Effect of DOPA decarboxylase inhibitor supplements on the incidence of urinary tract infections in Parkinson’s disease patients: A systematic review and meta-analysis of randomized controlled trials

Objectives: Parkinson’s disease is the most common neurodegenerative disease. Combining levodopa with other drugs, including decarboxylase inhibitors (DCI) is its most effective treatment. Urinary tract infection (UTI) is the most common cause of hospitalization in Parkinson’s patients, making it crucial to find an appropriate treatment to reduce the incidence of this complication. This study aimed to investigate UTIs in Parkinson’s patients using levodopa with DCI supplements. Methods: In this systematic review and meta-analysis, databases such as PubMed, Scopus, Embase, Cochrane, and Web of Science were searched up to March 2024. Only randomized controlled trials involving Parkinson’s patients were included in the present study. Parkinson’s patients who used levodopa along with carbidopa or benserazide were considered the intervention group, while those who used levodopa with another drug were considered the control group. Results: Nine interventional studies were ultimately analyzed. The relative risk (RR) of UTI in patients taking DCI was 26% lower than those who did not (RR Treatment/Control = 0.74, 95% CI: 0.58-0.95, p = 0.019). Furthermore, observations at different times of follow-up showed that at 13-24 weeks and at > 24 weeks of treatment with DCI, there was a reduction in the incidence of UTI (RR = 0.68, 95% CI: 0.46-1.01 and RR = 0.77, 95% CI: 0.58-1.0, respectively). On the contrary, there was an increase of the risk of UTI in the first 12 weeks of treatment with DCI (RR = 1.11, 95% CI: 0.37-3.33). Conclusions: The results of this study indicated that using DCI drugs is associated with a reduced relative risk of developing UTIs. The beneficial effect of the drug showed after 12 weeks of treatment after an initial negative effect on the risk of UTI.