Rare but Serious Ocular Side Effects with Bisphosphonates
4/8/2003
Portland, OR - Bisphosphonates are a class of drugs commonly used in the treatment of osteoporosis, which is a potential complication of spondylitis. New research suggests that these medications can cause serious ocular (eye) side effects, including the loss of vision in rare cases.
Ophthalmologists Dr. Rick Fraunfelder and his father, Dr. Frederick T. Fraunfelder, from the Casey Eye Institute (Oregon Health Services University, Portland, OR), wrote a letter to the New England Journal of Medicine. They state that currently there is no mention of the potential side effects of bisphosphonates in the Physicians' Desk Reference for Ophthalmology.
Any patient on a bisphosphonate who reports vision loss or ocular pain should be referred to an ophthalmologist, the Fraunfelders advise. Specifically, physicians caring for patients who are taking bisphosphonates should "look out for deep boring eye pain, a red eye, photophobia, and decreased vision." One possible side effect of the bisphosphonate medication is scleritis, a vision -threatening and potentially blinding condition if it goes unrecognized and untreated. "A finding of particular importance to clinicians is that no case of unilateral or bilateral scleritis that developed in a person receiving bisphosphonates resolved, regardless of therapy, until the bisphosphonate was discontinued," they explain.
Another eye condition called conjunctivitis seldom requires treatment and usually decreases in intensity during continued exposure to a bisphosphonate, but discontinuation of the bisphosphonate may be required for the ocular inflammation to resolve.
Physicians need to be aware that more than one ocular side effect can occur at the same time.
The Fraunfelders first noted the side effect in patients being treated with pamidronate disodium by I.V. infusion, making it the first report of any drug causing scleritis. They reported 18 cases of scleritis, usually occurring within six hours to two days of IV pamidronate. Six of these people had scleritis occurring after a repeat drug exposure.
To view reports of ocular side effects associated with different bisphosphonate medications, please refer to www.jointandbone.org. In summary, there have been 221 reports of ocular side effects with Pamidronate, 180 reports with Alendronate, 21 reports with Etidronate, 10 reports with Risedronate, and 6 reports with Clodronate. The Fraunfelders say that the variance in number of reports for the different drugs "probably reflects the individual popularity of each medication, as well as the timing of the FDA approval."