The scopolamine transdermal patch (Transderm Scop) is one of the most commonly prescribed anti-nausea medications for surgical patients, especially those with a history of motion sickness or post-operative nausea. Applied behind the ear before surgery, it delivers medication for up to 72 hours. This guide covers proper use, common side effects, and important safety information.
How the Scopolamine Patch Works
Scopolamine is an anticholinergic medication that blocks acetylcholine receptors in the vomiting center of the brain (the chemoreceptor trigger zone) and the vestibular system. By reducing signals from both pathways, it prevents the nausea and vomiting triggered by anesthesia, opioid pain medications, and surgical manipulation of the abdomen or inner ear.
The patch is applied to the hairless skin behind one ear, 4 hours before the end of surgery (your anesthesiologist typically applies it in the operating room) or the evening before surgery. It takes 4 to 8 hours to reach therapeutic drug levels, which is why advance application matters.
Each patch delivers scopolamine continuously for 72 hours (3 days). If nausea risk extends beyond 3 days (common after major abdominal or inner ear surgery), your surgeon may prescribe a second patch. Remove the old patch before applying the new one behind the opposite ear.
The patch is most effective for patients identified as high-risk for post-operative nausea and vomiting (PONV). Risk factors per the Apfel score include: female sex, history of PONV or motion sickness, nonsmoking status, and expected use of post-operative opioids. Patients with 3 or 4 of these factors have a 60% to 80% baseline PONV risk without prevention.
Common Side Effects and How to Manage Them
Dry mouth affects 30% to 65% of patients wearing the scopolamine patch (per the prescribing information). Keep water, ice chips, or sugar-free hard candy available. Dry mouth is annoying but not dangerous. It resolves within 24 hours of removing the patch.
Blurred vision or difficulty focusing, especially on close objects, occurs in approximately 10% to 20% of patients. This is caused by pupil dilation (mydriasis) from scopolamine entering the eye, usually from touching the patch and then touching your eye. Always wash hands thoroughly after handling the patch. If one pupil is dilated, it is almost always from inadvertent scopolamine transfer, not a neurological emergency.
Drowsiness and mild dizziness are common for the first 12 to 24 hours. These effects overlap with residual anesthesia and opioid side effects, making it difficult to attribute them solely to the patch. Avoid driving or operating machinery for 24 hours after patch removal (the drug continues to release from the skin even after removal).
Urinary retention (difficulty starting or completing urination) can occur, particularly in older men with enlarged prostates. If you cannot urinate within 6 to 8 hours after surgery, notify your nurse. Scopolamine is generally avoided in patients with known urinary obstruction or untreated narrow-angle glaucoma.
Proper Application and Removal
Apply the patch to clean, dry, hairless skin behind the ear. Do not apply to cuts, rashes, or irritated skin. Press firmly for 10 to 15 seconds to ensure good adhesion. If the patch falls off in the shower, dry the skin and apply a new patch behind the opposite ear.
When removing the patch, peel it off gently and fold it in half (sticky sides together) before discarding it. Wash your hands and the skin behind the ear thoroughly with soap and water. Residual drug on the skin can continue to be absorbed.
Do not cut the patch in half to reduce the dose. The patch is a controlled-release reservoir system, and cutting it destroys the release mechanism, potentially delivering the entire drug dose at once. If a lower dose is needed, your doctor should prescribe oral ondansetron (Zofran) or another alternative instead.
After removing the patch, some patients experience rebound nausea, dizziness, or headache 24 to 48 hours later. This withdrawal effect is more common after wearing the patch for the full 72 hours. Tapering by wearing the patch for shorter periods is not practical given its design. Ondansetron (Zofran) can manage rebound nausea if it occurs.
Can I shower or swim with the scopolamine patch on?
Yes, you can shower with the patch in place. The adhesive is designed to withstand brief water exposure. Pat the area dry gently after showering (do not rub). Prolonged water submersion (swimming, baths lasting over 20 minutes) may loosen the adhesive. If the patch detaches, dry the skin, and apply a new patch behind the other ear. Contact your surgeon if you need a replacement prescription.
Why is one of my pupils bigger than the other after using the scopolamine patch?
Unilateral pupil dilation (anisocoria) after scopolamine patch use is almost always caused by touching the patch or the skin behind your ear, then rubbing your eye. The scopolamine on your fingertip paralyzes the iris sphincter muscle in that eye, causing dilation that lasts 24 to 72 hours. It is not dangerous and resolves on its own. Wash your hands after touching the patch area to prevent this.
Who should not use the scopolamine patch?
The patch is contraindicated in patients with narrow-angle glaucoma (it can trigger an acute glaucoma attack), known hypersensitivity to scopolamine or belladonna alkaloids, and children under 12 years (safety not established). Use with caution in patients over 65 (increased sensitivity to anticholinergic effects), patients with urinary obstruction or enlarged prostate, patients with intestinal obstruction, and patients with myasthenia gravis.
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This guide provides general information. For instructions tailored to your specific procedure, ask your provider about QR Rx care plans.
These medication guides are for educational purposes only and do not replace medical advice. Always follow your healthcare provider's specific medication instructions.
