Reclast vs. Prolia: Similarities and Differences
Medically reviewed by Femi Aremu, PharmD
If you have osteoporosis, your healthcare provider may prescribe Reclast (zoledronic acid) or Prolia (denosumab).
Both medications are approved by the Food and Drug Administration (FDA) to treat osteoporosis. Reclast is also approved to prevent osteoporosis and treat Paget's disease.
Reclast and Prolia are both injectable medications that a healthcare provider must give. Although the two drugs are similar in form and use, they possess notable differences.
Mainly, Reclast and Prolia belong to different drug classes. Reclast is a bisphosphonate, and Prolia is a monoclonal antibody.
Reclast and Prolia injections also differ in their routes of administration and dosing frequency.
This article will explain some similarities and differences between Reclast and Prolia, including uses, side effects, interactions, and how each drug works.
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Bisphosphonates for Bone Health
Bisphosphonates are prescription medications used to help reduce bone loss in people with osteoporosis or certain other conditions that affect bone health.
Osteoporosis is when your bones become thin and weak and are more likely to break.
Several factors, including the following, may cause it:
Decreased estrogen level due to menopause
Long-term corticosteroid treatment
Taking certain medications, including some hormone treatments for breast or prostate cancer
Low body weight
Certain health conditions, such as Paget's disease
What Is Paget's Disease?
Paget's disease is a bone disease in which bones grow larger and weaker than usual.
Your body constantly replaces old bone cells with new ones.
With Paget's disease, old bone cells are removed faster than new cells are formed. As the condition progresses, new bone cells are made faster than the old ones are removed.
This leads to more extensive, softer, and weaker bones. People with Paget's disease have a higher risk of bone fractures.
The bones most commonly affected by Paget's disease include the:
Leg bones
Pelvis
Spine
Skull
Common Treatments for Bone Diseases
Common treatments for bone diseases such as osteoporosis or Paget's disease include:
Bisphosphonates, such as Reclast (zoledronic acid), Actonel (risedronate), and Binosto (alendronate)
Hormone therapy, such as Evista (raloxifene) and Miacalcin (calcitonin)
Biologics, such as Evenity (romosozumab) and Prolia (denosumab)
Relevant Statistics
Osteoporosis affects about 10 million people in the United States.
Another 44 million have an increased risk of developing osteoporosis. The condition is more common in females than in males.
About 50% of females and 25% of males will have a bone fracture in their lifetime due to osteoporosis.
What Is Reclast?
Reclast is a bisphosphonate approved by the FDA for the following uses in adults (people 18 years and older):
Treat or prevent osteoporosis in females who have gone through menopause
Increase bone mass in males with osteoporosis
Treat or prevent osteoporosis in males and females who will be taking corticosteroids long-term (at least one year)
Treat Paget's disease
Reclast comes as an injection given as an intravenous (IV, within a vein) infusion into your vein.
Generic Alternative
Reclast is also available in a generic version called zoledronic acid.
Generic Reclast also comes as an injection given as an IV infusion.
How It Works
Reclast works directly on the bones. It blocks the action of a protein that helps break down and remove bone cells.
By doing so, Reclast prevents bones from breaking down and becoming weak.
Reclast attaches firmly to bone cells. Because of this, its effects last longer than many other bisphosphonates.
Off-Label Uses
Sometimes, healthcare providers may prescribe medications to treat conditions or at different dosages than what the drug was initially approved for. This is called an off-label use.
Reclast is sometimes used off-label to help prevent bone loss in people taking specific treatments for breast cancer.
What Is Prolia?
Prolia is a monoclonal antibody approved by the FDA to treat osteoporosis in:
Adult females who have gone through menopause who have a high risk for bone fractures or cannot take other osteoporosis treatments or have taken them, and they did not work
Adults who will be taking corticosteroids for at least six months and have a high risk for bone fractures
Prolia is also FDA-approved to help increase bone mass in:
Adult males with osteoporosis who have a high risk for bone fractures
Adults receiving specific treatments for breast or prostate cancer
Prolia comes in a prefilled syringe that your healthcare provider will inject under your skin.
However, instead of receiving the medication as an injection into your vein, you'll receive Prolia as a subcutaneous injection (under your skin).
Generics vs. Biosimilars
Prolia is a biologic, meaning it's made from living cells.
Because of this, it's not possible to make an exact copy of the drug as is done with generic medications. Some biologics have biosimilar versions, however.
These versions are similar to the reference product but not exactly alike. Prolia is not available as a biosimilar.
How It Works
Monoclonal antibodies, such as Prolia, work differently than bisphosphonates and other osteoporosis treatments.
Prolia prevents your body from making osteoclasts, the cells that break down and remove bone cells.
Blocking osteoclasts from removing bone cells allows bones to grow thicker and more robust.
Off-Label Uses
Prolia may sometimes be used off-label to treat other bone diseases, such as:
Paget's disease
Hajdu-Cheney syndrome (HCS), a hereditary condition that causes decreased bone production
Some healthcare providers may also prescribe Prolia off-label to treat rheumatoid arthritis (RA).
Dosing Guidelines
The following are recommended dosages for Reclast and Prolia:
| Reclast: | Prolia: |
Osteoporosis treatment: | • 5 milligrams (mg) once per year given by IV infusion | • 60 mg injected under the skin once every six months |
Increasing bone mass: | • 5 mg once per year given by IV infusion | • 60 mg injected under the skin once every six months |
Osteoporosis prevention in females after menopause: | • 5 mg once every two years given by IV infusion | • N/A |
Osteoporosis prevention during long-term corticosteroid treatment: | • 5 mg once per year given by IV infusion | • N/A |
How Quickly Will Each Drug Work?
The effects of Reclast and Prolia may vary based on several factors, including the severity of your condition.
Reclast
It's not clear how long it takes for Reclast to start working.
However, studies have shown that its effects can last up to three years after you stop using the medication.
Prolia
Prolia helps reduce bone loss as soon as three days after you receive your first dose.
Its full effects are typically seen after about one to three months.
Safe Use Guidelines
A healthcare provider must administer Reclast or Prolia.
Below are a few guidelines on what to expect when receiving these medications.
Receiving Reclast
Your healthcare provider will give your Reclast dose by IV infusion. For Reclast, the injection should be given for at least 15 minutes.
It's important to keep your appointment to receive your Reclast dose. If you have to miss an appointment, call your healthcare provider to reschedule.
You may eat as usual before your Reclast treatment.
On the day of your scheduled dose, drink at least two glasses of liquid, such as water, within a few hours before receiving your dose. This is to help lower your risk of having kidney problems from Reclast.
Reclast can cause low blood calcium levels. Your healthcare provider will likely check your calcium level before starting Reclast treatment. If your level is low, they'll have you take calcium and vitamin D supplements to bring your blood calcium to a healthy level before you receive Reclast.
Your healthcare provider will also recommend that you continue taking calcium and vitamin D during your Reclast treatment to help prevent your calcium level from becoming too low.
Receiving Prolia
Like Reclast, Prolia is also given by a healthcare provider. However, instead of receiving the medication as an injection into your vein, you'll receive Prolia as an injection under your skin.
Your healthcare provider may inject this in your upper arm, thigh, or abdomen.
Be sure to keep your appointments to receive your Prolia injections.
If you miss an appointment, call your healthcare provider to reschedule as soon as possible. If you reschedule, you may need to adjust future appointments to allow six months between doses.
Prolia may also cause low blood calcium level.
As with Reclast, your healthcare provider will have you take calcium and vitamin D supplements before starting Prolia if your calcium level is already low.
You'll continue taking these supplements during your treatment to help prevent low blood calcium levels from Prolia.
Potential for Interaction
If prescribed Reclast or Prolia, your healthcare will first affirm that you are not currently taking any medications that may negatively interact with Reclast or Prolia.
Drug interactions can potentially affect a medication's efficacy, safety, and long-term tolerability.
Reclast
Reclast may interact with some medications.
These include:
Certain antibiotics, such as gentamicin
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as Advil or Motrin (ibuprofen)
Keep in mind that Reclast contains the active ingredient zoledronic acid. This is the same active ingredient in Zometa, a medication for specific cancer treatments.
If you're receiving treatment with Zometa, your healthcare provider will not prescribe Reclast for you.
Prolia
There are no known interactions for Prolia. However, new interactions may be discovered as new drugs are developed.
Because of this, telling your healthcare provider all the medications and supplements you take before you start treatment with Prolia is crucial.
Also, let them know if you are starting any new medications.
When to Avoid Reclast or Prolia
It's not safe to use Reclast or Prolia in certain situations.
Avoid using Reclast:
If you have a low blood calcium level
During pregnancy
If you are breastfeeding or planning to do so
If you have moderate to severe kidney disease
If you are allergic to Reclast or any of its ingredients
Avoid using Prolia:
If you have a low blood calcium level
During pregnancy or for five months afterward
If you are breastfeeding or planning to do so
If you are allergic to Prolia or any of its ingredients
Side Effects and Precautions
As with most medications, Reclast and Prolia may cause side effects in some people.
Common Side Effects of Reclast and Prolia
Common side effects of both Reclast and Prolia include:
Common Side Effects of Reclast
Side effects that are common with Reclast but not Prolia include:
Bone pain
Flu-like symptoms, such as fever, chills, and body aches
Common Side Effects of Prolia
Side effects that are common with Prolia but not Reclast include:
High blood pressure (hypertension)
Severe Side Effects of Reclast and Prolia
Although not common, Reclast and Prolia may cause severe side effects.
These include:
Unusual thigh bone fractures
In addition, using Reclast may cause severe kidney problems.
If you already have kidney problems, check with a healthcare provider before starting Prolia treatment.
Alternative Treatment Options
If you have osteoporosis, a healthcare provider may prescribe a bisphosphonate or other treatment for you.
However, there are other things you can do to help with your treatment and prevent further bone loss.
Examples include:
Taking daily vitamin D and calcium supplements
Doing regular weight-bearing exercises, such as walking, dancing, or stair climbing
Avoiding smoking
Limiting alcohol consumption
Summary
Reclast and Prolia are both osteoporosis treatments with some similarities and differences.
Reclast is a bisphosphonate with the active ingredient zoledronic acid. Prolia is a monoclonal antibody with the active ingredient denosumab.
In addition to osteoporosis treatment, Reclast has other FDA-approved indications, including treating Paget's disease and preventing osteoporosis.
Prolia is also approved to help increase bone mass in males with osteoporosis and adults receiving specific cancer treatments.
A healthcare provider must give both drugs.
Reclast is typically administered once per year by an IV infusion. Meanwhile, once every six months, Prolia is injected under your skin.
If your healthcare provider prescribes Reclast or Prolia, they'll talk with you about preparing to receive your dose. For example, they'll likely have you take calcium and vitamin D supplements during your Reclast or Prolia treatment.
Talking with your healthcare provider about your health history before starting treatment with Reclast or Prolia is important. This information will help them decide whether either of these medications is safe for you to use.
Frequently Asked Questions
How can I safely store Reclast or Prolia?
Reclast is typically stored at the clinic or other healthcare facility where you will receive your dose.
Prolia may also be stored at a healthcare facility, or you may receive it from a specialty pharmacy.
If you receive your Prolia from a pharmacy, refrigerate the injection at 36 to 46 degrees F, away from direct light and heat. Do not freeze Prolia. You should store Prolia out of sight and out of reach of children and pets.
Are people with rheumatoid arthritis at risk for developing osteoporosis?
Yes. About 30% to 50% of people with RA develop osteoporosis.
With RA, your immune system attacks the joints in your body. Many factors can contribute to increased bone loss with RA.
These include inflammation caused by RA and long-term treatment with corticosteroids.
How often will someone meet with their healthcare provider while taking Reclast or Prolia?
Someone taking Reclast will typically meet with their healthcare provider once per year to receive their dose. For someone taking Prolia, they would meet once every six months.
Sometimes, your healthcare provider may ask you to meet more often to check your blood calcium levels or how well your kidneys work.
Read the original article on Verywell Health.
