Scopolamine

Motion Sickness

Scopolamine is used to prevent symptoms of motion sickness, including nausea, vomiting, and dizziness. It is commonly used by individuals traveling by boat, plane, or car who are prone to these symptoms.

Post-Operative Nausea and Vomiting

Healthcare providers may prescribe scopolamine to prevent nausea and vomiting that can occur after a patient wakes up from anesthesia or following certain surgical procedures. It is typically administered before the surgery takes place to be effective during the recovery period.

Mechanism of Action

Scopolamine belongs to a class of medications known as anticholinergics. It works by interfering with the transmission of nerve impulses by blocking the action of acetylcholine, a chemical messenger in the nervous system.

Preventing Motion Sickness

Motion sickness occurs when there is a conflict between what your eyes see and what your inner ear senses regarding movement. Scopolamine helps manage this by:

• Affecting the inner ear: It acts on the vestibular system, which is responsible for balance, to reduce the signals sent to the brain during motion.
• Targeting the vomiting center: It blocks signals in the area of the brain that triggers the vomiting reflex.
• Restoring chemical balance: It helps correct the imbalance between acetylcholine and other chemicals that can occur during motion.

When used as a skin patch, the medication is absorbed slowly through the skin and into the bloodstream, providing a steady level of the drug to help prevent symptoms before they start.

Other Effects

Because it blocks acetylcholine throughout the body, scopolamine also reduces the production of bodily fluids, such as saliva and sweat. This action is sometimes used in medical settings to decrease secretions in the mouth and airways.

Common Side Effects

The most frequent side effects of scopolamine include:

• Dry mouth
• Drowsiness or sleepiness
• Blurred vision and dilated pupils
• Dizziness
• Sore or itchy eyes
• Constipation
• Dry or itchy skin at the application site

Serious Side Effects

Contact a healthcare provider immediately if you experience any of the following:

• Confusion, agitation, or hallucinations
• Extreme restlessness
• Eye pain, redness, or seeing halos around lights
• Difficulty urinating or painful urination
• Rapid or irregular heartbeat
• Severe skin rash, hives, or swelling
• Seizures

Withdrawal Symptoms

If scopolamine is used for several days and then stopped suddenly, some people may experience withdrawal symptoms. These can include dizziness, nausea, vomiting, headache, and problems with balance or coordination. These symptoms usually do not appear until 24 hours or more after removing the patch.

Central Nervous System Effects

Scopolamine may cause significant drowsiness, confusion, and disorientation. Some individuals may experience hallucinations, agitation, or memory loss. These effects are more common in the elderly. Activities requiring mental alertness, such as driving or operating machinery, should be avoided until the drug's effects are understood.

Glaucoma and Eye Pressure

This medication is contraindicated in individuals with narrow-angle glaucoma. Scopolamine can increase intraocular pressure, potentially leading to an acute glaucoma attack. If eye pain, redness, or blurred vision occurs, medical attention should be sought immediately.

Heat Sensitivity

Scopolamine can inhibit sweat gland secretion, which may impair the body's ability to regulate temperature. This increases the risk of overheating and heatstroke, particularly in hot climates or during exercise.

Gastrointestinal and Urinary Issues

Caution is necessary for those with urinary retention or bladder neck obstruction, as the medication can make urination more difficult. It should also be used with caution in individuals with gastrointestinal obstructions, such as pyloric stenosis, or decreased intestinal motility.

MRI Precautions

Transdermal patches may contain metal in the backing. To avoid the risk of skin burns, the patch must be removed before a Magnetic Resonance Imaging (MRI) procedure.

Discontinuation and Withdrawal

Abruptly stopping scopolamine after several days of use can lead to withdrawal symptoms. These may include:

• Dizziness and disturbances in equilibrium
• Nausea and vomiting
• Headache
• Low blood pressure

These symptoms typically develop 24 hours or more after the medication is discontinued.

Seizure Risk

Seizures have been reported in individuals using scopolamine. Caution is advised for those with a history of seizures or those taking other medications that lower the seizure threshold.

Pregnancy

There are no adequate and well-controlled studies regarding the use of scopolamine in pregnant women. Animal reproduction studies have not always been performed or have shown mixed results. Because human data is limited, scopolamine should be used during pregnancy only if clearly needed.

Healthcare providers exercise particular caution in patients with severe preeclampsia, as there have been reports of seizures occurring after the administration of scopolamine in these individuals. If you are pregnant or planning to become pregnant, you should discuss the potential risks and benefits with your doctor before using this medication.

Breastfeeding

It is not known with certainty whether scopolamine passes into breast milk. However, many drugs are excreted in human milk, and caution is recommended when scopolamine is administered to someone who is breastfeeding.

There is also a possibility that scopolamine, which is an anticholinergic medication, may decrease the production of breast milk. If you are nursing, consult your healthcare provider to discuss whether you should continue breastfeeding while using this medication or if an alternative treatment is necessary.

Transdermal Patch

Scopolamine is most commonly available as a transdermal delivery system, or patch. This form is applied to the skin behind the ear and is designed to release the medication slowly over a period of three days.

Injectable Solution

Scopolamine hydrobromide is available as an injectable solution. This form is administered by healthcare professionals via intramuscular, intravenous, or subcutaneous injection.

Ophthalmic Solution

This medication is also available as an ophthalmic solution, which is applied directly to the eye for specific medical purposes.

FDA Approval and Indications

Scopolamine is approved by the U.S. Food and Drug Administration (FDA) for the following uses in adults:

• Prevention of nausea and vomiting associated with motion sickness.
• Prevention of postoperative nausea and vomiting associated with recovery from anesthesia or surgery.

Safety Communications

The FDA has updated the labeling for scopolamine transdermal patches to include warnings about the risk of serious heat-related complications. The medication can decrease the body's ability to sweat, which may lead to heat stroke or significantly elevated body temperature, especially in hot environments or during strenuous exercise.

Regulatory Classification

Scopolamine is a prescription-only medication and is not a controlled substance. While it carries various warnings regarding side effects like vision changes or central nervous system effects, it does not currently have a Boxed Warning or a Risk Evaluation and Mitigation Strategy (REMS) program.

How the Patch Works

The scopolamine patch is a transdermal delivery system. It is designed to release a steady amount of medication through the skin and into the bloodstream over a period of three days (72 hours).

Application Instructions

• Apply the patch to a clean, dry, hairless area of skin behind the ear.
• Press the patch firmly for at least 30 seconds to ensure it sticks well.
• For motion sickness, the patch should be applied at least 4 hours before the activity that causes nausea.
• For surgery-related nausea, the patch is typically applied the evening before the procedure or as directed by a healthcare provider.

Important Precautions

• Hand washing: It is critical to wash your hands thoroughly with soap and water immediately after handling the patch. If the medication touches your eyes, it can cause temporary blurred vision and severely dilated pupils.
• MRI safety: Some patches may contain metal and must be removed before undergoing an MRI (Magnetic Resonance Imaging) to prevent skin burns at the application site.
• Maintenance: Do not cut the patch, as this will damage the delivery system and may cause too much medication to be released at once. If the patch falls off, discard it and apply a new one behind the ear.
• Replacement: If treatment is needed for more than three days, remove the old patch and apply a new one behind the opposite ear.