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Washington University Experience | MUSCLE | Autophagic myopathy | 9B AANP199-02 Omeprazole EM Bilbao
The ultrastructural appearance consists of autophagic vacuoles. (electron micrographs) ---- Comment by the authors: On EM there were myelin bodies and extruded Iysosomes, as well as glycogen granules which however were not incorporated into the Iysosomes. No curvilinear bodies were found. Congo red stain exhibited threads in the affected fibers. Some people at the diagnostic slide session thought that the picture was that of inclusion body myositis, but it was pointed out that in Japan, Congo red positive material has been described in muscle fibers in chloroquine myopathy, which this case resembles. The patient's symptoms subsided following cessation of omeprazole treatment, and they recurred after rechallenge, with elevation of serum CK. ---- Additional information: Omeprazole myopathy is a rare, sometimes severe adverse reaction characterized by muscle disease in patients taking the proton pump inhibitor (PPI) omeprazole (Prilosec). Patients typically experience muscle pain, tenderness, and weakness (most often in the shoulders, thighs, or legs). In very rare and severe cases, it can escalate to rhabdomyolysis—a life-threatening breakdown of muscle tissue that releases muscle proteins into the bloodstream and can cause acute kidney injury. A role for hypomagnesemia from impaired absorption of magnesium from the intestine has been proposed to produce the disease. In rare instances, omeprazole may trigger an immune response (such as polymyositis) particularly if it is taken with statins .
