Routes of Drug Administration: Oral, Topical, Inhalation & Injection Video

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  • 0:35 Oral Drug Use
  • 1:42 Skin & Mucous Membranes
  • 3:40 Inhalation & Injection
  • 5:15 Lesson Summary
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Lesson Transcript
Instructor: Artem Cheprasov
The way by which illicit drugs can be administered or taken into the body are numerous. These routes include the oral route, transdermal, inhalation, and intravenous injection.

Different Ways to Take a Drug

Over the course of your life, you have probably taken many different kinds of medication. Some you took by mouth, like an antibiotic. Maybe you have asthma and use an inhaler. Perhaps you've tried quitting smoking and are using a patch. Or in a worst-case scenario, you might know of someone who has been hospitalized and been given drugs intravenously, that is to say, into a vein.

The different ways that drugs used to treat you can be administered precisely match the ways illicit substances can be absorbed into the system for a desired effect, which will be the subject of our lesson.

Oral Drug Use

Oral administration (PO), ingestion of a drug by mouth and into the gastrointestinal tract, is one way by which a drug can be taken. PO stands for per os, or by mouth.

The drug travels from your mouth, into the esophagus, then into the intestines. That is why, more technically, the oral route is part of the enteral route, with 'enteral' referring to the intestines these drugs eventually reach.

Along the way to the intestines, the pill or capsule is broken apart and its contents dissolved into a mixture that is then transported into the bloodstream. Once in the bloodstream, the drug will then act on various organs in your body, including the brain.

I told you all of that because you can clearly tell this is a long-winded route, like a really long road trip. It takes a while for the drug to actually begin exerting its effects if it's taken orally. This is especially true if a person's stomach is full of food. The food needs to be digested as well, and it acts as sort of a buffer to help minimize the rate at which the drug enters the body.

The Skin and Mucous Membranes

Another kind of route of drug administration is known as transdermal, or through the skin. 'Dermal-' references the skin, and 'trans-' means it goes through something, like the Trans-Siberian Railway goes through Siberia.

Anyways, you've almost definitely seen advertisements for something like nicotine patches. These guys use transdermal technology. These patches are a good way to deliver a continuous and sustained release of a substance over time.

Another well-known transdermal medicine is the fentanyl patch. This is an opioid analgesic, a drug that relieves pain, and it's very powerful. It's an established fact that this class of drugs is abused a lot. You'd be surprised at some of the ways people try to abuse these pain-relieving patches. Some methods are obvious, like putting more than one patch on, or changing the patches more frequently than indicated.

But some people get creative in order to elicit a high from these opioid patches and put themselves at a very real risk of death from overdose. Methods of patch abuse include:

  • Chewing or swallowing the patches
  • Diluting the fentanyl into tea
  • Inhaling the gel that makes up the patches
  • Extracting the fentanyl and injecting it into a vein
  • Inserting the patches into the rectum

Why people do this will make sense with the next three ways by which drugs are absorbed.

One reason is that besides the skin, some drugs can cross the mucous membranes of your body and enter the bloodstream. These are areas of the body that includes the lips, insides of the nose, and mouth. Sublingual lozenges are a great example of this. Sublingual means under the tongue. The drug dissolves under the tongue and enters the bloodstream after making its way through the thin mucous membranes under the tongue. This typically results in a faster effect than if you were to simply swallow a medicine.

Inhalation and Injection

But if a person wants even faster effects, then they may employ inhalation of the drug. This is a method of drug delivery by way of the lungs. Drugs that are taken in by inhalation can exert their effects in less than a minute. This is why smoking a drug is usually associated with greater chances of developing dependency on a drug.

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