Pamidronate belongs to the bisphosphonate drug class, which alters bone formation and breakdown in the body. It is often used to treat high levels of calcium in the blood caused by cancer or Paget’s disease. The drug also can delay or prevent bone damage caused by certain types of cancer, such as breast cancer and bone marrow cancer.
Bones typically are affected by cancer. Some cancers can start in the bones while other can spread to the bones from different parts of the body. Cancer can lead to damaged or broken bones that result in pain and the need for surgery or radiation. If spinal bones are affected, paralysis can occur. Pamidronate does not treat cancer, but can offset the effects it has on the bones.
Paget’s disease is a condition where the bones in the body are rapidly broken down and then abnormally reformed. It is normal for bone to be broken down and rebuilt in the body, but Paget’s disease causes abnormalities in the process that result in weakened bones. People suffering from Paget’s disease experience pain, bent bones, and broken bones. Pamidronate helps slow the bone breakdown, thereby giving the body more time to rebuild the bone normally.
Hypercalcemia of malignancy is high blood calcium caused by cancer. People suffering from the condition experience nausea, constipation, lethargy, muscle pain, headaches, and changes in heart rhythm. Pamidronate is used to treat this condition as well.
High blood-calcium levels can also occur in people with hyperparathyroidism. Pamidronate is sometimes prescribed to help treat this, too. Doctors may also prescribe it to treat osteoporosis and osteogenesis imperfect, which is a genetic bone defect.
The drug is administered through a needle placed in the vein via an intravenous (IV) infusion. Pamidronate is given slowly through the IV and can take anywhere from two to 24 hours to be given. It may be given as a single dose, repeated over three days, or given once every three to four weeks. Doctors may test a patient’s blood before administering the drug. Additional blood tests may be required during the first few weeks of treatment.
Serious side effects of Pamidronate include fever, joint or bone pain, jaw pain, difficult urination, weight gain, hallucinations, bruising, bleeding, seizures, vision changes, and uneven heart rate. Less serious side effects include heartburn, nausea, runny nose, sweating, numbness, dizziness, and headaches. Patients that experience an allergic reaction from the medication typically should seek emergency medical help immediately.