Background Zoledronic acid is a bisphosphonate indicated for the prevention of skeletal-related events in patients with advanced malignancies involving bone and treatment of hypercalcaemia of malignancy. According to data sheet Zometa isn't recommended for patients presenting with severe renal impairment (CrCl <30 ml /min) prior to initiation of therapy. Following initiation of therapy, serum creatinine should be measured and the dose adjusted according to creatinine clearance value. Treatment should be withheld if renal function deteriorates.

Purpose To assess the technical suitability of treatments with zoledronic acid 4 mg (Zometa) in terms of indication and dosage adjustment according to the renal function of patients in the Oncology Department of a General Hospital.

Materials and methods The authors performed a retrospective study (January 2009 to December 2010) in which creatinine values of patients were collected (n=83). Renal clearance was calculated by the Cockcroft-Gault formula in each case to evaluate the renal function status and see if dose adjustment was necessary. The authors also collected demographic data and the diagnosis to check that the indication for the drug was correct.

Results

• ▶ In 28.91% of patients, serum creatinine values were not obtained before the first dose.

• ▶ 30.12% of patients (60% women and 40% men) required a dose adjustment sometime during the treatment. Of these, 68% were older than 65.

• ▶ 24.09% of patients experienced a worsening of renal clearance at some point during treatment, 25% of which was bad enough to require dose adjustment in subsequent administrations.

• ▶ One of the patients received two doses separated by a time interval below the minimum (3-4 weeks).

• ▶ The main diagnoses were: breast cancer (45.78%), lung (19.27%) and prostate cancer (16.86%).

Conclusions The authors concluded that it is important to introduce a standard procedure for the use of zoledronic acid 4 mg and assess the need for dose adjustment as the data sheet recommends, considering the possible adverse effects that the treatment can produce.