Pamidronate
Synonyms :
Aminohydroxypropylidene Diphosphonate, Disodium Pamidronate
Mechanism :
Lowers serum calcium concentration by binding to the bone and inhibiting osteoclast mediated calcium resorption, it has no effect on renal tubular calcium handling.
Indication :
- Hypercalcemia
- Osteogenesis imperfecta
- Steroid induced Osteoporosis
- Idiopathic Juvenile Osteoporosis
- Paget’s disease
Contraindications :
Pregnancy
Severe renal impairment
Hypersensitivity to pamidronate
Dosing :
Hypercalcemia:
0.5 to 1 mg/kg slow IV infusion over 24 hours one time. A second dose, identical to the first one is given if significant hypercalcemia persists or recurs. A minimum of 7 days should elapse between doses.
Osteogenesis Imperfecta:
14 days-23 months:
0.5 mg/kg IV once a day x 3 days every 2 months.
For first cycle on Day 1:
0.25 mg/kg IV.
2-3 years:
0.75 mg/kg IV once a day x 3 days every 3 months.
For first cycle on Day 1:
0.38 mg/kg IV.
4 years and older:
1 mg/kg IV once a day for 3 days every 4 months.
For first cycle on Day 1:
0.5 mg/kg IV. Maximum dose: 90 mg/dose, 9 mg/kg total annual dose. Give for 1-4 years.
Osteopenia and Osteoporosis:
3 years and older:
0.4-1 mg/kg IV once a day x 3 days every 3-6 months for 1-4 years. Maximum dose: 90 mg/dose.
Adverse Effect :
Common: Hypocalcemia, hypomagnesemia, hypophosphatemia, hypokalemia. anemia, hypertension, fever, abdominal cramps, bone pain, nausea/vomiting, injection site reactions and cough.
Rare: Osteonecrosis of the jaw, reactivation of herpes zoster and simplex, rash and allergies, renal disorders, hematuria, dizziness, paresthesia, neutropenia, thrombocytopenia, visual disturbance, seizures, uveitis, scleritis.
Interaction :
Contraindicated:
Cidofovir, streptozocin.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Serum calcium >4.0, give 60 mg. Serum calcium <4.0, give 30 mg |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Unknown dialysability. Dose as in GFR<10 mL/min |
| HD | Dialysed. Dose as in GFR<10 mL/ min |
| HDF/High flux | Dialysed. Dose as in GFR<10 mL/ min |
| CAV/VVHD | Unknown dialysability. Dose as in normal renal function |
Hepatic Dose :
No dose adjustments in mild to moderate impairment. Dose adjustment in severe impairment not studied.