Using Skin Patch Medicines Safely

The Full Story

Many people benefit from drugs that are absorbed slowly and regularly. Some find it difficult to swallow pills. Remembering to take a drug frequently is hard for others.

Fortunately, some drugs can be taken by putting on a skin patch. Using these "transdermal" drugs is simple. But this type of patch is actually a sophisticated drug delivery system. It is designed to release small quantities of drug into the blood stream over a long period of time. Drug is absorbed from the patch, through the outer layers of skin, and into deeper layers. There, it is absorbed into the blood stream and circulated through the body.

These "skin patch" drugs include pain relievers, nicotine, hormones, and drugs to treat angina and motion sickness. There are several advantages to taking drugs via patches:

• They are absorbed at a fairly steady rate.
• You don't have to remember to swallow frequent doses.
• You can take them even if you have an upset stomach, as you might with motion sickness.

Scopolamine, a motion sickness drug, was the first to be used in a skin patch. Victims of motion sickness place a patch behind the ear, ideally a few hours before symptoms are likely to start. The same patch can remain in place for up to three days. A brand name is Transderm Scōp^®.

Nicotine patches are used to help people stop smoking. They provide a slow, steady amount of nicotine to the blood stream. This takes the place of nicotine from inhaling cigarette smoke and helps prevent withdrawal symptoms. Several strengths are available. People can gradually decrease the nicotine dose they receive from patches. The goal is to stop using nicotine altogether. Some people who are trying to stop smoking find the steady amount of nicotine from patches a better treatment than intermittent nicotine use with gum or lozenges. Nicotine patches are available without a prescription. Some brand names are Habitrol^®, Nicoderm^®, Nicoderm CQ^®, and Nicotrol^®. Nicotine patches also are available in generic form.

Diclofenac in a patch is used to relieve minor pain. Examples are sprained ankles and bad bruises. Unlike other patches, diclofenac patches are put on the skin just over the area that hurts. Continuing pain relief can make it easier to carry out normal activities. The brand name for diclofenac patches is Flector^®.

Nitroglycerin patches are used by people who have angina. This is chest pain caused by narrow blood vessels in the heart (coronary artery disease). Nitroglycerin relaxes those blood vessels so the heart gets more blood and more oxygen. Nitroglycerin patches can prevent angina pain but they are not used to treat chest pain. These patches usually are worn for 12 - 14 hours a day and then removed until the next day. Some brand names are Minitran^®, Nitro-Dur^®, Nitrodisc^®, and Transderm-Nitro^®.

Fentanyl patches contain a strong narcotic. They are used only to treat chronic, severe pain. Several dosage strengths are available; patches need to be replaced only every three days. Duragesic^® is a brand name.

The active ingredient in transdermal patches has the same benefits as those drugs in other forms. Likewise, they carry the same potential side effects and risks. Before taking any drug in a patch, ask your doctor about:

• Expected effects.
• Possible side effects.
• Possible drug interactions.
• Drugs or foods to avoid.
• Environmental factors to avoid, for example, staying out of the sun.
• When you should call for an urgent appointment. For example, could a fever put you at risk for problems with this drug?
• How long will the drug be active after you remove a patch?

There are special precautions when using transdermal patches.

• Apply the patch to clean, dry, unbroken skin. If the skin is broken or irritated, too much drug could be absorbed.
• Be sure the patch is applied firmly. It may take 20 or 30 seconds to get all of the adhesive to stick firmly in place.
• Wash your hands after applying a patch to yourself or someone else.
• Use only one patch at a time unless the instructions say otherwise.
• If you need an MRI, the patch may need to be removed during your test. Check with your doctor or x-ray technician.
• If you develop skin irritation from the adhesive, put the next patch in another area. Check with your doctor about what to do next.
• When your remove a skin patch, fold it so the adhesive edges stick together. Throw it away so that children or pets cannot get to it.
• Gently wash the area with soap and water.

People who use transdermal patches can suffer an overdose if the patch is broken or cut open; too much medicine gets on and through the skin. Wearing too many patches can cause an overdose, too.

Children have been poisoned by skin patches in a number of ways:

• Taking skin patches from the trash and sucking on them. One youngster had several fentanyl patches stuck to the roof of her mouth. 
• Having adult patches stuck to their skin. This has happened when children unknowingly rolled over skin patches that came off in an adult's bed.
• Finding and chewing on skin patches, just as they find and mouth anything else that looks interesting. 

If you swallow, chew, or suck on a transdermal patch, use the webPOISONCONTROL^® online tool for guidance or call Poison Control at 1-800-222-1222.

The you suspect an overdose from a patch on the skin, remove the patch and wash the skin with soap and water. Then, use webPOISONCONTROL for guidance online or call Poison Control right away at 1-800-222-1222. Poison specialists will tell you exactly what to do. If you have to go to the hospital, Poison Control will call ahead to the emergency room to provide treatment recommendations. It's important to consult with Poison Control, even if the person seems OK. Even after taking the patch off, some drug remains in the body. Poison Control will stay in touch with you to be sure that no problems develop.

Rose Ann Gould Soloway, RN, BSN, MSEd, DABAT emerita
Clinical Toxicologist