A message from Peter to our MS community
Recently, I visited one of our MS family members at Sunnybrook Hospital who was experiencing complete numbness in her arms and legs.
Approximately two weeks earlier, she had been dealing with a urinary tract infection (UTI). After taking an antibiotic, she began experiencing severe pain and weakness in her arms and legs. Her symptoms progressed to the point where she was unable to walk, and the pain became extremely difficult to manage.
I have also heard from several other members of our MS community who experienced significant symptoms after taking certain antibiotics for UTIs. While these experiences are concerning, it is important to recognize that individual experiences do not establish that a particular medication caused these symptoms or that the medication is unsafe for everyone with MS.
I am not a doctor or a medical professional. I am sharing what I have personally observed and heard within our community because I believe that the more informed we are, the better equipped we are to have meaningful conversations with our healthcare providers.
Antibiotics and MS: What Should You Know?
Some antibiotics, including medications in the fluoroquinolone class such as ciprofloxacin (Cipro) and moxifloxacin, have known potential side effects involving the nervous system, muscles, joints, and other parts of the body.
This does not mean that people with MS should avoid these medications or that they are responsible for every episode of weakness, pain, numbness, or difficulty walking following treatment.
However, because some symptoms associated with medication side effects can overlap with symptoms experienced by people living with MS, it is important to understand the potential risks and discuss them with a qualified healthcare professional.
If you are prescribed an antibiotic for a UTI, consider asking your doctor or pharmacist:
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What antibiotic am I being prescribed?
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Why is this particular antibiotic appropriate for my infection?
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What are the common and serious side effects?
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Could this medication affect my existing MS symptoms or other medications I take?
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Are there alternative treatments that may be appropriate?
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What symptoms should prompt me to contact my healthcare provider?
Antibiotics Commonly Used for UTIs
Depending on the type of infection, test results, allergies, medical history, and other individual factors, healthcare professionals may use different antibiotics to treat UTIs.
Examples include:
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Ceftriaxone — IV or injection in appropriate circumstances
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Fosfomycin (Monurol)
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Nitrofurantoin (Furadantin, Macrobid, Macrodantin)
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Sulfamethoxazole/trimethoprim (Bactrim, Bactrim DS)
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Amoxicillin/clavulanate (Augmentin) — in selected cases
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Cephalexin (Keflex) — in selected cases
The appropriate antibiotic varies from person to person. Do not start, stop, change, or substitute an antibiotic based solely on information in this article. Your healthcare provider can determine which treatment is appropriate for your particular infection.
Watch the Video
Peter has also shared a video discussing his concerns and observations regarding antibiotics and people living with MS.
A Reminder to Our MS Community
If you are living with MS and develop a UTI or another infection, speak with your healthcare provider about your treatment options and make sure they are aware of your MS diagnosis and any medications you are currently taking.
If you experience new or severe symptoms—including significant weakness, numbness, severe pain, difficulty walking, or other concerning changes—seek medical attention promptly.
This article is intended for general education and community awareness only. It is not medical advice and should not be used to diagnose, treat, or prevent any medical condition. Medication decisions should always be made in consultation with a qualified healthcare professional.
This article reflects the personal observations and concerns shared by a member of our MS community and does not necessarily represent the views of the organization.

