Pamidronate

What is Pamidronate ?

Pamidronate (brand name Aredia®) is a injectable medication that lowers blood calcium levels related to some types of cancer by slowing down the release of calcium from the bones. This lowers the risk of fractures and reduces bone pain.  It is part of a class of drugs called bisphosphonates.

Why is it prescribed?

Pamidronate is prescribed for the treatment of high calcium levels due to cancer, and the damage to bones caused by cancers such as breast cancer and bone marrow cancer. It is also used to treat Paget’s disease of the bone, which is characterized by abnormal bone destruction followed by abnormal bone formation, resulting in deformity, fractures, pain and other symptoms.

What is the dosage?

Pamidronate is an injectable medication, and is administered intravenously. The medication is injected slowly over 2 to 24 hours, depending on the patient’s condition. Frequency of dosage may range from one large dose given on a one-time basis (for high blood calcium), or over 3 days in a row (Paget’s disease). For cancer-related symptoms, it may be repeated every 3 or 4 weeks. The usual maximum dosage for a single dose is 90 mg.

Contraindications

Do not use Pamidronate if you have previously had an allergic reaction to it or to other related drugs, such as zoledronic acid (Reclast® and Zometa®), alendronate (Fosamax®) and ibandronate (Boniva®), among others.

Also be sure to let your doctor know of any other allergies you may have, including allergies to foods, medications, animals, or dyes. Do not use Pamidronate if you are pregnant.

You should also talk to your physician about any herbal supplements you may be taking, and let him or her know if you have had any of the following:

• Kidney disease
• Thyroid surgery
• Low levels of red blood cells (anemia)
• Low levels of platelets
• Pre-existing dental problems, recent dental surgery
• Dehydration
• Heart failure

Be sure to drink plenty of fluids while being treated with Pamidronate. Your doctor will need to do periodic blood tests to make sure the drug is working and is not harming the kidneys.

In rare cases, osteonecrosis of the jaw (where the jaw loses bone mass, causing pain, swelling and other symptoms) may occur as a result of using this drug, particularly among cancer patients undergoing chemotherapy and those suffering from anemia and clotting disorders.

Interactions

Pamidronate may interact with the following drugs. Please let your physician know if you are taking any of these drugs before starting Pamidronate.

• Lithium
• Other bisphosphonates
• Methotrexate (Rhematrex®, Trexall®)
• Medications to prevent organ transplant rejection, such as cyclosporine
• Antiviral medications such as adefovir (Hepsera®) and others
• Any pain relievers and arthritis medications such as aspirin, acetaminophen (Tylenol®), ibuprofen (Advil®, Motrin®), naproxen (Aleve®, Naprosyn®), indomethacin (Indocin®), diclophenac (Voltaren®), etodolac (Lodine®), etc.
• Medications to treat ulcerative colitis, such as sulfasalazine (Azulfidine®)
• IV antibiotics, including vancomycin, bacitracin, gentamicin, streptomycin and others
• Cancer medications/chemotherapy agents

This is not a complete list; be sure your doctor is aware of all medications you are taking.

Side Effects

The following side effects are most common with this drug. Call your doctor if they become severe or persistent.

• Low fever
• Pain or swelling near the IV site
• Stomach pain
• Loss of appetite
• Nausea or vomiting
• Constipation
• Diarrhea
• Drowsiness
• Trouble sleeping

Call your doctor right away if you have any of the following serious side effects.

• Symptoms of allergic reaction such as swelling of the tongue, throat, lips or face; rash or hives, itching, trouble breathing.
• High fever
• Jaw pain
• Sores in jaw or mouth
• Joint or muscle pain (severe)
• Muscle weakness/jerky muscle movements/spasms
• Tingling or numbness around mouth
• Urinating less frequently or in smaller quantity; not urinating at all
• Increased urination
• Increased thirst
• Pain when urinating
• Very rapid weight gain/swelling
• Changes in vision or pain/redness in eyes, sensitivity to light
• Shortness of breath/light headedness
• Pale skin
• Rapid or uneven heart rate
• Trouble concentrating/confusion
• Seizures

Because this drug can cause people to be dizzy or drowsy, be sure you are not suffering from those side effects before driving or using heavy machinery or performing any dangerous tasks. Also limit your consumption of alcohol, as it can exacerbate these effects.

References:

http://www.medicinenet.com/pamidronate-injection/article.htm

http://www.drugs.com/mtm/pamidronate.html

This site will be up and running soon with information on Pamidronate