What Is Zoledronic Acid (Zometa<sup>®</sup>)?
Zometa® (zoledronic acid) is a bisphosphonate medication that is indicated for individuals with bone metastases from tumors (cancer that has spread to the bones). Zoledronic acid can be used with other cancer medications, such as chemotherapy. Zoledronic acid is also indicated for the treatment of hypercalcemia of malignancy, otherwise known as excess calcium in the body as a result of cancer that has spread to the bones. In prostate cancer, zoledronic acid can be used after an individual’s cancer has progressed after exposure to at least one hormone therapy. When used to treat cancer that has spread to the bones, zoledronic acid is given as an intervenous (IV) infusion, typically once every 3-4 weeks. Zoledronic acid is often co-administered with oral calcium and vitamin D supplements.
Individuals taking zoledronic acid should be monitored for dehydration, changes in kidney function, changes to the jaw bone, extreme joint, muscle or bone pain, hypocalcemia (too little calcium in the blood), and femoral bone fractures.1
How does zoledronic acid work?
Zoledronic acid's active ingredient is a bisphosphonate that slows down the bone destruction process, also called bone resorption. Our bodies are continuously building and destroying our bones in a balanced process. Cells in our body called osteoclasts regularly break down bone to release minerals, like calcium into our blood stream. Our body also builds bone using cells called osteoblasts, and takes these nutrients out of the blood and puts them back into our bones when needed. This process is critical to our skeletal stability and maintaining our nutrient balance.
When cancer metastasizes, it can destroy bones, and add to the normal, healthy bone destruction process. At this point, bone destruction can outweigh bone growth. When bones are broken down too quickly, excess calcium is released into the blood and our bones get weaker. This can lead to hypercalcemia, or too much calcium in the blood, as well as to bone pain and fractures. By slowing down the bone destruction process, the bone building process can catch up. When our body builds bone, it utilizes calcium in the blood stream, keeping our nutrients in balance, as well as increases our skeletal stability. This can help reduce bone pain and decrease the risk of fractures. Zoledronic acid also helps reduce hypercalcemia and its symptoms, including nausea and vomiting, loss of appetite, headaches, and kidney stones.1
What are the possible side effects of zoledronic acid?
Multiple clinical trials evaluated the safety and efficacy of zoledronic acid across many different conditions. The most common side effects of zoledronic acid include nausea, fatigue, anemia (low iron in the blood), constipation, vomiting, fever, bone pain, and problems breathing. This is not an exhaustive list of all potential side effects of zoledronic acid. Talk to your healthcare provider or pharmacist for further information.1
Things to note about zoledronic acid
Several serious side effects can accompany zoledronic acid including potentially developing severe musculoskeletal pain, femoral bone fractures, or destruction of the jaw. It’s important to take good care of your teeth and visit your dentist prior to starting zoledronic acid, as well as let them know that you will be taking the medication. Alert your doctor immediately if you notice any of the following symptoms:
- Severe bone, joint, or muscle pain
- Loosening of a tooth
- Jaw pain or swelling
- Non-healing sores in the mouth or around the jaw
- Hip, thigh, or groin pain
Additionally, there is a risk of developing changes in kidney function while on zoledronic acid, as the medication is excreted by the kidneys. Your doctor will monitor your kidney function using blood tests while on zoledronic acid. Additionally, there is a risk of developing severe breathing problems while on zoledronic acid when an individual has asthma and is aspirin-sensitive. Alert your provider immediately if you are having trouble breathing, especially if you have a history of asthma or aspirin sensitivity.
Before starting zoledronic acid talk to your provider if you:
- Have any problems with your kidneys
- Have had any major dental conditions or have a major dental procedure scheduled
- Are aspirin-sensitive
- Are taking any other bisphosphonate medications including Reclast
- Are allergic to zoledronic acid or any of its ingredients, or have any other allergies
- Have any other medical conditions
- Are currently taking any other medications (prescription and over-the-counter), vitamins, or herbal supplements
You should also contact your provider if you notice any signs of an allergic reaction to the medication, including chest pain, fever, flu-like symptoms, or difficulty breathing. It is also important to consult the prescribing information for any other medications taken with zoledronic acid, including chemotherapy medications.1
Receiving zoledronic acid
Zoledronic acid is administered via an intravenous (IV) infusion, typically once every 3-4 weeks. The infusion typically takes at least 15 minutes to administer. Your provider will determine the appropriate dosage and administration schedule for you. They will also determine the appropriate dosage and administration schedule of any other medications taken with zoledronic acid, such as chemotherapies or calcium or vitamin D supplements. It is important to follow your provided schedule exactly as instructed, and not to stop taking any accompanying medications on your own. The dose of your zoledronic acid can be adjusted as needed by your doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their zoledronic acid regimen.1
These are not all the possible side effects of Zoledronic. Patients should talk to their doctor about what to expect with treatment with Zoledronic.