Scopolamine

Scopolamine

Definition

Scopolamine, also called hyoscine hydrobromide, is used in cancer treatment to prevent nausea and vomiting that results from movement of the head.

Purpose

Chemotherapy causes nausea and vomiting in many people. These conditions can occur for several different reasons. Scopolamine is used to treat nausea and vomiting that result from movement of the head. In many ways, this type of nausea is similar to motion sickness.

Description

Scopolamine is a natural product and is familiar to many people as a motion sickness medicine. In its most common form, it comes as a patch that a person with motion sickness wears behind the ear. It is also known by the brand names Transderm-Scop and Transderm-V.

As a motion sickness drug, scopolamine has been used for many years with few side effects. It is approved by the United States Food and Drug Administration (FDA), and its cost is usually covered by insurance. In cancer treatment, scopolamine is used to treat a particular type of nausea and vomiting that occur as a result of chemotherapy.

Scopolamine is classified as an anticholinergic drug. This means it works by blocking the nerve impulses that send information from the part of the inner ear that controls the sense of balance. In motion sickness, a person vomits because conflicting information arrives in the brain from the inner ear and the eye. Some chemotherapy drugs also cause the brain to receive conflicting information, so that when patients move their head, they feel nauseated. People vary in their sensitivity to this condition. This drug is effective in helping most people control nausea and vomiting that arises from this source.

Recommended dosage

Scopolamine comes in a patch that the patient applies behind the ear. The patch stays in place for three days and releases a continuous supply of the drug. To be effective, the patch must be applied at least four hours before chemotherapy is begun. After three days, the patch is removed. Unused patches should be stored at room temperature.

Precautions

People applying or removing a scopolamine patch should wash their hands well immediately after handling the patch so that they do not accidentally transfer any of the drug to other parts of their body (for example, by rubbing their eyes). Scopolamine should not be used in children, and should be used with caution in the elderly.

Side effects

About 65% of the people who use scopolamine get a dry mouth. About 17% of people report feeling drowsy from the drug. Other less common side effects include blurred vision, disorientation, restlessness, confusion, dizziness, difficulty urinating, skin rash, dry, red, itchy eyes, and narrow angle glaucoma.

Interactions

Many drugs interact with nonprescription (over-the-counter) drugs and herbal remedies. Patients should always tell their health care providers about these remedies, as well as prescription drugs they are taking. Patients should also mention if they are on a special diet such as low salt or high protein.

Scopolamine interferes with the absorption of ketoconazole (Nizoral), an antifungal drug, sometimes used to treat prostate cancer . It may also interact with other anticholinergic drugs (drugs that block nerve impulses), antidepressants, and antihistamines.

Tish Davidson, A.M.

KEY TERMS

Narrow-angle glaucoma

—Glaucoma is a disease where increased pressure in the eye causes damage and changes to the field of vision. Narrow-angle refers to a specific type of damage.