Tolterodine, solifenacin, oxybutynin use tied to increased risk of dementia
Subsequent dementia is associated with taking tolterodine, solifenacin and particularly oxybutynin in patients with diabetes mellitus, a new study shows.
The study retrieved records of 10,938 patients who had received at least one type of oxybutynin, tolterodine or solifenacin from the Taiwan National Health Insurance Research Database. An age-, sex- and index date-matched control cohort was established on a 1:1 ratio. Those diagnosed with dementia before the index date or within 180 days were excluded.
Comorbidities included in the analysis were hypertension, lipid disorders, atrial fibrillation, chronic kidney diseases, coronary artery disease and heart failure.
Dementia was reported in 7,774 at the end of the follow-up period. For the oxybutynin, solifenacin and tolterodine groups, the 6-year dementia rates were 3.9, 4.3 and 2.2 percent, respectively. These rates were significantly different compared with the control group (1.2 percent; p<0.001).
After age- and sex-matching, only 2,540 patients were eligible for analysis. The 6-year dementia rates for this group decreased for oxybutynin (3.0 percent) and solifenacin (3.5 percent). Interestingly, the rate increased in controls (2.4 percent) to a level that was higher than that reported in tolterodine users (2.3 percent).
According to the failure curve, dementia was significantly more likely to occur in patients who took oxybutynin, solifenacin or tolterodine (p<0.001 for all).
After adjusting for confounders, the competing-risk regression model showed that those who received oxybutynin (adjusted hazard ratio [aHR], 2.35; 95 percent CI, 1.96 to 2.81), solifenacin (aHR, 2.16; 1.81 to 2.58) and tolterodine (aHR, 2.24; 1.85 to 2.73) were at higher risks of dementia, with death as the competing event. Of the three drugs, solifenacin showed the lowest risk.