Prescribing of zoledronic acid in a tertiary outpatient hospital setting

Zoledronic acid (ZA) is an intravenous bisphosphonate approved for the prevention and treatment of cancer skeletal-related events.

Our aim was to analyze the prescription patterns of ZA in the cancer outpatient clinic.

We performed a retrospective chart review of all patients who received at least 1 dose of ZA from January 2009 until December 2010 in our institution. The patients' follow-up period was defined from the administration of the first dose until February 2011.

The sample comprised 345 patients: 31.9 % had breast cancer, 14.5 % prostate cancer, 29.0 % multiple myeloma, and 24.6 % other solid tumors. A total of 4,546 doses were administered; 2,749 (60.5 %) without intravenous chemotherapy. 71.1 % of patients with breast cancer, 86 % with prostate cancer, 60 % with multiple myeloma and 44.6 % with other solid tumors, received ZA without intravenous chemotherapy throughout bisphosphonate treatment. Doses were adjusted in one-third of cases. Administration every 4-weeks was the most frequent schedule. Median duration of treatment varied between 15.0 months for breast cancer and 4.2 months for other solid tumors.

Most of ZA prescriptions in cancer outpatients followed the labeled indications. The percentage of ZA doses administered without intravenous chemotherapy was 60.5 %.