Pamidronate disodium
Pamidronate disodium (Aredia)
Pamidronate disodium
(pah- MIH-droh-nayt)
Pregnancy Category: C Aredia (Rx)

Classification: Bone growth regulator, antihypercalcemic

Action/Kinetics: Inhibits both normal and abnormal bone resorption without inhibiting bone formation and mineralization. Precise mechanism is not known, but the drug may inhibit dissolution of hydroxyapatite crystal or have an effect on bone reabsorbing cells. Causes decreased serum phosphate levels probably due to a decreased release of phosphate from bone and increased renal excretion as parathyroid levels return to normal. Urinary calcium/creatinine and urinary hydroxyproline/creatinine ratios decrease and usually return to normal or below normal after treatment. t 1/2: Biphasic, 1.6 hr (alpha) and 27.3 hr (beta). Approximately 50% of an IV infused dose is excreted unchanged in the urine within 72 hr.

Uses: In conjunction with hydration to treat moderate to severe hypercalcemia associated with malignancy (with or without bone metastases). Moderate to severe Paget's disease. In conjunction with antimyeloma chemotherapy to treat osteolytic bone lesions of multiple myeloma or osteolytic bone metastases of breast cancer. Investigational: Postmenopausal osteoporosis; hyperparathyroidism; prophylaxis of glucocorticoid-induced osteoporosis; reduce bone pain in clients with prostatic carcinoma; treat immobilization-induced hypercalcemia.

Contraindications: Hypersensitivity to biphosphonates.

Special Concerns: Use with caution during lactation. Safety and effectiveness have not been determined in children. Pamidronate has not been tested in clients who have creatinine levels greater than 5 mg/dL.

Side Effects: Metabolic/Electrolytes: Hypocalcemia, hypokalemia, hypomagnesemia, hypophosphatemia, hypomagnesemia. Body as a whole: Slight increase in body temperature, fluid overload, generalized pain, back pain, fatigue, fever, moniliasis. GI: N&V;, constipation, abdominal pain, anorexia, GI hemorrhage ulcerative stomatitis. CNS: Somnolence, insomnia, dizziness, headache, paresthesia, abnormal vision, slight possibility of seizures. CV: Hypertension, atrial fibrillation, syncope, tachycardia. Respiratory: Rales, rhinitis, upper respiratory tract infection. GU: UTI. Musculoskeletal: Bone pain. At site of administration: Redness, swelling or induration, pain on palpation. Miscellaneous: Anemia, hypothyroidism, sweating.

How Supplied: Powder for injection: 30 mg, 90 mg

Dosage
?IV Infusion Moderate hypercalcemia (corrected serum calcium of about 12-13.5 mg/dL) of malignancy.
Initial therapy: 60-90 mg. The 60-mg dose is given as an initial single dose over at least 4 hr; the 90-mg dose must be given as an initial single dose over 24 hr.
Severe hypercalcemia (corrected serum calcium greater than 13.5 mg/dL) of malignancy.
Initial therapy: 90 mg as a single initial dose given over 24 hr. If retreatment is necessary, use the same dose as for initial therapy; at least 7 days should elapse before retreatment.
Moderate to severe Paget's disease.
30 mg/day given as a 4-hr infusion on 3 consecutive days (total dose: 90 mg). If retreatment is necessary, the same dosage schedule is used.
Osteolytic bone lesions of multiple myeloma.
90 mg given as a 4-hr infusion every month. Those with marked Bence-Jones proteinuria and dehydration should receive adequate hydration before infusion of pamidronate.
Osteolytic bone metastases.
90 mg given as a 2-hr infusion q 3 to 4 weeks.