Scopolamine is a drug that can help alleviate nausea resulting from motion sickness or anesthesia. One way in which to administer the drug is through a scopolamine patch, which is placed on the skin so the drug can diffuse into the body. The way it appears to work is to block the nerve transmissions from the body that are telling the brain to feel nausea.
Nausea, which is the feeling of wanting to vomit, is a signal to the brain which is controlled by specific nerve sensors in the body. For example, a person who feels sick after eating bad food, or after drinking too much alcohol, may benefit from throwing up the substances, so the body tells the brain to vomit up the stomach contents. Motion sickness and some anesthetic drugs can also interfere with the body's ability to produce nausea and vomiting, but this may be accidental, rather than a deliberately useful benefit to the body.
Interfering with the body's assessment of when to feel sick and when to vomit can therefore be useful in medicine. A scopolamine patch does just this, helping to remove the feeling of nausea in a patient, which improves his or her comfort. People who experience severe motion sickness when traveling, or those who are likely to feel nauseous after going under anesthetics, can use a scopolamine patch.
Typically, a scopolamine patch is designed to be placed on the skin behind the ear. Each patch has several layers, which all perform different roles in the patch mechanism. Normally there is one covering layer, which is removed to reveal the sticky layer that is placed onto the skin. Under this sticky layer is a membrane which allows a suitable dose of drug from underneath the membrane out into the skin over time. Farthest away from the skin is the outer layer which is usually colored to be unobtrusive on skin tone.
People using scopolamine patches can transfer the drug to the eyes if the hands are contaminated with the drug. This can cause dilation of the pupils and blur the vision of the patient, so hand-washing is important after each use of a patch. The side effects of scopolamine patches, apart from this problem, can include serious issues like mental disturbances and hallucinations. A dryness in the mouth, skin rash and problems urinating normally are also possible. If a scopolamine patient stops using the drug suddenly, he or she may experience side effects like dizziness and vomiting.