Pharmacological interventions in hypoactive delirium: mapping the evidence through a scoping review

Background Hypoactive delirium is the most often overlooked delirium subtype and is associated with increased mortality, prolonged hospitalization, and functional decline. Despite its clinical relevance, evidence guiding pharmacologic management remains limited and highly variable. This scoping review mapped available research on pharmacological interventions for hypoactive delirium in hospitalized adults. Methods Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Joanna Briggs Institute (JBI) guidelines, a comprehensive search of major biomedical and psychological databases identified studies published between January 2015 and October 2025. Eligible studies included adults diagnosed with hypoactive delirium using validated instruments or Diagnostic and Statistical Manual of Mental Disorders criteria. Randomized trials, observational studies, and systematic reviews were included. Data were synthesized descriptively. Results Ten studies met inclusion criteria (three randomized clinical trials, two retrospective cohort studies, and five systematic reviews). All were conducted in high-income countries. Antipsychotic findings were inconsistent: quetiapine showed potential symptom reduction in one cohort study, and olanzapine demonstrated better tolerability than haloperidol in cancer patients, but large trials found no reduction in delirium duration or mortality with haloperidol or ziprasidone. Limited preliminary evidence suggested possible benefit from aripiprazole, methylphenidate, dexmedetomidine, and flumazenil, though samples were small and methods heterogeneous. Conclusions Current evidence does not support routine pharmacologic treatment for hypoactive delirium. The literature remains fragmented, with significant gaps requiring well-designed, subtype-specific clinical trials to define effective and safe therapeutic strategies.