About one in three people hospitalized for an opioid, cocaine or stimulant overdose in the United States also had acute kidney injury, according to a Centers for Disease Control and Prevention report. The study found the injury in 448,136 of 1,297,847 overdose hospital stays from 2016 through 2025, or 34.5%.
The report appeared in the agency’s Morbidity and Mortality Weekly Report on Oct. 22. Sola Han, Hui Xie and Meda Pavkov of the CDC’s Division of Diabetes Translation wrote it with Fang Xu and Gery Guy of the Division of Overdose Prevention. The authors reported no conflicts of interest.
How the CDC Counted Overdose Hospitalizations
The authors used the Premier Healthcare Database, an all-payer hospital database that covers about 1,400 hospitals and health systems, or roughly 25% of U.S. inpatient admissions each year. They counted stays in which an opioid, cocaine or psychostimulant poisoning was present on admission, whatever the intent. They left out patients with end-stage kidney disease or those on chronic dialysis.
Acute kidney injury was defined by diagnosis codes, not by lab values. The authors say that method likely undercounts true cases. They counted hospitalizations, not patients, so one person who was admitted twice appears twice. The report calls a “severe inpatient course” any AKI case that involved acute dialysis, respiratory compromise, shock or low blood pressure, or death in the hospital. Of the 448,136 AKI cases, 273,093 met that definition, which is 60.9%.
What the Report Found on Kidney Injury Over Time
The share of overdose hospitalizations with kidney injury rose from 2016 to 2022, at an annual rate of 2.69%, and then fell by 5.11% a year from 2022 to 2025, the authors report. The decline after 2022 was statistically significant in every subgroup they examined. The share with a severe course among AKI cases rose through 2023 and then fell by 2.89% a year through 2025. Comparing only the endpoints hides that swing. The crude share was 31.6% in 2016 and 31.9% in 2025. The 10-year share of 34.5% is higher than both, which fits a peak in between.
The report’s table prints only the two endpoint years, so the middle years are not available in the text. The number of overdose hospitalizations also fell, from 139,603 in 2016 to 108,299 in 2025. That is 31,304 fewer stays, a 22% decline, a calculation from the report’s table. Multiplying each year’s total by its AKI share gives roughly 44,100 AKI stays in 2016 and 34,500 in 2025, a drop of about 9,600. The same method puts severe-course AKI stays at about 25,200 in 2016 and 21,100 in 2025.
These are calculations that apply the crude percentages to the table totals, and they are approximations. In 2025 the figures work out to about 297 overdose hospitalizations a day, of which about 95 involved kidney injury. The authors list one reason the hospital counts may have changed. Naloxone, the medicine that reverses opioid overdoses, became more widely available starting in 2019, and that may have altered which opioid overdoses ended in a hospital stay.
Age and Sex Differences in Overdose AKI
Kidney injury became more common with age. It appeared in 28.2% of stays for patients 24 and younger, 33.8% for ages 25 to 44, 35.4% for ages 45 to 64 and 37.4% for patients 65 and older. Severe courses moved the other way. Among AKI cases, 68.1% of patients 24 and younger had a severe course, compared with 62.5% at ages 25 to 44, 61.0% at 45 to 64 and 56.1% at 65 and older.
The authors write that some drug overdose-related AKI might be preventable because the exposure is identifiable. They single out the youngest group as a concern, since a young person who loses kidney function has more years ahead in which chronic kidney disease or kidney failure could develop. They add that illicit drug use is tied to more severe injury in younger people, and they say age differences in the drugs involved may partly explain the pattern.
Sex differences ran in opposite directions. Kidney injury appeared in 38.1% of male overdose stays and 29.4% of female stays. Among AKI cases, 61.9% of women had a severe course, against 60.4% of men. The report says the evidence on sex-specific patterns of unstable blood pressure in this group is limited.
A calculation from the report’s own percentages shows how the two measures combine. Multiplying the AKI share by the severe-course share gives about 23% of all male overdose stays with severe-course AKI, against about 18% for female stays. For patients 24 and younger the product is about 19%, and for patients 65 and older it is about 21%. The product is a rough estimate because it multiplies two reported percentages that the authors modeled separately. It suggests that the age groups end up closer together than either measure alone implies, while men remain more likely overall to have a severe case.
Why Kidney Injury Matters After Discharge
The report says AKI occurs in approximately 20% of hospitalized adults, and that after an overdose it can come from muscle breakdown, reduced blood flow to the kidneys or direct kidney toxicity from a substance. The authors describe AKI as both a short-term complication and a marker of later chronic kidney disease.
The follow-up numbers are low. The report cites Medicare data showing that 13.6% of beneficiaries had their kidney function checked after an AKI episode in 2023. The national target in Healthy People 2030 is 16.4%, so the figure sits 2.8 percentage points short, a calculation from the two numbers. Guidelines from the KDIGO kidney group recommend a kidney function assessment within three months of AKI, according to the report.
The stakes are visible in a separate CDC estimate. The agency says about 14% of U.S. adults, or 37 million people, are estimated to have chronic kidney disease, and about 87% of adults with the disease do not know they have it. The CDC notes that those estimates rest on a single test and may be too high.
What the Report Cannot Show
The authors list six limits. Hospitals in the Premier database may differ from those outside it in size, location and overdose rates. The study did not track repeat admissions. Diagnosis codes probably undercount AKI. The authors did not adjust for every related condition, and they did not measure intensive care use or length of stay.
The drug categories also come from codes. The report cannot separate drug combinations, adulterants, doses, the route of use or the timing, and it cannot account for other drugs that harm the kidney. The results are not broken out by opioid, cocaine or psychostimulant. Drug type was used only to adjust the models.
The authors recommend that clinicians watch for AKI in overdose patients, especially younger patients and women with severe complications. They also recommend linking patients to kidney follow-up and addiction treatment after discharge, and they cite naloxone distribution and substance use treatment as ways to prevent overdoses.
