Reactions 1313 - 7 Aug 2010

Long-term amantadine may lead tocorneal changes

Amantadine appears to have an adverse effect oncorneal endothelial cells in a dose-dependent mannerwhen used long term, say researchers from Korea.1

Their cross-sectional study involved 169 subjects(169 eyes) receiving oral amantadine for Parkinson’sdisease, and the same number of age- and gender-matched controls.

When corneal endothelial indices were comparedbetween the amantadine-treated and control groups, theformer had significantly lower endothelial cell density,lower hexagonality and greater coefficient of variation.Longer duration of amantadine therapy, and a highercumulative dose (up to 8 years), resulted in the mostsignificant reduction in corneal endothelial cell density(p < 0.05), compared with the normal age-matchedcontrol group.

Change "does not occur quickly"A release from the American Academy of

Ophthalmology comments that this study shows thereduction in corneal endothelial cell density in responseto amantadine treatment "does not occur quickly".2 Inaddition, it revealed that two early indicators ofabnormal corneal changes in response to amantadineoccurred before endothelial cell density reduction:deformation of the normal hexagonal cell shape, and anincrease in cell size variation.

The study’s lead author Dr Won Ryang Wee says that"assuming other studies confirm these results,ophthalmologists and neurologists should considerevaluating a patient’s corneal endothelium at thebeginning of treatment with amantadine and reassess atregular intervals if the drug is used long term".1. Chang KC, et al. The Effect of Amantadine on Corneal Endothelium in Subjects

with Parkinson·s Disease. Ophthalmology 117: 1214-1219, No. 6, Jun 2010.Available from: URL: http://dx.doi.org/10.1016/j.ophtha.2009.10.039.

2. American Academy of Ophthalmology. Antidepressants Linked to CataractRisk; Parkinson’s Drug May Cause Corneal Damage. Media Release : 1 Jun2010. Available from: URL: http://www.aao.org.

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Reactions 7 Aug 2010 No. 13130114-9954/10/1313-0001/$14.95 © 2010 Adis Data Information BV. All rights reserved