What is the dosing for Reclast (zoledronic acid)?

Reclast (Zoledronic Acid) Dosing

Standard Dosing for Osteoporosis

For osteoporosis treatment, Reclast is administered as 5 mg intravenously once per year, infused over at least 15 minutes. 1, 2

• The infusion must be given over no less than 15 minutes to minimize acute phase reactions and renal toxicity 1, 2
• Treatment duration is typically 5 years, with consideration for discontinuation after 3-5 years if bone mineral density is stable and short-term fracture risk is low 1
• For patients with high fracture risk, extending treatment up to 6 years may be appropriate 1

Dosing for Cancer-Related Bone Disease

For multiple myeloma and bone metastases from solid tumors, the dose is 4 mg intravenously every 3-4 weeks, infused over at least 15 minutes. 3, 2

• This lower dose (4 mg vs 5 mg for osteoporosis) is used for cancer patients with bone involvement 3, 2
• Treatment should continue for up to 2 years, with less-frequent dosing (every 12 weeks) considered in patients with responsive or stable disease 3
• At disease relapse with new skeletal-related events, resume treatment on the every 3-4 week schedule 3

Renal Dose Adjustments

Dose reduction is required for patients with baseline creatinine clearance ≤60 mL/min when treating cancer-related bone disease: 3, 2

• CrCl 50-60 mL/min: 3.5 mg 2
• CrCl 40-49 mL/min: 3.3 mg 2
• CrCl 30-39 mL/min: 3.0 mg 2
• Zoledronic acid is contraindicated if creatinine clearance is <30-35 mL/min 1, 4, 2

For osteoporosis treatment (5 mg annual dose), no specific dose adjustments are provided in guidelines, but the drug should not be used in severe renal impairment 2

Special Population Dosing

For premenopausal women on aromatase inhibitors with ovarian suppression, use 4 mg every 6 months to prevent rapid bone loss. 1, 4

• For postmenopausal women on aromatase inhibitors, either 4 mg every 6 months or the standard 5 mg annually can be used 1, 4
• For osteopenia in high-risk patients, 5 mg every 2 years may be considered, though this is not FDA-approved 1, 4

Pre-Treatment Requirements

Before administering Reclast, the following must be completed: 1, 4

• Correct vitamin D deficiency to avoid severe hypocalcemia 1, 4
• Ensure adequate calcium supplementation (500 mg daily) and vitamin D (400 IU daily) 2
• Complete dental examination and any necessary dental work to reduce osteonecrosis of the jaw risk 1, 4
• Measure serum creatinine to assess renal function 1, 4
• Ensure adequate hydration before infusion 2

Monitoring During Treatment

Monitor serum creatinine before each dose. 3, 1, 4

• Withhold treatment if unexplained creatinine increase occurs (≥0.5 mg/dL in patients with normal baseline, or ≥1.0 mg/dL in patients with abnormal baseline) 2
• Resume treatment only when creatinine returns to within 10% of baseline value 2
• Monitor serum calcium, especially in patients at risk for hypocalcemia 2

Critical Pitfalls to Avoid

Never infuse faster than 15 minutes—this significantly increases the risk of acute phase reactions and renal toxicity. 1, 4, 2

• Do not use in patients with uncorrected hypocalcemia or severe vitamin D deficiency 1, 2
• Do not exceed 4 mg per dose for cancer patients or 5 mg per dose for osteoporosis patients 2
• Do not mix with calcium-containing solutions or administer through the same IV line as other medications 2
• Do not use Reclast (5 mg osteoporosis formulation) interchangeably with Zometa (4 mg cancer formulation)—they are different products with different indications 2