Bisphosphonate pearl (thanks to Jess Neil for sharing this): if someone has underlying and unrecognized Vit D deficiency, hypoparathyroidism or impaired renal function, giving a bisphosphonate (even when treating hypercalcemia) can precipitate severe hypocalcemia since the body does not have the normal compensatory mechanisms to correct if the bisphosphonate overshoots the reduction in calcium.
How does myeloma affect the kidney? There is a huge list but here are the main mechanisms
- Myeloma cast nephropathy: all those proteins collect as casts and can cause tubular injury (remember that Tamm-Horsfall thing?)
- Amyloidosis: increased AL amyloid production takes place in mesangial cells causing damage to the glomerulus
- Immunoglobulin deposition disease: similar mechanism of damage to amyloid, where immunoglobulin deposits in the glomerulus
Hypercalcemia: check out these blog posts from earlier to get some more learning about treatment and work-up of hypercalcemia!