Safety of Intravenous Olanzapine Administration at a Tertiary Academic Medical Center

Abstract

Background Although approved by the Food and Drug Administration for intramuscular administration only, analyses have described the administration of intravenous push (IVP) olanzapine, particularly for acute agitation. The safety and efficacy of IVP olanzapine has mostly been limited to emergency department patients. Objective To evaluate the safety of IVP olanzapine administration in the inpatient setting. Methods This single-center, retrospective analysis was conducted between July 1, 2018, and December 31, 2019, at Brigham and Women’s Hospital in Boston, Massachusetts. Adult patients who received at least 1 dose of IVP olanzapine were included in the analysis. Safety endpoints analyzed included the following adverse drug events (ADEs): hypotension, bradycardia, cardiac arrhythmias, extrapyramidal adverse effects, and respiratory depressive events. Data on IV site reactions, including phlebitis and infiltration, were also collected. Results A total of 1,247 IVP administrations of olanzapine were identified across 252 patients. Two or more doses were received by 159 patients (63.1%). Most administrations (66%) took place in intensive care units, with 33% administered on general medicine wards. Overall, 104 administrations (8.3%) were associated with at least 1 ADE. Hypotension and bradycardia occurred in 62 (5.2%) and 16 (1.3%) administrations, respectively. Phlebitis occurred with 8 administrations (1.4%). All other adverse events were rare (<1%). Conclusion and Relevance Hypotension, the most commonly noted ADE, occurred more frequently than in previous studies. IVP olanzapine appears to be a safe route of administration in hospitalized patients, including those receiving multiple doses. Further studies are required to evaluate the effect of IV olanzapine on hemodynamics.