9 Reclast Side Effects You Should Know About

Osteoporosis is a condition that affects millions of people around the world. And lifestyle changes, such as eating a calcium-rich diet and doing weight-bearing exercises, aren’t always enough to prevent it. 

Thankfully, there are medications such as Reclast (zoledronic acid) that can help lower your risk of fractures. It’s part of the bisphosphonate drug class. But unlike other oral medications in this first-choice class, Reclast is an infusion given no more than once a year. And like most medications, it has some side effects that are good to be aware of while you’re receiving it.

Reclast side effects at a glance

Here’s an overview of the possible side effects you may experience after receiving an infusion of Reclast. 

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Common side effects:

• Mild to moderate joint or muscle pain

• Headache

• Nausea

• Flu-like symptoms (fever, chills, fatigue)

• Dizziness

Less common side effects:

• Infusion site reactions

• Severe muscle, bone, or joint pain

• Vomiting

• Muscle spasms

• Loss of appetite

• Diarrhea

Rare but serious side effects:

• Kidney problems

• Damage to the jawbone

• Leg fractures

Let’s take a closer look at nine possible Reclast side effects and how to manage them.

1. Fever and other flu-like symptoms

You may experience flu-like symptoms, such as a fever, muscle aches, and chills, after receiving Reclast. These symptoms usually appear within 3 days of your infusion. They should go away on their own within a few days. But sometimes it may take a week or two before you start feeling better.

Your healthcare provider may recommend acetaminophen (Tylenol) the day you receive Reclast and for 3 days afterward. Studies showed that taking acetaminophen helps lessen these symptoms. And they should be less of an issue with each dose of Reclast you receive.

If you have a high fever that doesn’t go away, let your healthcare provider know. There could be something else causing it, such as an infection.

Good to know: It’s best to avoid nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Mortin, Advil), for pain or fever unless your healthcare provider OKs it. These medications can raise your risk of kidney damage if you take them with Reclast.

2. Bone, joint, or muscle pain

Another possible Reclast side effect is pain in your bones, joints, or muscles. Most of the time, you’ll feel achy for just a few days after your infusion. But in rare cases, the pain can be severe and make it difficult to move. And it can happen at any time after receiving Reclast.

If you develop severe pain after receiving Reclast, let your healthcare provider know. They’ll likely want to make sure there isn’t something else causing it, like a bone fracture. And they can recommend a safe treatment option for you.

3. Nausea and loss of appetite

Reclast can cause nausea, and in some cases you may also lose your appetite. Generally, nausea will go away on its own. Until it does, try eating smaller meals throughout the day. Do your best to stay hydrated too, since this helps protect your kidneys.

If nausea is severe or doesn’t go away, contact your provider. They may recommend an anti-nausea medication to help you feel better.

4. Headache

Headaches are a common Reclast side effect. They’ll usually go away on their own, and hydration and breathing exercises may help.

If needed, take an OTC pain reliever such as acetaminophen. But as mentioned, avoid taking NSAIDs for your headache. They can raise your risk of kidney damage if you take them with Reclast.

5. Infusion site reactions

As mentioned, Reclast is an infusion into your vein (IV) administered by a healthcare professional. So you may experience an infusion site reaction, which means a reaction in the area where the IV is inserted.

These reactions aren’t common with Reclast. But if they happen, you may notice itching, redness, or pain where your IV line is inserted. If you develop these symptoms during your infusion, let someone in the office know right away. They’ll take appropriate action to manage the reaction.

If you’re at home and notice swelling, itching, or pain where your IV was, call your healthcare provider’s office. They can suggest the best treatment options. But if the pain and swelling are severe, or don’t go away after a few days, it could be a sign of infection. You should have it examined by your provider or an urgent care center in this case.

6. Low calcium levels

Reclast helps your bones hold on to calcium. So calcium levels in your blood may drop after the infusion. In rare cases, they could drop too low. This can cause symptoms such as muscle spasms, numbness, or even seizures if left untreated.

Your provider will likely check your calcium levels before you receive Reclast. If they’re low, you may need a calcium and vitamin D supplement to prevent this side effect from happening. Your provider will let you know if this is the case. In most cases, you’ll start taking it at least 2 weeks before your infusion. But your provider will give you specific dose and timing directions based on your needs.

7. Kidney damage

Reports of kidney damage have occurred with Reclast treatment, but this is very rare. It’s more likely if you have existing kidney damage, are dehydrated, or are taking a diuretic (water pill). And remember to avoid NSAIDs, since they can also make kidney problems more likely. 

Your ]provider will check your kidney function before each Reclast infusion to make sure they’re working properly. You won’t receive Reclast if they aren’t. You also need to be fully hydrated in order to receive Reclast. You should drink at least two full glasses of water within a few hours before your infusion appointment. The extra fluid will help flush Reclast through your body and protect your kidneys.

If you’re peeing less often than usual after receiving Reclast, let your provider know right away. They may want to check your kidney function to make sure no damage has occurred. 

8. Thigh bone fractures

Reclast can raise your risk of atypical bone fractures of the thigh bone. An atypical fracture means that it happens without a known cause, such as a fall. Instead, they develop on their own. This side effect is rare, and the benefits of Reclast outweigh this risk for most people. Researchers estimate that for every thigh bone fracture caused by Reclast, about 1,200 osteoporosis-related fractures are prevented by it.

If you notice a dull, aching feeling in your thigh or groin area at any time after receiving Reclast, be sure to let your provider know. If the pain is severe, seek emergency care right away.

9. Damage to the jawbone

Although rare, jawbone damage is a possible Reclast side effect. It’s more likely in people with cancer who are receiving Zometa — a different zoledronic acid medication that’s infused more often than Reclast.

The risk for jaw damage goes up the more times you receive Reclast. So your doses will be spaced at least one year apart and limited in total number. But keep in mind that the chance of jaw damage from Reclast is extremely rare (less than 0.15%).

Practicing good oral hygiene can help prevent jaw damage. Here are some tips:

• Brush twice a day with a fluoride toothpaste

• Floss daily

• Get regular dental check-ups

• Avoid tobacco products

It’s best to have any major dental work done before starting Reclast. And be sure to tell your dentist you take Reclast during future appointments. If you notice pain or swelling in your jaw at any time after receiving Reclast, let your dentist or provider know.

When should you contact your healthcare provider about Reclast side effects?

Most Reclast side effects happen within a few days of the infusion and go away on their own within a week or two. But if any symptoms seem severe, or you’re unsure how to manage them, your healthcare provider can help.

Report any unusual pain to your provider right away — especially if it’s in your mouth, jaw, or thigh. It could be a sign of a fracture or bone damage.

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Written by:

Emilie White, PharmD

Emilie White is a clinical pharmacist with over a decade of hospital pharmacy experience. Her professional areas of interest include critical care as well as infectious and autoimmune diseases.

Edited by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

Reviewed by:

Daphne Berryhill, RPh

Daphne Berryhill, RPh, has two decades of experience as a clinical pharmacist. She spent most of her career in the Chicago area practicing in-home infusion.

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