Osteoporosis is a chronic condition that causes bone loss, weakens bone density, and increases the risk of bone fractures. Fortunately, today’s medical treatments offer effective ways to manage this disease. Two leading options—Reclast and Prolia—are widely used to treat osteoporosis and help protect long-term bone health. While both therapies reduce bone breakdown, they work differently and offer unique benefits.
At The Infusion Center at Denver Arthritis Clinic, we administer both Reclast and Prolia and help patients choose the right therapy based on their medical history, lifestyle, and health goals.
What Is Reclast?
Reclast (zoledronic acid) is a type of bisphosphonate used to treat osteoporosis in both men and women who are at high risk for bone fractures. It works by attaching to bone surfaces and slowing the activity of osteoclasts—cells responsible for bone resorption.
By reducing the breakdown of bone tissue, Reclast helps the body retain and rebuild bone mass, particularly in areas like the spine and hips, where fractures are most common.
How Reclast Works to Strengthen Bones
In healthy bones, there’s a natural balance between bone breakdown and new bone formation. In osteoporosis, that balance is disrupted—leading to gradual bone loss and reduced strength.
Reclast helps restore this balance by:
- Inhibiting overactive bone turnover
- Preserving bone mineral density
- Supporting long-term bone strength and stability
- Reducing the risk of fractures, especially in postmenopausal women
Reclast Dosing and Convenience
One of Reclast’s biggest advantages is its low-frequency dosing and simplicity.
- Administered once yearly via a 15-minute IV infusion
- Ideal for patients who prefer fewer treatment appointments
- Works continuously once infused, staying active in the bone for a prolonged period
Consideration: Because it remains in the bone long-term, side effects though uncommon, may take time to resolve.
What Is Prolia?
Prolia (denosumab) is a monoclonal antibody that is also approved to treat osteoporosis in patients at high risk of fracture. Unlike Reclast, Prolia is not a bisphosphonate.
It targets a protein called RANKL, which plays a key role in the formation and function of osteoclasts, the cells that break down bone.
How Prolia Works to Strengthen Bones
Prolia reduces bone resorption by blocking the signals that stimulate osteoclast formation. This helps:
- Prevent ongoing bone loss
- Increase bone mass over time
- Improve overall bone structure and strength
- Provide a non-bisphosphonate alternative for patients who need a different approach
It is particularly effective for patients who haven’t responded well to other osteoporosis treatments or who have chronic kidney disease.
Prolia Dosing and Convenience
Prolia is known for its simple, twice-yearly dosing:
- Administered every six months as a subcutaneous injection
- Quick and minimally invasive
- Can be administered in a clinic setting with no recovery time needed
Consideration: Prolia's effects wear off quickly if a dose is missed, which can lead to rapid bone loss and increased fracture risk. Consistent follow-up is essential.
Key Differences Between Reclast and Prolia
Though both Reclast and Prolia are effective osteoporosis treatments, there are important differences in how they work, how they’re administered, and who they’re best suited for.
Reclast is a bisphosphonate that remains in the bone long after it is infused. Its once-yearly IV infusion schedule is ideal for patients who want minimal treatment visits. Reclast is often recommended for patients with normal kidney function and those who prefer a long-acting solution. However, its retention in the bone also means that side effects may persist longer.
Prolia, on the other hand, is not stored in bone tissue. Its twice-yearly injection provides a balance between long-term coverage and flexibility. Because it is metabolized differently, Prolia is frequently used in patients with chronic kidney disease or who have not tolerated bisphosphonates. However, consistent dosing is critical, as skipping or delaying doses can lead to rapid bone loss and fracture risk.
Common Side Effects and Considerations
Both medications are well-studied and generally well-tolerated, but they carry some risks that should be considered when choosing between Reclast or Prolia.
Side Effects of Reclast
- Flu-like symptoms such as fever, chills, and muscle pain after the first infusion
- Joint pain, bone pain, or dull aching pain
- Rare but serious risks include severe kidney problems, low calcium levels, osteonecrosis of the jaw, or atypical thigh fractures
- Not ideal for patients with impaired kidney function or dehydration
Side Effects of Prolia
- Joint or muscle pain, rash, and injection site irritation
- Risk of serious infections due to changes in immune function
- Hypocalcemia, especially in patients with low vitamin D or calcium levels
- Sudden bone breakdown or vertebral fractures if injections are missed
- Rare cases of jawbone issues similar to those with bisphosphonates
Good oral hygiene, regular bloodwork, and proper calcium and vitamin D supplementation are important for both medications. Your provider will assess your bone density, medical history, and risk factors to help you avoid complications and choose the safest option.
Which One Is Right for You?
Choosing between Reclast vs. Prolia depends on your health history, risk factors, and personal preferences. You may benefit more from Reclast if:
- You prefer a once-a-year treatment
- You do not have kidney issues
- You want a long-acting medication with less frequent visits
Prolia may be better for you if:
- You have chronic kidney disease
- You’ve had side effects with bisphosphonates
- You can commit to twice-a-year injections with close follow-up
Some patients also consider alternatives to Prolia if long-term adherence is a concern or if bone turnover rebound becomes an issue.
If you're unsure, our infusion specialists at The Infusion Center at Denver Arthritis Clinic are here to walk you through the options and help you start the right osteoporosis treatment plan for your needs.
Find the Right Osteoporosis Infusion Therapy at Denver Arthritis Clinic
Whether you’re exploring Reclast or Prolia, both therapies offer powerful tools to slow bone loss, rebuild strength, and reduce the risk of bone fractures. With proper guidance and monitoring, either treatment can help you take control of your bone health.
Call The Infusion Center at Denver Arthritis Clinic at 303.394.2828 or refer a patient online to learn more about our expert-led osteoporosis infusion services.
