NIH Clinical Center
Dept. of Lab Medicine | Dept. of Transfusion Medicine | Anatomic Pathology Test Guide > Lab Test
 Lab Test
 Test Description
Panel Name:
Test Name:
Panel Tests:Haloperidol, Reduced Haloperidol
LIS Test Code:HALO2
Department:Laboratory Medicine
Lab Area:Chemistry
TAT:2-5 days
 Specimen Collection


Container:Red (Plastic)

Micro. Container:

Collection Instructions:

Delivery Instructions:Send specimen to 2C324 or Tube Station 321
Specimen Type: Blood
Frequency / Restrictions:
 Expected Values/Results

Ranges and Interpretation:

Haloperidol  ng/mL
Performed at Mayo Medical Laboratories, Rochester MN
Effective 09Aug11 – present:


Organisms Reported:

Alert Limits:

 Additional Test Information


Haloperidol (Haldol) is a member of the butyrophenone class of neuroleptic drugs used to treat psychotic disorders (eg, schizophrenia). It is also used to control the tics and verbal utterances associated with Tourette's syndrome and in the management of intensely hyperexcitable children who fail to respond to other treatment modalities.

The daily recommended oral dose for patients with moderate symptoms is 0.5 to 2.0 mg; for patients with severe symptoms, 3 to 5 mg may be used. However, some patients will respond only at significantly higher doses.

Haloperidol is metabolized in the liver to reduced haloperidol, its major metabolite.(1,2)

Use of haloperidol is associated with significant toxic side effects, the most serious of which include tardive dyskinesia which can be irreversible, extrapyramidal reactions with Parkinson-like symptoms, and neuroleptic malignant syndrome. Less serious side effects can include hypotension, anticholinergic effects (blurred vision, dry mouth, constipation, urinary retention), and sedation. The risk of developing serious, irreversible side effects seems to increase with increasing cumulative doses over time.(1,3)

Clinical Reference:

1. Lawson GM: Monitoring of serum haloperidol. Mayo Clin Proc 1994;69:189-190

2. Ereshefsky L, Davis CM, Harrington CA, et al: Haloperidol and reduced haloperidol plasma levels in selected schizophrenic patients. J Clin Psychopharmacol 1984;4:138-142

3. Volavka J, Cooper TB: Review of haloperidol blood level and clinical response: looking through the window. J Clin Psycho-pharmacol 1987;7:25-30

4. Moulin MA, Davy JP, Debruyne JC, et al: Serum level monitoring and therapeutic effect of haloperidol in schizophrenic patients. Psychopharmacology 76:346-350, 1982

5. Van Putten T, Marder SR, Mintz J, Polant RE: Haloperidol plasma levels and clinical response: a therapeutic window relationship. Am J Psychiatry 1992;149:500-505

6. Shostak M, Perel JM, Stiller RL, et al: Plasma haloperidol and clinical response: a role for reduced haloperidol in antipsychotic activity? J Clin Psychopharmacol 1987;7:394-400


Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)


Potentially interfering drugs include hydroxyzine (interferes with haloperidol), tiagabine (interferes with reduced haloperidol), and quetiapine (interferes with internal standard resulting in artificially low haloperidol).

Archived Ranges:Historical Reference Ranges


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