Do Certain Medications Increase the Risk of MS Development?

No drug treatments were conclusively associated with an increased risk of MS.

According to a new review published in Pharmacoepidemiology & Drug Safety, exposure to certain medications may potentially increase the likelihood of multiple sclerosis development, while others may have preventative effects.

The risk of MS has been tied to various environmental and lifestyle factors as well as some pharmacologic agents. To get a better understanding of the impact of prescription drug exposure on MS risk, researchers performed a systematic review of the literature which produced 13 articles that fit the inclusion criteria.

The results showed that MS was not associated with exposure to amiloride (adjusted hazard ratio [aHR] 1.34, 95% CI: 0.81–2.20) or valproic acid (aHR 1.30, 95% CI: 0.44–3.80). Oral contraceptives were not associated with MS in 4 studies but an increased risk was reported in 1 study (adjusted odds ratio [aOR] 1.52, 95% CI: 1.21–1.91). 

Penicillin exposure was associated with a decreased risk of MS development (aOR 0.5, 95% CI: 0.3–0.9), however, in a later study, all antibiotics (aOR 1.41, 95% CI: 1.29–1.53), including penicillin (aOR 1.21, 95% CI: 1.10–1.27) were associated with an increased risk. 

In patients with inflammatory bowel disease or arthritis, exposure to anti-tumor necrosis factor-alpha (TNFα) was not associated with increased MS risk, however, male patients exposed to anti-TNFα who also had arthritis and patients with ankylosing spondylitis were found to be at increased risk (standardized incidence ratios = 3.91; 95%CI:1.47–10.42 and 3.48;95%CI:1.45–8.37, respectively).

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Researchers also noted a lower risk of MS among patients exposed to fenoterol, a beta-2 adrenergic agonist (aOR 0.58, 95%CI: 0.45–0.76) and the sedating histamine 1-receptor antagonists (aOR 0.2, 95% CI: 0.1–0.8). This association was not evident for the non-sedating histamine 1-receptor antagonists (aOR 0.8, 95% CI: 0.4–1.6).

“No drug treatments were conclusively associated with an increased risk of MS, although uncertainty remains over anti-TNFα drugs and possibly antibiotics,” the authors concluded, “However, the suggestion that some drugs such as the sedating histamine 1-receptor blockers and beta2-adrenergic agonists may reduce the risk of MS onset is intriguing but requires replication.”

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