Kidney Disease Outcomes Worsened By Topical Carbonic Anhydrase Inhibitors

Kidney disease patients may have worse renal outcomes if they use topical carbonic anhydrase inhibitors (CAIs) to treat primary open-angle glaucoma (POAG), according to research published in American Journal of Ophthalmology. The drug class’s use may carry higher risks of long-term dialysis and metabolic acidosis in patients with predialysis advanced chronic kidney disease (CKD), researchers report.

Because POAG and kidney disease have similar pathogenic mechanisms and are commonly comorbid, the study primarily sought to evaluate the relationship between CAI use and renal outcomes and mortality rates in patients with both POAG and CKD. Researchers evaluated population data from 2423 Taiwanese patients with CKD who were diagnosed with glaucoma between January 2000 and June 2009. Patients were grouped into CAI users (n=257) and CAI non-users (n=2166). CAI users tended to be younger, men, and have a lower incidence of diabetes mellitus. CAI users also were more likely to use medications such as beta blockers or loop diuretics compared with CAI non-users. 

CAI users were somewhat more likely to receive long-term dialysis compared with CAI non-users (incidence 1216.85 vs 764.17 events per 100 patient years; HR, 1.51; 95% CI, 1.30-1.75). CAI users were also reported more hospital admissions due to metabolic acidosis (incidence 21.54 vs 11.87 events per 100 patient-years; HR, 1.71; 95% CI, 0.98-2.97). These trends persisted after adjusting for baseline covariates. The risks of all-cause mortality, death before long-term dialysis, major adverse cardiovascular events, and admission due to heart failure were comparable between the 2 groups. 

Together, these data suggest that patients with advanced kidney disease may be at risk of progression following topical CAI use. For clinical practice, the study authors recommend, “monitoring renal function and serum sodium bicarbonate levels periodically after prescribing topical CAIs in advanced CKD patients. Changing of CAIs to other classes of topical glaucoma medication, if applicable based on the patients’ clinical status and their severity, might correct CAI-associated complications in advanced CKD patients. ”

The researchers add that ophthalmologists, nephrologists, and all physicians managing patients with chronic kidney disease must be aware of these long-term risks of CAI use.

The study was limited by the amount of data about patient characteristics and lifestyle that could be obtained from the database as well as lack of data about systemic levels of CAIs after topical administration.