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Final Program


Psychopharmacology and Toxicology

PO-045

(PO-045) (PO-045) C-L psychiatrists should take protein-binding into consideration when treating neuropsychiatric manifestations of limbic encephalitis in those receiving plasmapheresis


Background: GAD65 and Lgl1 antibody positive autoimmune limbic encephalitis (LE) is a novel disorder with neuropsychiatric manifestations (Boylan, 2000). Treatment often includes immune suppression and/or plasmapheresis (PLEX) (Dalmau, 2018; Pollak, 2020). Treatment of neuropsychiatric manifestations of LE requires consideration of interactions with the co-administered treatments for encephalitis. We present a case with neuropsychiatric manifestations of LE and subsequent psychopharmacological considerations while the patient receives PLEX.



Case: Mrs. X is a 68-year-old female with no significant past medical or psychiatric history who initially presented with paranoia, delusions, memory loss, unsteady gait, fasciobrachial dystonic seizures. She was subsequently diagnosed with LGl1 and GAD65 antibody positive LE and discharged with prednisone following IV solumedrol with good effect. She re-presented two weeks later with manic symptomatology including pressured speech, sleeplessness, increased paranoid and delusional thought content. She received plasmapheresis and adjunctive risperidone to manage behavioral symptoms to which she had a robust response.



Discussion: Plasmapheresis is an effective treatment in LE as it eliminates offending antibodies by removing protein-bound molecules from the bloodstream. Drugs like neuroleptics with high plasma protein binding affinity and low distributing volumes are vulnerable to removal via PLEX therapy (Cheng, 2017). Optimal agent selection is necessary to maximize efficacy and limit pheresis removal. Antipsychotics in general are highly protein bound, ranging from 77% for risperidone to 100% for aripiprazole (Beric, 2017).



Conclusion: We describe a case of patient with LE receiving PLEX treatment presenting with mood and psychotic symptoms that were effectively treated with risperidone therapy. This agent was chosen because it is the least protein-bound antipsychotic and therefore least likely to be impacted by PLEX therapy.



References:



1.Boylan LS. Limbic encephalitis and late-onset psychosis. Am J Psychiatry 2000;157:1343–4.

2.Dalmau J, Graus F. Antibody-Mediated Encephalitis. New England Journal of Medicine 2018;378:840-51.

3.Pollak T et al. Autoimmune psychosis: an international consensus on an approach to the diagnosis and management of psychosis of suspected autoimmune origin. Lancet Psychiatry 2020; 7: 93-108

4.Cheng C, Hendrickson J, Torney C, Sidhu D. Therapeutic Plasma Exchange and Its Impact on Drug Levels. Am J Clin Pathol 2017; 148:190-198

5.Beric J, Jelic R, Nesic D, Stankovic J, Odovic J. Estimation of plasma protein binding of selected antipsychotics using computed molecular properties. Arch Biol Sci 2017; 69 (3):463-469

Learning Objectives:

  • Appreciate that antipsychotic medications are generally highly protein bound and are, thus, vulnerable to removal via plasmapheresis
  • Identify the least and most protein-bound antipsychotic medications
  • Appreciate that using neuroleptic protein-binding profiles may be an important consideration when treating patients with autoimmune encephalitis

    Presenting Author(s)

  • Gregg A. Robbins-Welty, MD, MS

    – Internal Medicine & Psychiatry Resident Physician, Duke University Hospital, Durham, NC, United States

    • Co-Author(s)

  • CU

    Carolyn Usanis, MD

    – Psychiatry Resident, Duke University Hospital, Durham, NC, United States

  • Charles Roark, DO

    – Neurology Resident Physician, Duke University Hospital, Hillsborough, NC, United States

  • Karan Vyas, MD

    – Medical Instructor, Duke University Hospital, Durham, NC, United States