Home Drug Guide Pamidronate Disodium

Drug Guide

Generic Name

Pamidronate Disodium

Brand Names Aredia

Classification

Therapeutic: Bisphosphonate, Antiresorptive Agent

Pharmacological: Pyrophosphate analog that inhibits osteoclast-mediated bone resorption

FDA Approved Indications

  • Hypercalcemia of malignancy
  • Osteolytic bone lesions of multiple myeloma and breast carcinoma

Mechanism of Action

Pamidronate binds to hydroxyapatite in bone, inhibiting osteoclast-mediated bone resorption, leading to decreased release of calcium from bones.

Dosage and Administration

Adult: IV infusion of 60-90 mg over 2-24 hours, repeated every 3-4 weeks as needed

Pediatric: Off-label; dosing varies based on condition and weight

Geriatric: Adjust based on renal function, usual dosing as adult

Renal Impairment: Dose reduction or increased interval may be necessary based on severity

Hepatic Impairment: No specific adjustment required

Pharmacokinetics

Absorption: Poor oral absorption; administered intravenously

Distribution: Binds strongly to bone tissue, minimal distribution to other tissues

Metabolism: Not metabolized; remains bound to bone

Excretion: Renal excretion of unchanged drug

Half Life: Approximately 1-2 hours in plasma; prolonged in bone, with terminal half-life of approximately 20 days due to binding to bone

Contraindications

  • Hypocalcemia
  • Allergy to bisphosphonates

Precautions

  • Renal impairment (dose adjustment required)
  • Pregnancy and lactation (category C); potential risk to fetus, use only if benefits justify risks

Adverse Reactions - Common

  • Fever, chills, flu-like syndrome (Common)
  • Injection site reactions (Common)
  • Musculoskeletal pain (Common)

Adverse Reactions - Serious

  • Osteonecrosis of the jaw (Rare but serious)
  • Renal toxicity leading to failure (Rare)
  • Hypocalcemia (Uncommon)

Drug-Drug Interactions

  • Nephrotoxic agents (e.g., aminoglycosides, NSAIDs) may increase renal toxicity

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor serum calcium, phosphate, and renal function

Diagnoses:

  • Risk for hypocalcemia
  • Impaired renal function

Implementation: Administer IV infusion over recommended time, ensure patient is well-hydrated, advise patient to report new jaw pain or signs of osteonecrosis of the jaw

Evaluation: Assess for symptom improvement, monitor laboratory parameters

Patient/Family Teaching

  • Maintain adequate calcium and vitamin D intake
  • Report any jaw pain, dental problems, or signs of hypocalcemia
  • Inform about potential flu-like symptoms after infusion

Special Considerations

Black Box Warnings:

  • Osteonecrosis of the jaw, especially in cancer patients
  • Severe renal impairment

Genetic Factors: N/A

Lab Test Interference: May cause transient hypocalcemia affecting calcium lab tests

Overdose Management

Signs/Symptoms: Hypocalcemia, hypophosphatemia, renal failure

Treatment: Discontinuation of drug, calcium and hydration therapy, renal support if needed

Storage and Handling

Storage: Store in a cool, dry place, protected from light

Stability: Stable under recommended conditions for the duration of the shelf life

This guide is for educational purposes only and is not intended for clinical use.