What Are Bisphosphonates?

Bisphosphonates are prescription drugs that improve bone density. They’re used to treat several conditions associated with bone loss, including osteoporosis, and to reduce the risk of fractures. Bisphosphonates are generally safe and well tolerated, but side effects may occur.

Read on to learn more about bisphosphonates, including how they work, the conditions they treat, common side effects, and more

What Are Bisphosphonates?

• Osteopenia (softening of the bones)
• Osteoporosis (reduced bone density and strength), including prevention and reducing the risk of fractures
• Drug-related osteoporosis, for example caused by glucocorticoids or by some cancer treatments
• Paget’s disease, a disorder that causes your bones to grow too large and weak
• Cancers that have spread to the bone
• Preventing cancers like breast cancer or myeloma from causing bone damage

Types of Bisphosphonates

Oral bisphosphonates include:

• Risedronate (Actonel or Altevia)
• Alendronate (Fosamax)
• Ibandronate (Boniva), which is also available intravenously
• Zoledronic acid (Reclast or Zometa)

• Pamidronate (Aredia)
• Ibandronate
• Zoledronic acid (Reclast/Zometa)

How Do Bisphosphonates Work?

Normally, your body breaks down bone tissue (through a process called bone resorption) to create new bone. But in some illnesses, the bone doesn’t get replaced fast enough, and more bone cells get damaged than renewed.

What Are the Possible Side Effects of Bisphosphonates?

• Bone or joint pain, or flu-like generalized pain
• Other flu-like symptoms, such as muscle cramps or aches
• Nausea, tummy pain or discomfort, constipation, or diarrhea
• Headache or dizziness
• Hypocalcemia (low levels of calcium in the blood)
• Itchy rashes

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• Conditions that affect the eyes, such as uveitis, conjunctivitis, and scleritis
• Osteonecrosis of the jaw, a condition that damages the bone cells in your jaw, causing gum and tooth problems

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• Atypical femur fractures (fractures in the thigh bone)

Are There Any Risks Related to Biphosphonates?

• Are allergic or hypersensitive to bisphosphonates
• Have taken bisphosphonates in the past and developed osteonecrosis or had femur (thigh bone) fractures as a result
• Have low levels of calcium in your bloodstream (hypocalcemia)
• Have chronic kidney disease
• Have had bariatric surgery
• Have disorders of the food pipe (esophagus), including difficulty swallowing, narrowing of the esophagus, gastroesophageal reflux disease (GERD), or Barrett’s esophagus (a complication of GERD)
• Can’t sit in an upright position for at least 30 minutes

Drug Interactions

• Calcium in any form, including calcium supplements, calcium gluconate, antacids like calcium citrate (Citrical) and calcium carbonate (Tums), or anything containing magnesium. These can block the bisphosphonates from being absorbed.

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• Diuretics or “water pills,” such as furosemide (Lasix) or ethacrynic acid (Edecrin)
• Antibiotics like amphotericin B (Amphosin and Fungizone), amikacin, kanamycin, neomycin, paromomycin, streptomycin, tobramycin, and gentamicin. These may cause kidney dysfunction or lower calcium levels.
• Aspirin and NSAIDs like ibuprofen and naproxen. These may compound the effects of bisphosphonates and damage your gastrointestinal tract.
• Antiretroviral drugs (HIV treatment)
  

The Takeaway

Bisphosphonates are used to prevent bone loss and help improve bone density in conditions like osteoporosis. They’re generally safe and effective, but side effects are always possible. Bisphosphonates may interact with other drugs not listed in this article, so make sure you discuss any medications you’re taking with your doctor before you start taking them.