IH Registry Study Finds Kidney Stones Are NOT A Common Side Effect of Daily Acetazolamide Treatment
IH Registry Study Finds Kidney Stones Are NOT A Common Side Effect of Daily Acetazolamide Treatment
A new study from the IH Registry, to be published in an upcoming 2016 issue of the Journal of Neuro-Ophthalmology, examines daily acetazolamide (Diamox) use and its relationship to calcium phosphate kidney 
stones (nephrolithiasis), and compared the clinical presentation of IIH in the patients in the study who developed kidney stones with those who did not develop kidney stones.
Previous research has suggested that acetazolamide increased the risk of kidney stones, especially with long-term use. The case-control study looked at data from a total of 670 IIH patients enrolled in the IH Registry—the largest sampling of IIH patients in such a study to date. Nineteen (19) patients were identified as meeting the case definition of developing a calcium phosphate kidney stone during acetazolamide treatment for IIH. From the remaining pool of eligible participants, 40 controls were randomly selected.
Among all eligible patients, 19 (2.8%) of the 670 developed a stone during acetazolamide treatment for IIH. Within this group, 17 (89.5%) of 19 developed a stone within 1.5 years of initial daily acetazolamide treatment. Daily acetazolamide use was not significantly related to stone development (odds ratio = 0.95; 95% confidence intervals: 0.86-1.05). Additionally, the relationship between the clinical presentation of IIH at the time of diagnosis (signs and symptoms) and stone development did not reach statistical significance (P > 0.05).
The study discovered that overall, for IIH patients, kidney stone formation during acetazolamide treatment is a relatively rare event. Additionally, there is no evidence to support a direct association between acetazolamide daily dosage and kidney stone development. For IIH patients who do develop a stone while being treated with acetazolamide, formation is likely to occur within the first year and a half. Finally, the researchers found that there are no unique IIH disease features (signs and symptoms) at the time of diagnosis that are associated with kidney stone development
While these findings are welcome news, IH patients on daily acetazolamide treatment should still be carefully monitored for kidney issues and stone formation, especially in the first year and a half of treatment.
For more on information on the study, please read the Pubmed abstract.