Zoledronic Acid

What it is and how it works

Mechanism of Action Zoledronic acid injection is a bisphosphonate and acts primarily on bone. It is an inhibitor of osteoclast-mediated bone resorption. The selective action of bisphosphonates on bone is based on their high affinity for mineralized bone. Intravenously administered zoledronic acid rapidly partitions to bone and localizes preferentially at sites of high bone turnover. The main molecular target of zoledronic acid in the osteoclast is the enzyme farnesyl pyrophosphate synthase. The relatively long duration of action of zoledronic acid is attributable to its high binding affinity to bone mineral.

Indications

Zoledronic acid injection is a bisphosphonate indicated for: • Treatment and prevention of postmenopausal osteoporosis ( 1.1 , 1.2 ) • Treatment to increase bone mass in men with osteoporosis • Treatment and prevention of glucocorticoid-induced osteoporosis • Treatment of Paget’s disease of bone in men and women Limitations of Use Optimal duration of use has not been determined. For patients at low-risk for fracture, consider drug discontinuation after 3 to 5 years of use Treatment of Osteoporosis in Postmenopausal Women Zoledronic acid injection is indicated for treatment of osteoporosis in postmenopausal women. In postmenopausal women with osteoporosis, diagnosed by bone mineral density (BMD) or prevalent vertebral fracture, zoledronic acid injection reduces the incidence of fractures (hip, vertebral, and non-vertebral osteoporosis-related fractures). In patients at high risk of fracture, defined as a recent low-trauma hip fracture, zoledronic acid injection reduces the incidence of new clinical fractures .

Dosage and administration (summary)

Infusion given intravenously over no less than 15 minutes: • Treatment of postmenopausal osteoporosis ; treatment to increase bone mass in men with osteoporosis : treatment and prevention of glucocorticoid-induced osteoporosis : 5 mg once a year • Prevention of postmenopausal osteoporosis: 5 mg once every 2 years • Treatment of Paget’s disease of bone: a single 5 mg infusion. Patients should receive 1500 mg elemental calcium and 800 international units vitamin D daily Important Administration Instructions Zoledronic acid injection must be administered as an intravenous infusion over no less than 15 minutes.

Contraindications

Zoledronic acid injection is contraindicated in patients with the following conditions: • Hypocalcemia • Creatinine clearance less than 35 mL/min and in those with evidence of acute renal impairment due to an increased risk of renal failure . • Known hypersensitivity to zoledronic acid or any components of zoledronic acid injection. Hypersensitivity reactions, including urticaria, angioedema, and anaphylactic reaction/shock have been reported .

Warnings and precautions

• Products Containing Same Active Ingredient: Patients receiving Zometa ® should not receive zoledronic acid injection • Hypocalcemia may worsen during treatment. Patients must be adequately supplemented with calcium and vitamin D • Renal Impairment: A single dose should not exceed 5 mg and the duration of infusion should be no less than 15 minutes. Renal toxicity may be greater in patients with underlying renal impairment or with other risk factors, including advanced age or dehydration.

Pregnancy

Pregnancy Risk Summary Available data on the use of zoledronic acid injection in pregnant women are insufficient to inform a drug-associated risk of adverse maternal or fetal outcomes. Discontinue zoledronic acid injection when pregnancy is recognized.

Storage and supply

Zoledronic Acid Injection is supplied as follows: Each vial contains 5 mg/100 mL NDC 67457-619-10 Handling After opening the solution, it is stable for 24 hours at 2° to 8°C (36° to 46°F). If refrigerated, allow the refrigerated solution to reach room temperature before administration. Storage Store at 20° to 25°C (68° to 77°F).

Source: Zoledronic Acid (Zoledronic Acid) — US FDA prescribing information, 2026-03-16, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.