Bisphosphonates Print Page

What are bisphosphonates?

  • Bisphosphonates are a group of drugs that help slow bone loss. They help to keep your bones to strong and prevent them from thinning (osteoporosis).
  • Using them long-term can decrease your risk of having a broken hip or a spine fracture.

What is the typical dose?

  • The dose depends on which bisphosphonate you take:
  • Alendronate (Fosamax®)
    • 70mg once WEEKLY in the morning, on an empty stomach with a full glass of plain water.
    • Do not take with other food, medications, calcium or dairy products.
    • Stay upright for 30 minutes after dose.
  • Risedronate (Actonel®)
    • 35mg once WEEKLY, on an empty stomach with a full glass of plain water OR
    • 150mg once MONTHLY, on an empty stomach with a full glass of plain water.
    • Do not take with other food, medications, calcium or dairy products.
    • Stay upright for 30 minutes after dose.
  • Zoledronic Acid (Aclasta®) – 5mg once YEARLY by injection over 15 minutes
    • Drink at least 2 glasses of water before and after the treatment.

How do bisphosphonates work?

  • In osteoporosis, your body removes more bone than it replaces.  Bisphosphonates help correct this by slowing down the body’s rate of bone removal. Your bone thickness is measured by a test (bone mineral density) and this is one way we check to see if the bisphosphonate is working for you. The other is determining if you’ve had a fracture.

What are the possible side effects of bisphosphonates?

  • Common:
    • Stomach pain, heartburn, nausea, pain in bones, muscles
      • Get better with time.
      • If you have a history of esophagus problems or kidney problems, inform your doctor/pharmacist before starting the medication.
      • Talk to your doctor or pharmacist if it is severe.
  • Less common:
    • Low calcium levels (numbness, tingling, muscle spasms)
      • Discuss your calcium intake with your doctor, pharmacist, or dietitian. They can help you manage this.
  • Rare:
    • Wounds in your jaw from limited blood supply
      • Talk to your dentist before having dental work done.
      • Tell your doctor if you have persistent pain in your mouth or jaw.
    • Unusual break in your thigh bone
      • Talk to your doctor if you have new or unusual pain in your hip or thigh.
  • Side effects with zoledronic acid infusion
    • Flu like symptoms during and after the dose infusion (fever, fatigue, chills, feeling unwell)

Are there medications I should avoid when taking bisphosphonates?

  • Avoid supplements with calcium, magnesium or iron within 2 hours of taking the medication, as it may decrease absorption.

What do I do if I miss a dose?

  • For weekly dosing, take 1 tablet on the day you first remember having missed your dose. Then resume your normal schedule on your regular day of the week. Do not take 2 doses on 1 day.
  • For monthly dosing, if the next month’s dose is MORE than 7 days away, take the missed dose on the morning you remember.  Otherwise, wait until the next scheduled dose.

How long will I have to be on bisphosphonates?

  • Each patient is different. It depends on your risk for having a fracture over the next 10 years. Talk to your doctor or pharmacist before deciding to stop your medication.