Multiple courses of penicillin antibiotics were associated with a modestly reduced risk of Parkinson's disease (PD), while antifungal medications were linked to slightly increased PD risk, according to a large UK population-based study published in Parkinsonism and Related Disorders.
In the study of 12,557 PD cases and 80,804 matched controls, patients who received 5 or more courses of penicillins had lower odds of developing PD across multiple periods of 1-5 years and 6-10 years. Conversely, patients receiving 2 or more courses of antifungal medications in the preceding 1-5 years showed modestly increased odds of PD diagnosis.
The nested case-control study, using the Clinical Practice Research Datalink, examined antimicrobial prescriptions during three time windows: 1-5, 6-10, and 11-15 years before PD diagnosis. The study population had a median follow-up of 26.0 years for cases and 25.3 years for controls, with a mean age of 73.6 years for PD cases and 73.4 years for controls.
Clinical characteristics differed between groups in expected ways. PD cases showed higher rates of constipation and anosmia. Controls had higher rates of COPD and more frequent respiratory infections.
Macrolide antibiotics showed an inverse but non-significant association with PD risk in the 1-5 year period. Cephalosporins demonstrated a pattern similar to penicillins but without reaching statistical significance. No clear relationship emerged between tetracycline exposure and PD risk.
The study had several methodological limitations. COPD served as a surrogate marker for smoking status. Hospital and emergency room antibiotic prescriptions were not captured. The analysis could not account for antibiotic residues in food or stratify penicillins by spectrum of activity. Additionally, PD diagnoses came from general practitioner records rather than specialist confirmation.
This research was supported by the Parkinson's Foundation. The study authors reported no relevant financial disclosures. Conflict of interest disclosures can be found in the study.
