High incidence of hypocalcemia and serum creatinine increase in patients with bone metastases treated with zoledronic acid.
BACKGROUND
Zoledronic acid belongs to the new generation of bisphosphonates with demonstrated clinical benefit for the treatment of bone metastases from different kinds of neoplasms. Hypocalcemia and serum creatinine elevation are expected adverse events during this therapy. The monitoring of serum calcium and creatinine is therefore recommended. The primary aim of this study was to establish the actual incidence of hypocalcemia and serum creatinine elevation during treatment with zoledronic acid. Skeletal-related events and side effects were also assessed.


METHODS
Serum creatinine and calcium levels were evaluated in 240 consecutive patients (83 males, 157 females; mean age, 62 years) with metastatic bone lesions from different solid tumors treated with zoledronic acid.


RESULTS
Overall, 93 of 240 patients (38.8%) developed hypocalcemia, which was grade (G)1 in 45 patients (48.4%), G2 in 37 patients (39.8%), G3 in 10 patients (10.8%), and G4 in one patient (1.1%). The median time to occurrence of hypocalcemia (any grade) was 2.3 months after the beginning of the treatment (range, 0-34.9 months). Increased serum creatinine was observed in 33 of 240 patients (13.7%), of whom 19 had G1 (57.6%), 11 had G2 (33.3%), and three had G3 (9.1%). The median time to serum creatinine increase (for any grade) was 4.7 months (range, 0-29.2 months).


CONCLUSIONS
Our analysis shows a high incidence of hypocalcemia and increased serum creatinine level during treatment with zoledronic acid. These results strongly support the need for accurate monitoring of plasma calcium and creatinine levels.
Zuradelli
Monica
M
Dipartimento di Oncologia Medica ed Ematologia, Istituto Clinico Humanitas, Via Manzoni 56, Rozzano, Milan, Italy. monica.zuradelli@humanitas.it
Masci
Giovanna
G
Biancofiore
Giuseppe
G
Gullo
Giuseppe
G
Scorsetti
Marta
M
Navarria
Pierina
P
Tancioni
Flavio
F
Berlusconi
Marco
M
Giordano
Laura
L
Santoro
Armando
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000009:adverse effects*; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000556:secondary*; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood*; D004164:Diphosphonates / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000139:chemically induced / Q000453:epidemiology*; D007093:Imidazoles / Q000009:adverse effects*; D015994:Incidence; D007668:Kidney / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D012709:Serum Albumin / Q000032:analysis; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D012709:Serum Albumin; D000077211:Zoledronic Acid; D003404:Creatinine; D002118:Calcium