Low risk of severe adverse reactions after oral carbonic anhydrase inhibitors prescription

In this population-based analysis, the risk of a serious adverse reaction with the use of oral or topical carbonic anhydrase inhibitor in clinical care was low, suggesting the reluctance of prescribing an oral carbonic anhydrase inhibitor should be reconsidered.

In this study, 128,942 patients who initiated an oral or topical carbonic anhydrase inhibitor during the 25-year study period were matched 1-to-1 based on age, sex, and diabetes status were followed for the first 120 days after the first identified prescription. Approximately 19% of patients had a diagnosis of diabetes.

Patients prescribed oral and topical carbonic anhydrase inhibitor had an absolute risk of a severe complicated adverse event of 2.90 per 1000 patients and 2.08 per 1000 patients, respectively. This difference between groups was equivalent to a risk ratio of 1.40, with a number needed to harm of 1 in 1220 patients (95% CI, 1.12-1.74; P = .003).

When controlling for confounding factors the low risk remained.

Patients with more comorbidities and those with more frequent clinic contacts were at additional risk for a severe complicated adverse event.

Reference
Popovic MM, Schlenker MB, Thiruchelvam D, et al. Serious Adverse Events of Oral and Topical Carbonic Anhydrase Inhibitors. JAMA Ophthalmol. Published online January 27, 2022. doi:10.1001/jamaophthalmol.2021.5977