olanzapine and Hyperventilation

Olanzapine is increasingly used as a sleep aid in hospitalized patients. Although thought to have less extrapyramidal effects, known side effects include oversedation, arrythmias, and hypotension. We present the unusual case of hyperventilation with respiratory alkalosis after the administration of olanzapine for insomnia in an elderly postoperative patient. This led to a second admission to the intensive care unit with invasive interventions including mechanical ventilation and vasopressor support. Caution must be exercised in prescribing antipsychotics for off-label use, especially in a population whose baseline characteristics can affect the pharmacokinetics of second-generation antipsychotics.

Topics: Aged; Alkalosis, Respiratory; Antipsychotic Agents; Humans; Hyperventilation; Olanzapine; Sleep Initiation and Maintenance Disorders

Although olanzapine therapy has been associated with fewer extrapyramidal side effects than the traditional antipsychotic medications, reported side effects include dystonia, tardive dyskinesia, hypotension, diabetes mellitus, seizures and neuroleptic malignant syndrome. There are no previous published reports of hyperventilation associated with olanzapine therapy, but we present the case of a male patient who developed dyspnea and hyperventilation while taking olanzapine.

Topics: Adult; Antipsychotic Agents; Benzodiazepines; Humans; Hyperventilation; Male; Olanzapine; Pirenzepine; Psychotic Disorders