Drug overdose hospitalizations reveal a substantial kidney-injury burden

Kidney injury is a major complication in overdose-related hospital care

Acute kidney injury was documented in 34.5% of drug overdose–involved hospitalizations in the United States between 2016 and 2025, according to a new analysis published in the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report.

The finding shifts attention beyond overdose deaths to the serious complications experienced by people who survive an overdose and require hospital care. Acute kidney injury, often abbreviated as AKI, describes a sudden decline in kidney function. In a hospital setting, it can complicate treatment and may be associated with a more severe inpatient course.

The researchers examined 1,297,847 drug overdose–involved hospitalizations. Their analysis comes as overdose mortality in the United States has recently declined, raising a related question: whether nonfatal but severe complications have changed in the same direction.

The answer is mixed. AKI became more common among overdose-related hospitalizations from 2016 through 2022, then declined from 2022 through 2025. Severe inpatient courses among patients with AKI followed a similar, but slightly later, pattern: an increase through 2023 followed by a decrease through 2025.

Older patients and men had higher documented AKI rates

The study found marked differences by age and sex. AKI was documented in 37.4% of overdose-involved hospitalizations among people aged 65 years and older, compared with 28.2% among those aged 24 years and younger.

Men also had a higher documented rate than women: 38.1% versus 29.4%. These figures describe the share of overdose-involved hospitalizations in each group in which AKI was documented; they do not, on their own, establish why the differences occurred.

The data show that kidney injury is not a marginal issue within overdose care. More than one in three overdose-related hospitalizations in the full analysis had documented AKI. That scale makes renal complications relevant to emergency clinicians, inpatient teams, public-health agencies and providers involved in follow-up care after discharge.

Severe hospital courses were common among those with AKI

Among patients whose overdose-related hospitalization included AKI, 60.9% experienced a severe inpatient course. The study reported a higher percentage among patients aged 24 years and younger, at 68.1%, than among those aged 65 years and older, at 56.1%.

By sex, 61.9% of women with AKI had a severe inpatient course, compared with 60.4% of men. The age pattern is notable alongside the AKI prevalence figures: older patients had a higher documented rate of AKI, while younger patients with AKI had a higher reported percentage of severe inpatient courses.

Those distinctions matter because “overdose-related hospitalization” is not a single uniform clinical event. The new analysis suggests that the burden of kidney injury and the intensity of the subsequent hospital course can vary substantially across patient groups.

The trend improved recently, but the burden remains large

From 2016 to 2022, the percentage of overdose-involved hospitalizations with AKI increased at an annual percentage change of 2.69%. It then declined from 2022 to 2025, with an annual percentage change of minus 5.11%.

For severe inpatient courses among patients with AKI, the percentage increased from 2016 to 2023 at an annual percentage change of 1.82%, before declining from 2023 to 2025 at minus 2.89%.

A decline in the most recent period is encouraging, but it should not obscure the absolute burden described in the report. The analysis still identifies AKI in more than a third of overdose-related hospitalizations and severe inpatient courses in roughly three-fifths of those AKI cases.

Because the source reports trends in documented hospitalizations, its results are best read as a measure of the clinical burden encountered in hospital care. They should not be interpreted as proof that a particular drug, demographic characteristic or treatment pathway directly caused kidney injury in an individual patient.

Prevention and continuity of care are central implications

The authors point to three connected opportunities: preventing drug overdoses, recognizing kidney injury early and improving continuity of kidney care after hospitalization.

• Overdose prevention could reduce the number of patients exposed to the downstream risk of AKI.
• Earlier recognition of kidney injury during hospitalization could help clinicians address a complication associated with severe inpatient courses.
• Follow-up kidney care after discharge may be important for patients whose hospitalization included AKI.

The report adds a practical dimension to overdose response. Public discussion often centers on mortality, but nonfatal overdoses can lead to complex and resource-intensive hospital care. Kidney injury is one of the complications that may shape both the immediate course of treatment and the care required afterward.

For health systems, the data reinforce the value of connecting overdose care with broader medical follow-up. For public-health programs, they support treating overdose prevention as a means of reducing serious nonfatal harm as well as deaths. And for clinicians, the figures underline the need to consider renal injury as a frequent feature of overdose-related admissions rather than an exceptional one.

This article is based on reporting by Medical Xpress. Read the original article.