Antibiotic usage may increase the risk of developing amyotrophic lateral sclerosis (ALS), with a higher number of prescriptions linked to greater risk, a new study in the European Journal of Neurology suggests.
The researchers conducted a nested case control study investigating antibiotic dispensing to a total of 2484 Swedish ALS patients before they were diagnosed with the disease, against 12,420 healthy matched controls, between 2006 and 2013.
After accounting for potential diagnostic delay in ALS by excluding all prescriptions within one year before diagnosis, any antibiotic use was associated with a higher risk of developing ALS.
The ORs (95% CIs) were 1.06 (0.94-1.19), 1.13 (1.00-1.28), and 1.18 (1.03-1.35) when comparing 1, 2 to 3, and ≥4 prescriptions to no prescription (P for trend=0.0069).
Similar results were noted for antibiotics used for respiratory infections and urinary tract as well as skin and soft tissue infections.
Among different individual antibiotics, the risk of ALS was especially increased in relation to more than two prescriptions of beta-lactamase sensitive penicillin (OR=1.28; 95% CI 1.10-1.50).
The study authors believe this is the first population-based study to assess the link between antibiotics use and future risk of ALS and cautioned that additional evidence is needed before a causal relationship can be claimed.