How Do Calcium Metabolism Modifiers Work?

Calcium metabolism modifiers are a class of drugs used to prevent the loss of bone density to treat postmenopausal osteoporosis (a condition in which bones become thin and weak and break easily), osteoporosis in men, glucocorticoid-induced osteoporosis (a type of corticosteroid medication that may cause osteoporosis), and Paget’s disease (a condition in which bones become soft and weak and may be deformed, painful, or easily broken) and to treat high levels of calcium in the blood that may be caused by certain types of cancer.

Bone tissue undergoes constant remodeling and is kept in balance (homeostasis) by osteoblasts (cells that form a new bone) and osteoclasts (responsible for bone resorption) activity. Calcium metabolism modifiers inhibit the digestion of bone by encouraging osteoclasts to undergo apoptosis (cell death), thereby slowing down bone loss. They help reduce the incidence of fractures (hip and vertebral and nonvertebral osteoporosis-related fractures) and are also used with cancer chemotherapy to treat bone problems that may occur with multiple myeloma (cancer that begins in the plasma cells) and other types of cancer (such as breast and lung) that have spread to bones.

Calcium metabolism modifiers work in the following ways:

• Belong to a class called "bisphosphonates."
• Work by slowing down the bone loss to help maintain strong bones and reduce the risk of bone fractures.
• Increase bone density (thickness).
• In addition, they help in lowering high blood calcium levels by reducing the amount of calcium released from bones into the blood.

Calcium metabolism modifiers are used in conditions such as:

• Postmenopausal osteoporosis
• Osteoporosis in men
• Glucocorticoid-induced osteoporosis
• Hypercalcemia of malignancy 
  • Multiple myeloma (cancer that forms in a type of white blood cells called plasma cells)
  • Osteolytic bone metastases of breast cancer
  • Bone metastases from solid tumors
• Heterotopic ossification (growth of bone tissue in an area of the body other than the skeleton) in patients with:
  • Total hip replacement surgery (surgery to replace the hip joint with an artificial joint) 
  • Spinal cord injury
• Paget's disease (a condition in which bones become soft and weak and may be deformed, painful, or easily broken)

Some of the common side effects include:

• Diarrhea
• Nausea
• Vomiting
• Myalgia (muscle pain)
• Stomach upset
• Joint pain
• Weakness
• Abdominal pain
• Headache
• Constipation
• Heartburn
• Back pain
• Flatulence (gas)
• Leg cramps
• Loss of appetite
• Arthralgia (pain in one or more joints)

Other rare side effects include:

• Chest pain
• Dizziness (feeling faint, weak, or unsteady)
• Severe muscle spasms
• Numbness or heavy feeling in the jaw
• Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• Flu-like symptoms (such as fever, chills, and muscle/joint aches)
• Difficulty breathing
• Hypocalcemia (low blood calcium level)
• Insomnia (trouble falling and/or staying asleep)
• Fast/irregular/heartbeat

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of calcium metabolism modifiers include:

• Actonel
• Actonel with calcium
• Alendronate
• Aredia
• Atelvia
• Binosto
• Boniva
• Calcitonin salmon
• Didronel
• Etidronate
• Fosamax
• Fosamax plus D
• Ibandronate
• Miacalcin
• Pamidronate
• Reclast
• Risedronate
• Skelid
• Zoledronic acid
• Zometa