Atypical antipsychotics associated with increased AKI risk

Use of atypical antipsychotics is associated with increased risk for acute kidney injury (AKI), according to a new study.

Researchers performed a population-based cohort study in Ontario, Canada, from 2003 to 2012 to examine the risk for AKI and other adverse outcomes associated with atypical antipsychotic use versus nonuse. Patients 65 years of age or older who got a new outpatient prescription for an oral atypical antipsychotic drug were matched with patients who didn't get an atypical antipsychotic prescription. The study's primary outcome measure was hospitalization with AKI within 90 days of receiving an atypical antipsychotic prescription. The results appear in the Aug. 19 Annals of Internal Medicine.

The study included a total of 97,777 drug recipients and 97,777 matched nonrecipients. Mean age was 80.7 years. A total of 23.8% of patients lived in long-term care facilities, and 53.8% had been diagnosed with dementia. Risperidone was the most common atypical antipsychotic prescribed (44,707 patients, 45.7%), followed by quetiapine (34,498 patients, 35.3%) and olanzapine (18,572 patients, 19.0%).

Overall, atypical antipsychotic drug use was associated with higher risk for hospitalization with AKI (1.02% vs. 0.62%; relative risk [RR], 1.73 [95% CI, 1.55 to 1.92]; absolute risk increase, 0.41% [95% CI, 0.33% to 0.49%]) compared with nonuse. The association remained consistent in a subpopulation with available information on serum creatinine levels (5.46% vs. 3.34%; RR, 1.70 [95% CI, 1.22 to 2.38]; absolute risk increase, 2.12% [95% CI, 0.80% to 3.43%]). Associations were also seen between atypical antipsychotic drug use and 90-day risk of hospitalization for hypotension (RR, 1.91 [95% CI, 1.60 to 2.28]), acute urinary retention (RR, 1.98 [95% CI, 1.63 to 2.40]), and 90-day risk for all-cause mortality (RR, 2.39 [95% CI, 2.28 to 2.50]).

The authors noted that their study was observational, included only older adults, and involved only 3 atypical antipsychotic drugs, among other limitations. However, they concluded that new use of atypical antipsychotic drugs is common and is associated with increased AKI risk as well as with additional adverse outcomes, such as hypotension and acute urinary retention, that could explain this association.

“The current available evidence calls for a careful reevaluation of prescribing atypical antipsychotic drugs in older adults, especially for the unapproved indication of managing behavioral symptoms of dementia,” the authors wrote. “The drugs should be used only after other approaches have been exhausted; when prescribed, patients must be warned about potential adverse effects.” The authors suggested that proactive clinical monitoring “seems reasonable,” including serum creatinine testing, blood pressure measurement, and a bladder scan for urinary retention, shortly after the drugs are initiated, along with consideration of the drugs as a potential cause in patients who present with AKI and prompt discontinuation if feasible.