Publications

Published: September 2011

Reminder: Keeping an eye on bisphosphonates

Prescriber Update 32(3): 24
September 2011

Prescribers are reminded that bisphosphonates have been associated with a number of rare but serious ocular inflammatory effects, including uveitis and scleritis.

As of 30 June 2011, CARM had received a total of 28 reports of uveitis (including iritis) associated with a variety of medicines. Of these reports over one third (8) were assessed by CARM as being causally associated with the use of bisphosphonates.

Alendronate was associated with the majority of the reports received (4); reports of uveitis have also been received in association with the use of pamidronate (3) and zoledronate (1). Due to the indications for which bisphosphonates are approved, the cases generally involved older females.

Time to onset of the reaction after bisphosphonate administration was generally short, with all cases occurring within one month of treatment initiation. The majority of cases noted that the patient had recovered or improved at the time of the report.

Uveitis is characterised by inflammation of the uvea – the pigmented, vascular inner coat of the eye consisting of the choroid, ciliary body and iris.1 Uveitis can be classified anatomically based on which part of the eye is inflammed: 2

The most common symptoms of uveitis include redness of the eye (particularly around the margin of the cornea), photophobia, eye pain (typically an ache), decreased or blurred vision, and floating spots in the visual field.

In anterior uveitis, the pupil may be smaller in size and sometimes irregular. In severe cases of anterior uveitis, a collection of creamy coloured inflammatory debris (hypopion) may be visible overlying the lower part of the iris.4 Uveitis can affect one or both eyes.2

Serious complications of uveitis include cataracts, glaucoma, retinal oedema and permanent blindness.2

In patients with suspected drug-induced uveitis the suspected medicine should be discontinued and the patient referred to an ophthalmologist for examination and treatment to control the inflammation. With prompt diagnosis and treatment, drug-induced uveitis is almost always reversible.5

Uveitis had also been linked with autoimmune diseases, systemic conditions, and infections.3

References
  1. Goldstein D., Pyatetsky D., Tessler H. 2009. Classification, symptoms and signs of uveitis. In: W Tasman, E Jaeger (eds). Duane's Ophthalmology (15th Ed). Philadelphia: Lippincott Williams & Wilkins.
  2. Kanski J. 2003. Uveitis. Clinical Ophthalmology – A Systematic Approach (5th Ed). New York: Butterworth-Heinemann.
  3. Morris A., Elder M. 2006. Uveitis, drugs, and the HLAB27 antigen. The New Zealand Medical Journal. 119(1230). http://www.nzma.org.nz/journal/119-1230/1887/
  4. Personal communication, August 2011, Opthalmologist, Wellington.
  5. Fraunfelder F., Rosenbaum J. 1997. Drug-induced uveitis – Incidence, prevention and treatment. Drug Safety. 17(3): 197-207.