Scopolamine Transdermal Patches for Motion Sickness: Prescribing Information
Apply one scopolamine 1.5 mg transdermal patch to the hairless area behind one ear at least 4-6 hours before travel, with each patch providing protection for up to 3 days. 1
Dosage and Administration
Standard Dosing
- Single patch application: One transdermal system delivering 1 mg of scopolamine over 3 days 1
- Timing: Apply at least 4 hours before antiemetic effect is required, though 6-8 hours is optimal for maximum protection 1, 2
- For faster onset: Consider combining patch application 1 hour before travel with oral scopolamine 0.3-0.6 mg 2
- Duration: Each patch remains effective for 72 hours 1, 2
- Extended use: After 3 days, remove the first patch and apply a new one behind the opposite ear 1
Application Technique
- Location: Apply to hairless postauricular area (behind one ear) on clean, dry skin 1
- Critical safety step: Wash hands thoroughly with soap and water immediately after application to prevent accidental eye contamination 1
- Single patch only: Never wear more than one patch at a time 1
- Do not cut: The patch must remain intact 1
- If displaced: Discard and apply a new patch behind the other ear 1
Mechanism and Efficacy
How It Works
- Anticholinergic action: Blocks acetylcholine receptors in the CNS, reducing neural mismatch that causes motion sickness 3
- Delivery system: Contains 1.5 mg reservoir with 140 mcg priming dose in adhesive layer, releasing approximately 5 mcg/hour 2
- Plasma levels: Protective concentration (50 pg/mL) reached after 6 hours; steady state (100 pg/mL) achieved at 8-12 hours 2
Effectiveness
- Superior efficacy: Reduces motion sickness incidence and severity by 60-80% compared to placebo 2
- Comparative effectiveness: More effective than oral meclizine or cinnarizine, similar to oral scopolamine 0.6 mg or promethazine plus ephedrine 2
- Peak protection: Most effective 8-12 hours after application 2
Contraindications
Absolute Contraindications
- Angle-closure glaucoma: Mydriatic effect can precipitate acute angle-closure glaucoma 1
- Hypersensitivity: Known allergy to scopolamine, belladonna alkaloids, or any patch component 1
Important Warnings
- Open-angle glaucoma: Monitor intraocular pressure and adjust glaucoma therapy during use 1
- Acute glaucoma symptoms: Instruct patients to remove patch immediately if experiencing eye pain, blurred vision, visual halos, red eyes, or corneal edema 1
Adverse Effects
Common Side Effects (Frequency)
- Dry mouth: Occurs in 50-60% of patients 2
- Drowsiness: Up to 20% of users 2
- Visual disturbances: Blurred vision due to reduced accommodation, particularly problematic in hypermetropic individuals 4
- Contact dermatitis: Allergic reactions in approximately 10% 2
Autonomic Effects
- Reduced salivation: Most common effect, can reduce salivary flow by 50-100% 5
- Bradycardia: Cardiovascular effects possible 4
- Urinary retention: Difficulty urinating reported occasionally 2
Central Nervous System Effects
- Memory impairment: Reduced memory for new information, particularly with prolonged or repeated use 4, 2
- Impaired attention: Decreased alertness and attention span 4
- Toxic psychosis: Rare but serious, especially in elderly and pediatric patients 6
- Delayed onset: CNS symptoms may appear hours after application due to delayed absorption 6
Special Populations and Precautions
High-Risk Groups
- Elderly patients: Higher risk for anticholinergic side effects including confusion, falls, and cognitive impairment 3, 6
- Pediatric patients: Increased risk of toxic psychosis 6
- Patients with psychiatric disease: Pre-existing mental health conditions increase risk of adverse CNS effects 6
Drug Interactions
- Anticholinergic medications: Concurrent use increases risk of adverse effects 6
- CYP3A substrates: Grapefruit juice can increase scopolamine bioavailability by 42% and prolong absorption 7
Pregnancy and Lactation
- Pregnancy: Crosses placenta; use only under close observation 7
- Breastfeeding: Passes into breast milk; consider interrupting breastfeeding or selecting alternative medication 3
Critical Safety Considerations
Hand Hygiene is Essential
- Finger-to-eye contamination: Major cause of ocular complications including mydriasis and cycloplegia 2
- After application: Wash hands thoroughly with soap and water 1
- After removal: Wash both hands and application site with soap and water 1
Disposal
- Proper disposal: Fold used patch in half (sticky sides together) and discard in household trash away from children and pets 1
Monitoring Requirements
- Response variability: 20-30% of patients fail to attain protective plasma concentrations, explaining some treatment failures 2
- Interindividual variation: Plasma concentrations range widely (11-240 pg/mL at peak) 7
- Performance effects: Short-term use generally does not affect performance, but prolonged use may impair memory storage 2
Common Pitfalls to Avoid
- Insufficient lead time: Applying patch less than 4 hours before travel reduces effectiveness 1
- Eye contamination: Failure to wash hands after application is the most common cause of visual complications 2
- Long-term use concerns: Vestibular suppressants should not be used for extended periods as they interfere with central vestibular compensation 8
- Delayed diagnosis of toxicity: Occult patch location and delayed symptom onset can delay recognition of scopolamine toxicity 6
- Multiple patches: Never use more than one patch simultaneously 1
Alternative Considerations
When Scopolamine is Contraindicated
- Meclizine: 12.5-25 mg three times daily for patients unable to use scopolamine 3
- Promethazine: 12.5-25 mg for severe cases requiring rapid onset, though more side effects including sedation and extrapyramidal symptoms 3
Combination Therapy
- Severe symptoms: Scopolamine patch plus meclizine provides complementary mechanisms when severe symptoms require combination therapy 3