Bisphosphonates for Osteoporosis
Bisphosphonates are a class of medication used to treat osteoporosis. They work by slowing bone breakdown, increasing bone density (thickness), and decreasing the amount of calcium released from the bones into the blood.
Bisphosphonates may also be used to treat bone loss due to other medical disorders, including Paget’s disease, multiple myeloma, and prolonged use of glucocorticoid medications (prednisone).
Oral bisphosphonates that can be taken by mouth include the following:
- Alendronate (Fosamax®)
- Ibandronate (Boniva®)
- Risedronate (Actonel®)
Zoledronic acid injection (Reclast®) is a bisphosphonate that is injected intravenously (IV).
How are bisphosphonates administered?
Oral bisphosphonates should be taken on an empty stomach and with a full glass of water first thing in the morning. It is important to remain in an upright position and refrain from eating or drinking for at least 30 minutes after taking a bisphosphonate.
Intravenous bisphosphonates, such as Reclast, are injected into a vein over at least 15 minutes. They are usually injected by a health care provider in a doctor's office, hospital, or clinic. Injections are given infrequently, from once a week to once a year. Your doctor will prescribe a specific dose and frequency of administration.
Take bisphosphonates exactly as directed. Do not take more or less of your medication or take it more often than prescribed by your doctor.
What are the possible side effects from bisphosphonates?
Side effects for oral bisphosphonates may include gastrointestinal problems such as difficulty swallowing, inflammation of the esophagus, and gastric ulcer.
Side effects for intravenous bisphosphonates may include flu-like symptoms, fever, pain in muscles or joints, and headache. These side effects can occur shortly after receiving an infusion and generally stop within two to three days.
There have also been reports of osteonecrosis of the jaw and of visual disturbances in people taking bisphosphonates. Long-term use of bisphosphonates may also increase the risk of certain types of femur fracture.
Atypical subtrochanteric femur fractures are fractures in the bone just below the hip joint. Diaphyseal femur fractures occur in the long part of the thigh bone. These fractures are very uncommon and appear to account for less than 1% of all hip and femur fractures overall. Although it is not clear if bisphosphonates are the cause, these unusual femur fractures have been predominantly reported in patients taking bisphosphonates.
Bisphosphonates may cause other serious side effects.
Reference: The National Institute of Arthritis and Musculoskeletal and Skin Diseases