Drugs That Are Administered Transdermally
Transdermal drug administration refers to substances that are absorbed through the skin.
Some of the most common examples of these are nicotine patches or patches that contain painkillers, such as prescription opioids that release slowly over time in order to control chronic pain. It can also refer to implants placed just under the top layers of skin or simple creams rubbed onto the skin.
This method of treatment has been gaining popularity over treatment with pills taken orally. Having patients take pills multiple times every day increases the risk that they’ll forget or take too many, which can result in dangerous symptoms, especially in the case of opioids. However, there are few substances that can be successfully administered this way due to the fact that the skin is meant to protect the body from outside entities. A drug must pass through many layers of skin to get to the bloodstream and therefore needs to be especially potent to work in this manner.
- Fentanyl (opioid)
- Nitroglycerine (antianginal)
- Buprenorphine (opioid)
- Ensam (antidepressant)
- Daytrana (transdermal Ritalin)
- Scopolamine (anti-nausea)
- Estrogen and testosterone
- Contraceptive medication
- Clonidine (blood pressure medication)
- Rivastigmine (Alzheimer’s treatment)
The medication in these patches tends to last for many hours, days, or even weeks before they need to be changed. Another benefit to this type of drug administration is that it’s more difficult to abuse substances that come in patches or transplants; however, it’s not impossible.
Transdermal Drug Abuse
There have been cases of people obtaining transdermal patches for the purposes of drug abuse – particularly those that contain opioid medications. Fentanyl is an extremely potent opioid that has become popular for abuse in recent years. It’s considered to be 50 times more potent than pure heroin, and therefore is typically only given out in highly controlled forms such as transdermal patches and lozenges for cases of severe pain, such as to cancer patients.
However, drugs like fentanyl in transdermal patch form can still be abused. Inside a fentanyl patch is a small amount of gel containing the drug, which can be ingested orally if the patch is torn open. Even a tiny amount of this gel can produce an intense euphoric high in people who have already developed a tolerance to opioids. An individual without a tolerance would likely overdose and possible die from doing this due to the potency of the drug.
Deaths from prescription opioids have surpassed cocaine and heroin to become the most common cause of overdose death in the US. According to the National Institute on Drug Abuse, around 19,000 people died from an prescription opioid overdose in 2014 alone – more than triple the number of deaths in 2001. These drugs are also very addictive, increasing the chance that an overdose will occur.
Anyone obtaining transdermal opioids like fentanyl patches is likely already addicted to opioid drugs and seeking a better high after developing a serious tolerance to less potent medications like Vicodin or even heroin. At this point, professional addiction treatment will be needed in order to recover. Getting on the road to recovery from an opioid addiction can be very difficult, but the risks of overdose and other health problems from these drugs are too severe to ignore. Addiction treatment programs are designed to make the recovery process as easy as possible.
Transdermal patches were approved by the Food and Drug Administration (FDA) for the first time in 1979. The very first prescription patch was to treat motion sickness; since then, the popularity of transdermal patches for prescription medications has skyrocketed. On average, a new transdermal patch is approved by the FDA every 2.2 years.
Patches can contain a large amount of a prescription medication; they then time-release the dose over a day or even several days. Patches have been made to help with smoking cessation, for birth control, to control blood pressure, for pain relief, and even to treat attention deficit hyperactive disorder (ADHD).
When prescription medications are administered through transdermal patches, the body has a consistent supply of the necessary medication. The person with the prescription does not have to remember to take their medicine orally or intravenously at a certain time of day; instead, they put the patch on once, and it stays there for the length of the dose.
However, some prescription transdermal patches can lead to addiction or abuse. Below are some common questions about transdermal drugs and their potential for addiction or abuse.
Drugs that can lead to abuse or addiction, which come in transdermal forms, include:
- Fentanyl: a potent opioid painkiller, which is increasingly abused among people struggling with opioid addiction
- Buprenorphine: a partial opioid-agonist used to help people struggling with opioid addiction end their physical dependence but can also be abused
- Methylphenidate: a stimulant prescribed to treat ADHD, but can be habit-forming for people who do not have ADHD
- Nicotine patches: designed to help a person end their addiction to cigarettes or tobacco (Some studies have shown that the release of nicotine into the blood does not actually help end the addiction; it just helps the person stop smoking.)
The skin is a large organ that is very absorbent, so other drugs could potentially be put on the skin and ingested that way. However, it is slower than many ingestion methods like smoking or snorting, so it is not a common form of substance abuse.
Fentanyl is especially prone to abuse because it is stronger than heroin. Fentanyl patches can contain up to three days of medicine, making them a prime target for substance abuse. The patches are cut up and chewed, brewed like a tea, mixed with water and injected, or several are placed on the skin at once. Because fentanyl is a very potent narcotic that is designed to treat pain in people who need long-term relief from chronic pain, abusing the patches in this fashion can rapidly lead to overdose and death.
Buprenorphine patches have also been abused this way, to bypass time-release properties and achieve a high.
Can transdermal drug abuse cause skin issues?
Yes. Even when taking transdermal drugs as prescribed and under physician supervision, skin irritation can occur. Other side effects are typically reduced when drugs are administered transdermally, but abuse can increase the likelihood of these effects.
Types of skin irritation found among people who use transdermal drugs include:
- Dermatitis, or inflammation of the skin due to contact with mild irritants
- Allergic reactions on the skin
- Superficial reddening of the skin due to burst capillaries (erythema)
- Dry, cracked, flaking, or scaling of the skin
- Swelling due to edema (fluid retention) in reaction to skin infection
- Necrosis (tissue death) around untreated areas on the skin
Is sublingual (under the tongue) the same as transdermal?
No, sublingual and transdermal administration are different. Taking medications by dissolving them under the tongue involves the salivary glands; mucous membranes in the mouth absorb the drug once it has been dissolved. Transdermal administration of drugs means placing a patch on the epidermis, or the outer layer of skin; the drug is then absorbed through the skin and into the bloodstream, without involving mucous membranes.
Are drug lollipops absorbed transdermally?
No, lollipops are absorbed through the mucous membranes of the mouth, or through transmucosal administration. This involves fewer layers of flesh for the drug to pass through, so medications like fentanyl are absorbed faster through this route.
Can LSD be absorbed through the skin?
LSD is typically ingested orally, by dissolving a tab or piece of candy on or under the tongue. Typical routes mean that LSD is absorbed transmucosally or sublingually. However, LSD is a liquid drug, so the substance can be placed directly on the skin and absorbed. Direct contact with liquid LSD can produce hallucinations, intoxication, and other effects of LSD, at unregulated doses.
That said, rumors occasionally circulate about LSD in various forms, especially those targeted at teenagers or young children. One rumor suggested that LSD temporary tattoos were being sold by dealers, and children were getting high on the hallucinogen through their skin. Snopes found this rumor to be false.