Pamidronate Disodium
Common Brand Names: Aredia
Therapeutic Class: Bone-resorption inhibitor
Common Injectable Dosage Forms:
Powder for Injection: 30 mg, 60 mg, and 90 mg per 10 mL vial
Dosage Ranges:
For the treatment of hypercalcemia of malignancy: Mild, asymptomatic hypercalcemia may be treated successfully with vigorous saline hydration therapy alone. Patients should be adequately rehydrated prior to administration. For moderate hypercalcemia (albumin-corrected serum calcium* 12-13.5 mg/dL), give 60 mg (diluted in 1000 mL of compatible solution^) as a single dose by intravenous infusion over 2-24 hours. For severe hypercalcemia (albumin-corrected serum calcium* ≥13.5 mg/dL), give 90 mg (diluted in 1000 mL of compatible solution^) as a single intravenous infusion over 2-24 hours. Longer infusions may reduce the risk for renal toxicity. A minimum of 7 days should elapse before retreatment.
For the treatment of Paget’s disease: 30 mg daily (diluted in 500 mL of compatible solution^), administered as a 4-hour infusion on 3 consecutive days.
For the treatment of osteolytic bone metastases of breast cancer: 90 mg (diluted in 250 mL of compatible solution^) administered as a 2-hour infusion every 3-4 weeks.
For the treatment of osteolytic bone lesions of multiple myeloma: 90 mg (diluted in 500 mL of compatible solution^) administered as a 4-hour infusion once every month.
*Albumin-corrected serum calcium (Cca. Mg/dL) = (0.8 x (4.0 - patient’s measured albumin in mg/dL)).
^Compatible solutions include 0.45% or 0.9% Sodium Chloride, USP, or 5% Dextrose Injection, USP.
Administration and Stability: Reconstituted by adding 10 mL of Sterile Water for Injection, USP to each vial (stable for 24 hours when stored at 2°-8°C (36°-46°F). The drug should be completely dissolved before the solution is withdrawn. Doses must be diluted prior to infusion (See Dosage Ranges). Calcium-containing infusion solutions, such as Lactated Ringer’s solution, must not be used. Doses should be administered as a single intravenous solution in a line separate from all other drugs.
Pharmacology/Pharmacokinetics: Pamidronate disodium inhibits bone reabsorption by adsorbing to calcium phosphate (hydroxyapatite) crystals in bone and may directly block dissolution of this mineral component of bone. It may also act by inhibiting osteoclast activity. Certain malignancies and metastatic bone disease cause hypercalcemia by stimulating osteoclast hyperactivity either through tumor invasion of bone or through other factors such as parathyroid-hormone-related protein. Excessive bone resorption spills calcium into the blood causing polyuria and GI distress and resulting in dehydration and a decrease in the glomerular filtration rate. Because hypoalbuminemia sometimes accompanies the hypercalcemia, an adjustment of serum calcium is used to determine the severity of the condition (See Dosage Ranges).
Drug and Lab Interactions: Use with caution with other nephrotoxic drugs.
Contraindications/Precautions: Contraindicated in patients with hypersensitivity to pamidronate or other bisphosphonates. Use with extreme caution in patients with severe renal impairment due to the risk of renal deterioration. Due to the risk of clinically significant deterioration in renal function, closely follow the approved dosing guidelines (See Dosage Ranges). Patients receiving Aredia should have serum creatinine assessed prior to each treatment. Patients should be well hydrated prior to treatment. Use with caution with other nephrotoxic drugs. Pregnancy Category D.
Monitoring Parameters: Serum calcium, electrolytes, phosphate, magnesium, CBC
Adverse Effects: Adverse effects to Aredia are usually mild and transient. The most common adverse effects are (in order of incidence): fever, anemia, myalgia, urinary tract infection, upper respiratory tract infection, dyspepsia, coughing, and abdominal pain. May also cause hypophosphatemia, hypokalemia, and hypomagnesemia.
Common Clinical Applications: Useful for treating hypercalcemia from malignancy and metastatic bone disease and for treating Paget’s disease.
