(141) Therapeutic Challenges Following Antipsychotic-induced Angioedema: A Case Report and Review of Literature

Abstract:

Background: Angioedema is a potentially lethal inflammatory drug reaction involving subcutaneous or submucosal swelling (Salih and Thomas, 2006). While the classic pharmacological culprits for angioedema are antihypertensives, case reports have shown an association of angioedema with multiple antipsychotics (Williams, 2019). We present the case of a patient with angioedema which was initially attributed to clozapine and recurred with risperidone; we were able to successfully treat her with fluphenazine.



Case: Ms. R, a 55-year-old with hypothyroidism, hypertension, and schizoaffective disorder complicated by pseudocyesis (prescribed clozapine 150 mg nightly) presented with dyspnea of several hours' duration. She was diagnosed with angioedema initially attributed to carvedilol and required intubation. She previously had developed angioedema when lisinopril and clozapine were started together during a recent psychiatric admission.



Clozapine was discontinued by the psychiatry team, and after resolution of angioedema, risperidone 1 mg twice daily (previously tolerated by patient) was started for psychosis. Within hours of retrial, she developed recurrence of angioedema, requiring epinephrine and dexamethasone. After a 5–7-day washout period in coordination with the Allergy and Immunology service, loxapine was considered given its success in a similar case (Williams, 2019). Fluphenazine was started at 2.5 mg daily in the intensive care unit (ICU) instead, as loxapine could not be diluted for a graded challenge; notably, no studies report angioedema with fluphenazine. She tolerated this, was discharged on a final dose of 5 mg nightly four days later, and has continued to do well.



Discussion: While angioedema usually occurs within the first week of initiating new medications, attacks can occur weeks or months later (Salih and Thomas, 2006). Ms. R had prior experience with risperidone but developed angioedema during this trial. Few studies provide guidance regarding cross-reactivities among classes of antipsychotics leaving the consultation psychiatrist to rely on clinical judgement. Case discussion will include an overview of common antipsychotic medications reported to cause angioedema and practical guidance for the consultation liaison psychiatrist regarding acute recommendations for the inpatient medical setting while providing a detailed literature review. Our case features the novel use of fluphenazine in a patient demonstrating possible cross-reactivity between clozapine and risperidone.



Implications: Antipsychotics should be considered as a potential cause of angioedema, with the possibility of cross-reactivity. Fluphenazine should be considered when patients have previously developed angioedema on other antipsychotics.



References:

Salih, I. and Thomas, S. (2006), Causes and management of drug-induced angioedema. Prescriber, 17: 14-18.

Williams G. D. (2019). Cross-reaction of angioedema with clozapine, olanzapine, and quetiapine: A case report. The mental health clinician, 9(5), 315–317.