Baby Aspirin Effect on Kidney Function

Baby aspirin, also known as low-dose aspirin, is an over-the-counter medicine that is often taken by adults to promote good cardiac health. However, in some instances, baby aspirin can reduce renal efficiency in some adults.

Background

• A study published in The American Journal of Medicine (October 2003) followed 83 advanced-age subjects (56 to 98 years of age) who took aspirin in doses of 100 milligrams daily for cardiac benefit. Renal activity was closely monitored throughout the duration of the study in all patients who participated. Forty control subjects also took part in the study.

Details

• Subjects in the study had urine monitored for uric acid and creatinine (renal function markers) around-the-clock for 2 weeks while baby aspirin was administered and for 3 weeks after the aspirin regimen was discontinued. Blood was also drawn for testing during this time.

Uric Acid

• The amount of uric acid excreted in the urine after 2 weeks on the aspirin regimen decreased significantly in 65 percent of the test subjects, while the uric acid concentrations in those of the control group remained relatively normal. A decrease in uric acid marks a decrease in kidney function.

Creatinine

• A significant decrease in creatinine excretion was present in 72 percent of the test subjects, while the creatinine excretion of the control subjects remained relatively normal. The decrease in creatinine output signifies a decrease in renal function.

Conclusion

• After 3 weeks without receiving low-dose aspirin, most patients had restored kidney function. However, nearly half of the treated subjects had significantly reduced creatinine output beyond the 3 weeks following treatment, compared to only 8 percent of subjects in the control group.

Warning

• Patients of any age who have preexisting compromised function of the kidneys or liver should not begin an aspirin regimen without first consulting with a physician.