Could Iron Therapy Be the Cause of This Patient’s Bone Pain?

I had prescribed oral iron sulfate, 325 mg tid, for a 35-year-old woman with severe iron deficiency anemia. Soon after the patient started therapy, she complained of dull, aching, continuous bone pain that was localized to the sternal region, both upper arms, and both thighs, without radiation. The pain resolved after her hematocrit had risen above 34% and iron replacement therapy had been discontinued.

Could this patient’s bone pain have been a result of her iron therapy- perhaps caused by increased erythropoiesis?

-- MD

Bone pain from increased hematopoiesis is a well-known phenomenon that is seen, for example, in childhood leukemia. Moreover, bone pain is a common adverse effect of granulocyte colony-stimulating factor (G-CSF), which induces enhanced granulopoiesis. Such pain occurs in 22% of patients receiving G-CSF and can be a dose-limiting side effect.¹

However, bone pain is not associated with erythropoietin therapy. The 3% incidence of this effect in patients with cancer who were given erythropoietin is less than the 16% incidence seen in those who received placebo.² The symptom was not reported in patients who had undergone renal replacement. Finally, a canvass of my colleagues revealed no patients with bone pain in a collective experience of thousands who received erythropoietin therapy and a like number treated for iron deficiency.

Your case is intriguing, but data to support your hypothesis are sparse.

-- Ronald N. Rubin, MD
Professor of Medicine (Hematology)
Chief, Clinical Hematology
Temple University School of Medicine
Philadelphia

References:

REFERENCES:

1

. Neupogen (Filgrastim) Prescribing Information. Thousand Oaks, CA; Amgen Inc; 2007.

http://www.amgen.com/pdfs/misc/neupogen_pi.pdf

. Accessed November 14, 2008.

2

. Henke M, Laszig R, Rübe C, et al. Erythropoietin to treat head and neck cancer patients with anaemiaundergoing radiotherapy: randomised, double-blind, placebo-controlled trial.

Lancet.

2003;362:1255-1260.