MGH IV Haloperidol Protocol for Agitation in Delirious Patients

1) Check pre-haloperidol QTc interval

• If QTC > 450 ms, proceed with care
  
• If QTC > 500 ms, consider other options* (see  #6)
  

2) Check potassium and magnesium, and correct abnormalities

• Aim for potassium > 4 mEq/L, magnesium > 2 mEq/L
  

3) Give dose of haloperidol (0.5-10 mg) based on level of agitation, and patient's age and size; start with 1 mg for patients who are elderly; start with 2 mg for non-elderly

• Goal is to have patient calm and awake
  
• Haloperidol precipitates with phenytoin and heparin; flush line before giving haloperidol if thee agents have been used in the IV tubing
  
• Wait 20-30 minutes. If patient remains agitated, double dose.
  
• Continue to double dose q 30 minutes until patient calm
  

4) Follow QTc interval to ensure that QTc is not prolonging

• Obtain EKGs and check QTc prior to the second and third doses of haloperidol administered to assess for lengthening
  
• If QTcs are < 450, can increase interval EKG monitoring to q 24 hrs
  
• If QTc increases by 25% or becomes > 500, consider alternative treatments and monitoring frequency (see # 6)
  

5) Once effective dose has been determined, use that dose for future episodes of agitation

• Depending on likely course of delirium, may schedule haloperidol or give prn (e.g. may divide previous effective dose over next 24 hrs giving q6 hrs)
  
• Consider small dose at night to regulate sleep-wake cycle in all delirious patients
  

6) If QTc is > 500 or is increasing > 25%

• Consider switch to Zyprexa or Abilify as they seem to be least associated with QTc prolongation
  
• If continuing to use antipsychotics, follow QTc closely i.e. prior to each antipsychotic administration, monitor electrolytes closely, particularly K/Mg, and aggressively replete
  
• Primary team should discuss and analyze R/B/A on an individual patient basis
  
• Alternatives include temporizing measures—benzodiazapines, opioids, anticonvulsant mood stabilizers; of note, benzodiazapines and opioids may help to control and contain symptoms of delirium in the short-term but may also be associated with worsening of mental status in delirious patients
  

7) If QTc > 550

• Strongly consider temporizing measures, alternatives to antipsychotics above!
  
• R likely > B at this length of QTc
  

Sources:
Stern, T. Huffman, J. Primary Care Companion J Clin Psych, 2003
The MGH/McLean Psychiatry Residents' Handbook, 2009-2010