What to do if anisocoria (unequal pupil size) occurs after applying a scopolamine (hyoscine) patch?

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Last updated: June 18, 2025View editorial policy

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From the FDA Drug Label

Inform patients that temporary dilation of the pupils and blurred vision may occur if scopolamine transdermal system comes in contact with the eyes The FDA drug label does not answer the question.

From the Research

If you notice anisocoria (unequal pupil size) after applying a scopolamine patch, remove the patch immediately and wash the affected area thoroughly with soap and water. This condition likely occurred because you touched the patch and then accidentally touched your eye, transferring the medication. Scopolamine is an anticholinergic medication that can cause pupil dilation when it comes in contact with the eye, as reported in a case study published in 2021 1. After removing the patch and washing your hands, rinse your eye with cool water for several minutes. The pupil dilation typically resolves within 24-72 hours as the medication effect wears off, as observed in a study published in 2020 2. During this time, you may experience light sensitivity and blurry vision in the affected eye, which are temporary. If symptoms persist beyond 3 days, worsen significantly, or if you develop eye pain, severe headache, or vision changes, seek immediate medical attention. To prevent this issue in the future, always wash your hands thoroughly after handling the patch and avoid touching your eyes until you've washed your hands, as recommended in a study published in 2013 3.

Some key points to consider:

  • Scopolamine patches can cause anisocoria due to accidental transfer of the medication to the eye, as reported in several case studies 2, 1, 4.
  • The condition is usually temporary and resolves on its own within 24-72 hours, as observed in a study published in 2020 2.
  • It is essential to wash your hands thoroughly after handling the patch and avoid touching your eyes until you've washed your hands to prevent this issue, as recommended in a study published in 2013 3.
  • If you experience any severe or persistent symptoms, seek immediate medical attention, as advised in a study published in 2001 4.

Overall, the management of anisocoria after scopolamine patch application involves prompt removal of the patch, washing the affected area, and monitoring for any severe or persistent symptoms, as supported by the evidence from several studies 2, 1, 3, 4.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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