Magnesium oxide tablets form rigid masses in xanthan gum-based thickeners: A physicochemical hazard revealed by a clinical case.
Soichi Makino, Miyu Ooe, Kazunari Miyazawa et al.
✦ AI-curated · Sources linked
Case in brief
An older adult with a malignant esophageal stricture developed acute esophageal obstruction from a foreign body identified as a swollen, non-disintegrated magnesium oxide (MgO) tablet. Ex vivo imaging and chemical analysis supported the identification. In a static immersion model, all four tested MgO formulations failed to disintegrate in every tested combination with xanthan gum-based thickeners; at 2.0–3.0% thickener, tablet weight increased by approximately 2.2-fold and rigid masses formed. The tablets disintegrated in swallowing-aid jelly in approximately 25 s, but it cost approximately 14.5-fold more per administration than thickeners.
What made this case unusual
The obstruction was linked to a physicochemical interaction: xanthan gum-based thickener prevented MgO tablet disintegration and produced a swollen, rigid mass, a hazard that may be overlooked when thickened fluids are treated as inert swallowing aids.
Diagnostic / clinical pearl
In a patient with dysphagia and esophageal obstruction, consider a medication–thickener interaction. Xanthan gum-based thickeners prevented disintegration of all tested MgO formulations in the study’s immersion model.
Why it matters
The reported cost difference—swallowing-aid jelly was approximately 14.5-fold more expensive per administration—may be a barrier to adopting an alternative vehicle, despite the potential mechanical hazard.