Are fibromyalgia and irritable bowel syndrome related to medication sensitivity?

Published: January 24, 2024

Medications can affect patients in many ways, ranging from life threatening allergic reactions to uncomfortable side effects. Patients who have frequent side effects from many different medications may have multiple drug intolerance syndrome (MDIS). This can complicate treatment options for patients, as physicians try to work around medication side effects. There has been anecdotal association of MDIS with fibromyalgia and irritable bowel syndrome (IBS). Much like MDIS, fibromyalgia and IBS can be diagnosed by a patient’s reported symptoms, even if various tests and procedures are normal.

In a recent publication of The Journal of Allergy and Clinical Immunology: In Practice, the relationship between MDIS, fibromyalgia and IBS was evaluated. Alvarez and colleagues used the electronic medical record system to identify patients diagnosed with fibromyalgia and IBS. Then, their reported drug allergies and other demographic characteristics were analyzed. Patients with over 10 drug allergy labels in their medical record were considered to have severe MDIS. Listed reactions to medications were also evaluated.

Patients with fibromyalgia were twelve times more likely to have severe MDIS than healthy controls. Patients with IBS were three times more likely to have severe MDIS than healthy controls. Having 15 or more active medications in the patient’s medical record was associated with severe MDIS in all patients. Opiates were the most frequently reported drug allergy among all participants. Penicillin and sulfonamide antibiotics were the most frequently reported antibiotic allergies. Rash and hives were the most frequently reported reaction to medications.  This was followed by gastrointestinal symptoms and itching. Overall, those with IBS were more likely to report gastrointestinal symptoms as side effects of medications. However, patients with fibromyalgia did not report side effects of pain or mood changes more often than controls, even though these are symptoms of fibromyalgia.

Further evaluation is needed to understand which patients with fibromyalgia or IBS are at increased risk for developing MDIS, and whether this can be attenuated or prevented, possibly by reducing the number of active medications prescribed to these patients.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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