Review Finds ‘No Strong Evidence’ Linking Medicines With ALS Risk
Data was reviewed for 171,407 people in 25 studies up to December 2021
There is no compelling evidence to suggest any medication increases the risk of developing amyotrophic lateral sclerosis (ALS), according to a review of published studies.
If anything, classes of drugs including anti-hypertensives, cholesterol-lowering statins, aspirin, and oral contraceptives may be associated with a lower risk of ALS, although several studies found no association whatsoever with disease risk.
The study, “Medication use and risk of amyotrophic lateral sclerosis—a systematic review,” was published in BMC Medicine.
Scientists at the Karolinska Institutet, Sweden reviewed the published scientific literature to assess what is known about medication use and ALS risk in what they described as “the first systematic review to evaluate the association between medication use and subsequent risk of ALS.”
The review included 25 studies published up to December 2021 and covering data for 171,407 people with ALS. Medications that were assessed included cholesterol-lowering medicines, anti-inflammatory therapies, immune-suppressing treatments, antibiotics, oral contraceptives, hormone replacement therapy (HRT), medications used to manage high blood pressure or diabetes, and therapies for psychiatric and neurological disorders.
The researchers noted much inconsistency from study to study with many having contradictory findings.
“We found that there was generally a lack of agreement on the associations of these medications with the subsequent risk of ALS between studies,” they wrote.
For some medications, namely aspirin, oral contraceptives, HRT, high blood pressure therapies, diabetes treatments, and cholesterol-lowering medicines called statins, the available studies either did not show any association with ALS risk or indicated it may be lower in people using these treatments.
Based on these data, the researchers concluded that these therapies are “unlikely related to a higher risk of ALS,” though they emphasized that interpreting “these results should be done with caution as most of the studies examined broad categories of these medications, leaving the potentially harmful role of specific drug classes unraveled.”
Several studies noted an association between ALS risk and antibiotics, antidepressants, and muscle relaxants. The researchers said these associations are probably “attributable to prodromal ALS symptoms or reverse causation,” however. In other words, it’s likely that people with ALS were using these medications more frequently in order to help manage early symptoms of the disease before being formally diagnosed.
The scientists concluded “there is currently no strong evidence to link any medication use with ALS risk.”
The team noted that an inherent limitation in looking for associations between medication use and disease risk is the so-called “indication bias,” wherein it’s not clear whether a given association may be due to the use of a medication or the underlying condition itself.