tachycardia. Most arrhythmias, especially if they are associated with low output are treated in a standard cardiac arrest protocol manner. The main difference is the expected benefit from early and large doses of NaHCO<sub>3</sub>. **Arrhythmias** \\ It is often very difficult to distinguish whether the patient is having a supraventricular arrhythmia with aberrant conduction or primary ventricular tachycardia. Most arrhythmias, especially if they are associated with low output are treated in a standard cardiac arrest protocol manner. The main difference is the expected benefit from early and large doses of NaHCO<sub>3</sub>.
  
-//Alkalinisation// \\ Treatment with plasma [[:wikitox:alkalinisation|]] to a pH of 7.5 using sodium bicarbonate (to alter both pH and sodium) or hyperventilation may be effective for neuroleptic induced arrhythmias (extrapolating from TCAs). Initial treatment is normally with sufficient IV NaHCO<sub>3</sub>  to produce a pH of 7.5 to 7.55. Following the rapid correction of pH to 7.5 by IV NaHCO<sub>3</sub>, the patient is usually maintained at this pH by mild hyperventilation. Alkalosis may affect the partitioning of neuroleptics between the cell membrane and the Na<sup>+</sup>   channel binding site and thus decrease Na<sup>+</sup>   channel blockade.+//Alkalinisation// \\ Treatment with plasma [[:concept_serum_alkalinization]] to a pH of 7.5 using sodium bicarbonate (to alter both pH and sodium) or hyperventilation may be effective for neuroleptic induced arrhythmias (extrapolating from TCAs). Initial treatment is normally with sufficient IV NaHCO<sub>3</sub>  to produce a pH of 7.5 to 7.55. Following the rapid correction of pH to 7.5 by IV NaHCO<sub>3</sub>, the patient is usually maintained at this pH by mild hyperventilation. Alkalosis may affect the partitioning of neuroleptics between the cell membrane and the Na<sup>+</sup>   channel binding site and thus decrease Na<sup>+</sup>   channel blockade.
  
 //Further drug treatment of arrhythmias// \\ All other treatments are of questionable efficacy and safety and therefore controversial. All class 1a antiarrhythmic drugs are contraindicated and [[:wikitox:lignocaine|]] and [[:wikitox:2.1.11.2.1_phenytoin|phenytoin]] (class 1b drugs), while they may be used, may exacerbate Na+ channel blockade and potentially exacerbate arrhythmias (e.g. convert VT into asystole). [[:wikitox:magnesium_treatment|Magnesium]] is normally the drug of choice for treating torsade de pointes and is used for refractory arrhythmias in other settings. However, its calcium channel blocking activity may aggravate the hypotension and heart block that can also complicate neuroleptic poisoning. Second or third degree heart block should be treated with bicarbonate and isoprenaline followed by a pacemaker. //Further drug treatment of arrhythmias// \\ All other treatments are of questionable efficacy and safety and therefore controversial. All class 1a antiarrhythmic drugs are contraindicated and [[:wikitox:lignocaine|]] and [[:wikitox:2.1.11.2.1_phenytoin|phenytoin]] (class 1b drugs), while they may be used, may exacerbate Na+ channel blockade and potentially exacerbate arrhythmias (e.g. convert VT into asystole). [[:wikitox:magnesium_treatment|Magnesium]] is normally the drug of choice for treating torsade de pointes and is used for refractory arrhythmias in other settings. However, its calcium channel blocking activity may aggravate the hypotension and heart block that can also complicate neuroleptic poisoning. Second or third degree heart block should be treated with bicarbonate and isoprenaline followed by a pacemaker.