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Zoledronic Acid

(zoe-leh-dron-ik as-id)

Trade/other name(s): Zometa, Reclast, zoledronate

Why would this drug be used?

Zoledronic acid is a type of drug known as a bisphosphonate. It is used to help prevent problems (such as broken bones) caused by cancer that has spread to the bones. It is also used to lower high blood calcium levels and treat very weak bones (osteoporosis).

How does this drug work?

Some cancers that start in the bones (such as multiple myeloma) or that can spread to the bones (such as breast cancer) can cause the breakdown of bone. This process can release large amounts of calcium into the blood. This condition, known as hypercalcemia, can be dangerous. Cancer in the bones can also lead to fractures and other problems.

Zoledronic acid stops bone cells called osteoclasts from breaking down the hard mineral structure of bone. This slows the growth of tumors in the bone. It also slows the release of calcium into the blood, which helps lower calcium levels in the body.

Before taking this medicine

Tell your doctor…

  • If you are allergic to anything, including medicines, dyes, additives, or foods.
  • If you have ever had kidney disease. This drug may affect the kidneys, and should be used with extreme caution in people with serious kidney problems.
  • If you have any mouth or teeth problems, or if you plan to have dental work in the near future. This drug has been linked to serious damage of the jawbone in some people, especially if they have had recent dental work (see “Precautions” below).
  • If you have any other medical conditions such as liver disease (including hepatitis), heart disease, congestive heart failure, lung disease, diabetes, gout, or infections. You may need closer monitoring of these conditions while being treated.
  • If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug may cause problems if either the male or female is taking it at the time of conception or during pregnancy. Check with your doctor about what kinds of birth control can be used with this medicine. This drug should not be used during pregnancy.
  • If you are breast-feeding. Although information about this drug is not available, many drugs pass into breast milk and may affect the baby. Talk with your doctor about the possible risks of breast-feeding while taking this drug.
  • If you think you might want to have children in the future. It is not known whether or not this drug can affect fertility. Talk with your doctor about the possible risk with this drug and the options that may preserve your ability to have children.
  • About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

Using zoledronic acid along with other drugs that can affect the kidneys could result in serious kidney problems. These drugs include amphotericin B, aminoglycosides (a type of antibiotic that is usually given in the vein, such as gentamicin, tobramycin, amikacin, streptomycin, and others), and platinum-based chemotherapy drugs (cisplatin, oxaliplatin), among others.

Zoledronic acid should also be used with caution in people getting other drugs that could lower calcium levels, including:

  • Loop diuretics (certain kinds of “water pills”) such as furosemide (Lasix), bumetanide (Bumex), or ethacrynic acid (Edecrin)
  • Aminoglycoside antibiotics (such as gentamicin, tobramycin, amikacin, streptomycin, and others)
  • Calcitonin (Fortical, Miacalcin), which can be used to treat osteoporosis (severe weak bones)

This drug can lead to osteonecrosis of the jaw (see “Precautions”). Giving this drug with drugs that interfere with blood vessel formation (anti-angiogenic drugs like bevacizumab and sunitinib, for example) may increase the risk for this problem. The risk of osteonecrosis of the jaw may also be increased if this drug is used with chemotherapy and/or steroids (such as dexamethasone, methylprednisolone, and prednisone).

Check with your doctor, nurse, or pharmacist about all of your medicines, herbs, and supplements, and whether alcohol can cause problems with this medicine.

Interactions with foods

No serious interactions with food are known at this time. Check with your doctor, nurse, or pharmacist about whether some foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Zoledronic acid is given as an injection into a vein (intravenous, or IV) over 15 minutes or more. The usual dose is 4 milligrams (mg), although the dose may need to be lower in people with kidney problems. The timing will depend on the reason you are getting the drug. When zoledronic acid is used to treat high blood calcium levels, a dose is given that can be repeated a week later. To help treat tumors in the bones, it is often given once every 3 to 4 weeks. To treat weak bones (osteoporosis), it is given once a year.

You will likely be given IV fluids and/or advised to drink plenty of fluids while getting this drug to keep you hydrated and reduce the chance of kidney damage. If you are not being given this drug to lower calcium levels, your doctor may also recommend that you take a supplement containing calcium and vitamin D each day.

Your doctor will test your blood often during your treatment, looking for possible effects of the drug on the kidneys and blood chemistry levels. Based on the test results, your doctor may need to change your treatment plan. Be sure to keep all your appointments for lab tests and doctor visits.

Your doctor may delay or even stop this drug if your kidney function tests are abnormal (see “Precautions”).


This drug can damage your kidneys. The risk of severe kidney damage is higher if you already have kidney problems. Your doctor will do blood tests before you start this drug to be sure giving you this drug is safe. These tests will be done again before each dose, as the dose of the drug may need to be lowered or the drug stopped if these tests become abnormal. The risk of kidney damage is also higher if you are dehydrated. Your doctor may give you fluids into the vein (IV) to correct dehydration before you start this drug. Your doctor may also recommend that you get plenty of fluids while getting this drug to reduce the chance of kidney damage. Tell your doctor or nurse right away if you notice blood in the urine, lowered urine output, increased thirst, nausea, or vomiting.

This drug can lower calcium levels, which can sometimes lead to low blood calcium levels (hypocalcemia). The risk of hypocalcemia is higher is this drug is given along with other drugs that can lower calcium levels. This drug should not be given to patients with low blood calcium levels. Your doctor will check your calcium level before you start on this drug, and again before each dose. He or she may advise you to take calcium and vitamin D each day to help prevent low blood calcium levels. Let your doctor know if you have symptoms of low blood calcium such as muscle spasms or cramps, muscle or joint pains, changes in sensations on the face, hands or feet, or confusion. In rare cases, severe low calcium levels can lead to serious heart rhythm problems or seizures, and have even been life threatening.

In rare cases, this drug can damage the bones in the jaw, a condition called osteonecrosis of the jaw (ONJ). Most cases have been in people who had recent dental procedures such as having a tooth pulled while taking the drug. Your doctor may recommend that you get a thorough dental exam before you start taking this drug. Talk with your dentist about the best ways to prevent problems while on this drug. While you are getting treatment, check with your doctor before having any dental work done. Tell your doctor if you notice loose teeth, swollen gums, or pain or numbness in your jaw.

Rarely, this drug can cause severe bone, joint, and/or and muscle pain in the days or even months after starting. These symptoms usually go away on their own if the drug is stopped.

Rarely, patients have breathing problems such as cough, tightness in the throat, or wheezing when getting this drug. Some have other kinds of breathing problems, such as shortness of breath or tightness in the chest. This seems to be more common in patients who also have breathing problems in reaction to aspirin. Tell your doctor right away if you develop shortness of breath or other breathing problems when you are getting this drug, as it can happen again the next time you get the drug.

Avoid pregnancy while taking this drug and for some time afterward. The drug can harm the fetus and may cause problems for the mother during delivery. The drug can stay in your body for years after you stop taking it, and may affect fetal bone formation. Talk with your doctor about this.

Possible side effects

You will probably not have most of the following side effects, but if you have any, talk to your doctor or nurse. They can help you understand the side effects and cope with them.


  • Fever (lasting a few days after the infusion)
  • Flu-like symptoms (fever, chills, flushing, bone and muscle aches) in the first 3 days after your injection, which may last a week or more
  • Pain or redness at injection site

Less common

  • Bone or joint pain
  • Muscle aches
  • Runny nose
  • Cough
  • Nausea/vomiting
  • Loss of appetite
  • Constipation
  • Diarrhea
  • Shortness of breath
  • Feeling dizzy or faint
  • Feeling tired
  • Urinary tract infection
  • Anemia (low red blood cell counts) which can cause tiredness, shortness of breath
  • Blood test results showing the drug may be affecting your kidneys (Your doctor will explain the importance of these findings, if any.)*
  • Trouble sleeping
  • Agitation


  • Low blood calcium levels*
  • Damage to bones in jaw (osteonecrosis of the jaw)*
  • Broken femur (thigh bone) after little or no injury, starting with groin or thigh pain
  • Serious allergic reactions, with symptoms like feeling lightheaded or dizzy (due to low blood pressure), fever or chills, hives, nausea, itching, headache, coughing, shortness of breath, or swelling of the face, tongue, or throat
  • Kidney failure
  • Trouble breathing, coughing, tightness in the chest*
  • Irregular heartbeat (atrial fibrillation)
  • Bone and/or joint pain severe enough to require the drug be stopped*
  • Eye irritation or redness
  • Death, due to allergic reaction, low blood calcium levels, kidney failure, or some other cause

*See “Precautions” section for more detailed information.

There are other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 2001.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.

Last Medical Review: 04/20/2012
Last Revised: 01/09/2015