PamidronateRx

Trade Names: Aredia

Drug Class: Bisphosphonate

Preparations: : 30- and 90 mg for injection

Dose
Paget’s disease: 30 mg as a dilute intravenous infusion over 4 hours once daily for 3 days
Hypercalcemia of malignancy: 60–90 mg as a slow infusion over 4–24 hours; may need to be repeated at 2- to 3-week intervals

Indications: Hypercalcemia of malignancy, Paget’s disease

Mechanism of Action: Localizes to areas of bone resorption and inhibits osteoclast activity

Contraindications: Hypersensitivity, hypocalcemia, not recommended for patients with severe renal insufficiency (creatinine clearance <35 mL/min)

Precautions: Use caution in renal impairment. A dental exam and preventive dental work should be performed before starting bisphosphonate therapy.

Monitoring: Monitor serum electrolytes periodically.

Pregnancy Risk: D

Adverse Effects
Common: Fever, arthralgia, flu-like syndrome, fatigue, headache, nausea, vomiting, hypocalcemia, hypokalemia, hypomagnesemia, nausea, diarrhea, bone pain, dyspnea, thrombophlebitis at infusion site
Less common: Rash, hypersensitivity, leukopenia, infusion reaction, atypical subtrochanteric femur fractures, osteonecrosis of the jaw, severe musculoskeletal pain, uveitis, altered taste, urticaria, angioedema, atrial fibrillation, severe hypocalcemia, impaired renal function

Drug Interactions
Diuretics: Increased risk of electrolyte abnormalities

Comments: Supplemental calcium and vitamin D are usually administered. Premedication and treatment with acetaminophen  often used to  decrease flu-like symptoms associated with infusion.

Clinical Pharmacology: Renal excretion. Plasma half-life is relatively short (24 hours), but bone half-life is  much longer (months or years)  indicating localization and release from bone.

Cost: $$

BIBLIOGRAPHY

Ralston SH. Clinical practice. Paget's disease of bone. N Engl J Med 2013;368:644-50. PMID: 23406029