Vasopressor Requirements in Antipsychotic Overdose: A Poison Center Observational Study.

Purpose/background: The antipsychotic class of medications has a varying degree of peripheral alpha antagonism resulting vasodilation and potentially hypotension. These hemodynamic changes may require treatment with crystalloids and vasopressors. The primary aim of this study was to evaluate the occurrence of hypotension after antipsychotic overdose and characterize vasopressor use.

Methods/procedures: A retrospective cohort study was conducted by chart review of electronic records from 2 regional poison centers from January 1, 2004, to December 31, 2020. Inclusion criteria were single acute antipsychotic exposures evaluated in a health care facility and age >15. Exclusion criteria included missing data, minor or no effect outcomes, and polypharmacy overdose. The primary outcome was hypotension, which was defined as systolic blood pressure <90 mm Hg and/or MAP <65.

Findings/results: There were 4488 single acute antipsychotic overdoses that presented to a healthcare facility after the initial search was conducted. After exclusions, there were 2070 cases with moderate or severe outcomes. The mean age was 42 (SD = 16), and 70% were female. There were 169 cases with hypotension. Of the hypotensive cases, 92% involved atypical antipsychotics, with quetiapine being the most common (n = 128, 76%). Vasopressor therapy was administered in 16/169 cases (9.9%). In the cases where vasopressor use was recorded, norepinephrine was used 12 times, dopamine 3 times, and phenylephrine once. No deaths were reported.

Implications/conclusions: In antipsychotic overdoses that presented to a healthcare facility, hypotension was present in n = 169 (3.8%).

Conclusions: Among patient reports to 2 regional poison centers, we found that hypotension following acute antipsychotic overdose was infrequent and vasopressors are rarely administered.