After 3–5 years on alendronate (Fosamax) or risedronate (Actonel), many Canadians are told to "take a drug holiday." That phrase creates more anxiety than it resolves. This page explains what a drug holiday actually is, who it's appropriate for, how long it lasts, and — critically — how it's completely different from stopping Prolia (denosumab).
A bisphosphonate drug holiday means pausing oral therapy — typically alendronate or risedronate — for 1 to 3 years after an initial treatment period. It's not quitting. It's not giving up. And it's not something every patient should do.
The rationale comes from bisphosphonate pharmacology: these drugs bind tightly to bone and slowly release over years, continuing to suppress bone breakdown long after you stop taking the pill. Alendronate has an estimated half-life in bone of approximately 10 years. This residual effect is what makes a planned break possible.
The concept was formalized in a 2021 narrative review (PMC7963175) and reinforced in subsequent Endocrine Society and Osteoporosis Canada guidance. The core principle: after 3–5 years of adequate therapy, patients at low-to-moderate fracture risk have accumulated enough bisphosphonate in their bones to maintain protection for a period without taking additional medication.
Most patients ask about stopping because they've heard about atypical femur fractures (AFF) — stress fractures of the femoral shaft that have been linked to long-term bisphosphonate use. The concern is legitimate but frequently misunderstood.
AFF risk does increase with duration of use: roughly 3–50 cases per 100,000 patient-years at 3–5 years, rising to around 100 per 100,000 at 8–10 years. Those numbers sound alarming until you compare them to the fracture risk bisphosphonates are preventing. Alendronate reduces vertebral fracture risk by approximately 47% and hip fracture risk by 51%. For most patients, stopping early because of AFF fear would result in far more fractures than it prevents.
Osteonecrosis of the jaw (ONJ) follows the same logic: real but rare (roughly 1–10 per 100,000 patient-years), and manageable with proper dental care. Your dentist should know you're on bisphosphonates before any invasive dental work — see the medications overview for more on ONJ and dental precautions.
Osteoporosis Canada and the 2025 Oxford JCEM guidance both emphasize that one size doesn't fit all. The decision depends on your total bisphosphonate exposure, current BMD, fracture history, and the specific drug you've been on.
A drug holiday is generally appropriate if:
This is just as important. A drug holiday is not appropriate for higher-risk patients, even after 5 years of treatment. Reasons to continue:
If your doctor is recommending a holiday despite any of the above, it's worth asking why — and whether a second opinion from an osteoporosis specialist makes sense. Many academic medical centres in Canada (University of Toronto, UBC, University of Alberta) have dedicated metabolic bone clinics.
Zoledronic acid (Reclast/Aclasta), given as an annual IV infusion, accumulates in bone faster and has a stronger and longer-lasting effect than oral alendronate. The drug holiday math changes accordingly.
After 3 years of annual IV zoledronic acid, many guidelines suggest the holiday can be shorter — often 2–3 years rather than 3 — before reassessment. After 6 years of IV therapy, the residual protection in high-risk patients may not be sufficient for a long break.
Your endocrinologist or rheumatologist will calculate this based on your total drug exposure, not just years of treatment.
Typical guidance:
| Drug | Typical Holiday Duration | Notes |
|---|---|---|
| Oral alendronate (Fosamax/generic) | 1–3 years | Most studied; residual effect 5–10 years post-stop |
| Oral risedronate (Actonel/generic) | 1–2 years | Shorter skeletal half-life than alendronate |
| IV zoledronic acid (Aclasta) | 2–3 years after 3 years of therapy | Shorter holiday after longer IV exposure |
These are starting points, not fixed rules. Your doctor should set the expected duration at the beginning of the holiday, not leave it open-ended.
For oral alendronate specifically, bone turnover markers may start rising within months of stopping, but actual BMD loss is typically modest over 1–2 years — often less than 2% at the hip. The skeletal reservoir of retained drug provides ongoing protection.
This is very different from what happens when you stop Prolia (denosumab). Prolia has no stored reservoir — when the drug clears the system (within months), bone turnover rebounds sharply, sometimes violently. The Prolia rebound situation is a separate medical issue with a completely different risk profile and management approach. The two situations should never be conflated.
A drug holiday without monitoring is just stopping. Appropriate follow-up:
If you're not sure when your next DEXA is scheduled, ask at your next GP appointment. In most provinces, DEXA follow-up scans during treatment or a drug holiday are covered — but the referral pathway matters. In British Columbia, for example, BC PharmaCare covers bone density testing at defined intervals under PharmaCare Plan B and G.
Keep taking them. Osteoporosis Canada recommends 1,200mg of calcium daily (combined food plus supplements) and 800–2,000 IU of vitamin D for most adults over 50. The drug holiday suspends your bisphosphonate — not the foundational nutrition your bones need. See the calcium guide and vitamin D guide for specifics.
Many patients are told "take a break" without understanding the duration, the monitoring plan, or the restart criteria. These questions help:
If you were on bisphosphonates because of glucocorticoid-induced osteoporosis, the drug holiday framework may not apply in the same way — the underlying risk driver (the steroid) is still active.
Generic alendronate 70mg (weekly) costs roughly $10–$25/month at Shoppers Drug Mart or Rexall. It's covered on most provincial drug plans — Ontario ODB, BC PharmaCare, Alberta Drug Benefit List — without special authorization for patients who meet the clinical criteria. If you're restarting after a holiday, your GP can write the prescription directly.
The affordability of generic bisphosphonates is actually a clinical asset: for most patients, cost is not a barrier to restarting therapy when the holiday ends, which removes one reason to delay.