Can scopolamine (transdermal patch) cause dizziness?

Scopolamine Transdermal Patch and Dizziness

Yes, scopolamine transdermal patches can cause dizziness as a side effect, as explicitly listed in the FDA drug label. 1

Mechanism and Side Effect Profile

Scopolamine is an anticholinergic medication that competitively inhibits muscarinic receptors for acetylcholine, acting as a nonselective muscarinic antagonist. It produces both peripheral antimuscarinic effects and central sedative, antiemetic, and amnestic effects 2. The transdermal patch contains a 1.5-mg drug reservoir and releases approximately 0.5 mg of scopolamine over a 3-day period at a rate of 5 μg/hour 2.

Common side effects of scopolamine transdermal patches include:

• Dizziness (explicitly listed in FDA labeling) 1
• Dry mouth
• Blurred vision or eye problems
• Feeling agitated or irritable
• Drowsiness
• Confusion/disorientation 1

Clinical Evidence and Warnings

The FDA drug label clearly states dizziness as a common side effect 1. Additionally, research studies have documented cases where patients experienced dizziness while using scopolamine patches:

• A 2015 case report described a 62-year-old woman who developed dizziness approximately 24-36 hours after removing a scopolamine patch that had been worn continuously for 7 days 3
• A 1985 study noted that gait disturbances and vertigo could occasionally occur after application of two scopolamine patches 4

Special Considerations

Several important considerations should be kept in mind when using scopolamine patches:

1. Onset timing: The onset of therapeutic effect takes approximately 6-8 hours after application 5, 2, which means patients may not experience immediate relief from motion sickness

2. Duration: The patch is designed to be effective for approximately 3 days 1, 2

3. Withdrawal symptoms: Patients may experience withdrawal symptoms 24 hours or more after removing the patch, which can include dizziness, nausea, vomiting, stomach cramps, sweating, confusion, muscle weakness, low heart rate, or low blood pressure 1, 3

4. Contraindications: The National Comprehensive Cancer Network recommends caution when using scopolamine patches in elderly patients, patients with glaucoma, urinary retention, prostatic hypertrophy, seizure disorders, and pregnant women 5

5. Drug interactions: Scopolamine may interact with other medications, particularly:

   • Sedatives, hypnotics, opioids, or anxiolytics
   • Antidepressants
   • Other anticholinergic medications 1

Management Recommendations

If a patient experiences dizziness while using a scopolamine patch:

1. Consider removing the patch if dizziness is severe or intolerable
2. Avoid activities requiring mental alertness such as driving or operating heavy machinery 1
3. Ensure adequate hydration
4. Monitor for other anticholinergic side effects
5. Consider alternative antiemetic medications if necessary

Prevention

To minimize the risk of dizziness:

1. Use only one patch at a time as directed 1
2. Avoid alcohol while using scopolamine patches 1
3. Be cautious with concomitant use of other medications that may cause dizziness
4. Apply the patch at least 4 hours before anticipated need for motion sickness prevention 1

In conclusion, dizziness is a recognized side effect of scopolamine transdermal patches that patients should be informed about before use. Proper application and adherence to recommended usage guidelines can help minimize this risk.