Psychoactive medications and risk of delirium in hospitalized cancer patients.
OBJECTIVE
Psychoactive medications are biologically plausible and potentially modifiable risk factors of delirium. To date, however, research findings are inconsistent regarding their association with delirium. The association between exposure to anticholinergics, benzodiazepines, corticosteroids, and opioids and the risk of delirium was studied.


METHODS
A total of 261 hospitalized cancer patients were followed up with repeated assessments by using the Nursing Delirium Screening Scale for up to 4 weeks for incident delirium. Detailed exposure to psychoactive medications was documented daily. Strengths of association with delirium were expressed as hazard ratios (HRs) in univariate and multivariate analyses by using Cox regression models. All medication variables were coded as time-dependent covariates. Whenever possible, exposure was computed by using cumulative daily doses in equivalents; dichotomous cutoffs were determined.


RESULTS
During follow-up (mean, 8.6 days), 43 patients became delirious (16.5%). Delirium was associated with a history of delirium and the presence of hepatic metastases at admission. Analysis of the effect of medications was performed adjusting for these factors. Patients exposed to daily doses of benzodiazepines above 2 mg (HR, 2.04; 95% CI, 1.05 to 3.97), above 15 mg of corticosteroids (HR, 2.67; 95% CI, 1.18 to 6.03), or above 90 mg of opioids (HR, 2.12; 95% CI, 1.09 to 4.13) had increases in the risks for delirium. We did not observe associations between anticholinergics and risk for delirium.


CONCLUSIONS
Exposure to opioids, corticosteroids, and benzodiazepines is independently associated with an increased risk of delirium in hospitalized cancer patients.
Gaudreau
Jean-David
JD
Centre de Recherche en Cancérologie de L'Hôtel-Dieu de Québec, Québec City, Québec, Canada.
Gagnon
Pierre
P
Harel
François
F
Roy
Marc-André
MA
Tremblay
Annie
A
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects / Q000627:therapeutic use; D000704:Analysis of Variance; D015331:Cohort Studies; D016001:Confidence Intervals; D003693:Delirium / Q000139:chemically induced* / Q000453:epidemiology* / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D011336:Probability; D016016:Proportional Hazards Models; D011619:Psychotropic Drugs / Q000009:adverse effects* / Q000627:therapeutic use; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution
D000701:Analgesics, Opioid; D011619:Psychotropic Drugs