118072-93-8

Description

Zoledronic acid is a white, crystalline powder that is available in vials for reconstitution for IV infusion over at least 15 minutes. It does not undergo metabolic transformation and does not inhibit CYP450 enzymes. Clearance of this agent is dependent on the patient's creatinine clearance, not on dose. Serum creatinine levels should be evaluated before every treatment. Zolendronic acid is contraindicated in patients with severe renal impairment.

Chemical Properties

White Solid

Originator

Zometa,Novartis Pharma,Switz

Uses

Bisphosphonate antiresorptive agent

Definition

ChEBI: An imidazole compound having a 2,2-bis(phosphono)-2-hydroxyethane-1-yl substituent at the 1-position.

Manufacturing Process

With stirring and under reflux, 8.6 g (0.053 mole) of imidazol-4-yl acetic acid hydrochloride, 7.1 ml of 85% phosphoric acid and 25 ml of chlorobenzene are heated to 100°C. Then 13.9 ml of phosphorus trichloride are added dropwise at 100°C, whereupon evolution of gas occurs. Over the course of 30 min a dense mass precipitates from the reaction mixture. The batch is heated for 3 hours to 100°C and the supernatant chlorobenzene is removed by decantation. With stirring and under reflux, the residual viscous mass is heated to the boil for 3 hours with 40 ml of 9 N hydrochloric acid. The batch is filtered hot with the addition of carbon and the filtrate is diluted with acetone, whereupon the crude 2-(imidazol-4-yl)-1-hydroxy-ethane-1,1- diphosphonic acid precipitates. This product is recrystallised from water. Melting point: 238-240°C (dec.).

Brand name

Zometa (Novartis).

Therapeutic Function

Bone calcium regulator

Biological Functions

Zoledronic acid, a bisphosphonate, was approved by the U.S. FDA in 2001 for the treatment of hypercalcemia of malignancy, a metabolic complication that can be life-threatening. Hypercalcemia of malignancy can occur in up to 50% of patients diagnosed with advanced breast cancer, multiple myeloma, and nonsmall cell lung cancer. This condition arises when chemical moieties produced by the tumor cause overstimulation of osteoclasts. When there is an increase in bone degradation, there is a concomitant release of calcium into the plasma. When serum concentrations of calcium rapidly elevate, the kidneys are unable to handle the overload, and hypercalcemia results. This can lead to dehydration, nausea, vomiting, fatigue, and confusion. Zoledronic acid effectively decreases plasma calcium concentrations via inhibition of bone resorption (inhibition of osteoclastic activity and induction of osteoclast apoptosis). It also prevents the increase in osteoclastic activity caused by tumor-based stimulatory factors. Additionally zoledronic acid has been approved by the U.S. FDA for the treatment of multiple myeloma and bone metastases associated with solid tumor–based cancers (e.g., prostrate and lung). This agent is currently in late-stage clinical trials for the treatment and prevention of osteoporosis and, if approved, will be formulated as a 5-mg, once-yearly IV infusion.

Clinical Use

Zoledronic acid is most commonly given to patients whose cancer is no longer responding to hormones, but it also may be given to prevent the bone thinning and weakening that results from hormonal treatments.

Drug interactions

Potentially hazardous interactions with other drugs Other nephrotoxic drugs: use with caution as can enhance nephrotoxicity

Metabolism

Zoledronic acid is not metabolised and is excreted unchanged via the kidney. Over the first 24 hours, 39 ± 16% of the administered dose is recovered in the urine, while the remainder is principally bound to bone tissue.