Bisphosphonates are medications used to treat osteoporosis, or low bone density. Examples of bisphosphonates include alendronate, risedronate and pamidronate. They are commonly used and come in both oral and intravenous forms. Though most patients tolerate these medications well, side effects have been reported, some of which are potentially serious.
Gastrointestinal Complications
Bisphosphonates can cause nausea, vomiting and upper abdominal pain after ingestion of the oral form. It's thought that these symptoms are due to mucosal irritation by the medication itself on the gastrointestinal tract. A more serious side effect is esophageal ulceration, which can cause severe pain and potential perforation of the esophagus. Patients should take the pill with a full glass of water and remain upright for 30 minutes. This allows the pill to pass through the esophagus completely into the stomach. Bauer et al studied the safety of alendronate in lower doses and found similar tolerability compared to a placebo. Thus, low-dose daily alendronate may be a better option than higher-dose weekly alendronate if you have gastrointestinal symptoms.
Renal Damage
It's unclear why bisphosphonates can damage the kidneys, but they can cause various types of renal toxicity. Reports of renal damage have been more associated with intravenous forms rather than oral forms. However, many clinical trials with the oral drugs exclude patients who have chronic kidney disease, so their effects in this population are unclear.
Musculoskeletal Pain
In 2008, the FDA announced reports of bisphosphonates possibly causing a severe pain syndrome involving bone, joints and/or muscles. This can occur from days to years while on these medications and have been described as severe. The syndrome tends to resolve within days of discontinuing the medication.
Eye Problems
The most common side effect involving the eye with bisphosphonates is noninfectious conjunctivitis, which usually resolves on its own even if the medication is continued. More serious adverse events include other inflammatory eye conditions called uveitis (inflammation of the middle layer of the eye) or scleritis (inflammation of the outer wall of the eye). Symptoms such as eye redness, irritation or pain, sensitivity to light and visual changes should prompt immediate medical attention.
Osteonecrosis of the Jaw
This is a complication in which bone is exposed in the maxillofacial region (typically within the oral cavity) without healing for a prolonged period, and can be painful. Reports of this have primarily been associated with intravenous administration of bisphosphonates, more than half occurring after oral surgery. Other risk factors include cancer, corticosteroids, chemotherapy and infections. Discuss the benefits and risks of oral surgery with your doctor and dentist if you are on a bisphosphonate.
Miscellaneous
Other complications include electrolyte abnormalities and infusion reactions with intravenous administration. Other reported side effects that are controversial as to truly being caused by bisphosphonates can be found at the FDA website.
References
- Archives of Internal Medicine; Upper gastrointenstinal tract safety profile of alendronate"; Bauer DC et al;February 2000
- U.S. Food and Drug Administration
- Hormones; Bisphosphonate-associated adverse events; Papapetrou PD; Apr-Jun 2009
Member Comments