Rheumatoid arthritis drugs and the risk of Parkinson’s disease – a meta-analysis

Abstract Introduction Several observational studies reported an association between Rheumatoid Arthritis (RA) and the subsequent risk of developing Parkinson’s disease (PD). However, whether the drugs commonly prescribed for RA contribute to this association remains controversial. Content We sought to summarize all the published evidence regarding the association between the drugs used for RA and the risk of developing PD as well as to explore the potential neuroprotective and therapeutic potential of these drugs for PD patients. We searched three electronic biomedical databases (namely, PubMed, Scopus, and Web of Science) to find potentially relevant studies. The outcome of interest was the relative risk (RR) of developing PD in individuals taking any of these drugs: (1) non-steroidal anti-inflammatory drugs (NSAIDs), (2) acetaminophen, (3) corticosteroids, and (4) disease-modifying anti-rheumatoid drugs (DMARDs), compared to individuals not taking them. Summary and outlook 26 studies (15 case-control and 11 cohort) were included in the analysis with a total number of 4,321,104 participants including 150,703 PD cases. Analysis showed a statistically significant lower risk of developing PD among individuals who received corticosteroids (RR 0.80, 95% CI 0.77 – 0.84, P< 0.00001) and DMARDs (RR 0.69, 95% CI 0.55 – 0.86, P <0.001). Subgroup analysis by individual drugs showed a decreased risk with dexamethasone (RR 0.69, 95% CI 0.60 – 0.79, P <0.00001) and hydroxychloroquine (RR 0.77, 95% CI 0.66 – 0.90, P <0.001). Our findings showed that individuals who were treated with corticosteroids (especially dexamethasone) and DMARDs (especially hydroxychloroquine) have reduced risk of developing PD compared to those not receiving these medications.