Quetiapine-Induced Leukopenia and Neutropenia in an Intensive Care Unit Patient with Delirium

Abstract

Objective:

To report a case of neutropenia in a critically ill trauma patient who was receiving quetiapine for hyperactive delirium.

Case Summary:

A 30-year-old white female was admitted to the neurosurgical intensive care unit following a motor vehicle crash. During her recovery in the intensive care unit, she received quetiapine for hyperactive delirium. The patient was initially started on quetiapine 50 mg/day, which was eventually increased to 100 mg/day. Her white blood cell count and neutrophil count were both noted to be decreasing, eventually reaching a nadir of 2.29 × 10⁹/L and 0.89 × 10⁹/L, respectively. Quetiapine was discontinued and her white blood cell count and neutrophil count returned to normal.

Discussion:

Quetiapine-induced neutropenia has rarely been reported. A MEDLINE search (1991-August 2012) revealed 12 case reports; however, in none of them had neutropenia occurred in critically ill patients. The available case reports reveal a wide variety of doses and durations of treatment with quetiapine-associated neutropenia. A definite mechanism for quetiapine-induced neutropenia is unknown. Quetiapine is structurally related to clozapine, known to cause neutropenia, and it may share a similar mechanism. The Naranjo probability scale revealed possible neutropenia associated with quetiapine.

Conclusions:

With the increased use of quetiapine for hyperactive delirium in intensive care unit patients, health care professionals should be cognizant of the potential for quetiapine to induce neutropenia.