Articles, Blog

Methods of Drug Administration

March 10, 2020


Professor Dave again, let’s take some drugs. Before we dive into the specifics of all the
different classes of drugs, we have some more basic information to go over. First, let’s talk about precisely how drugs
are administered. There are many different ways that a drug
can enter the body, and the method selected has to do primarily with precisely where in
the body we need the drug to go, but also how quickly we need its effects to set in. This is determined by various healthcare professionals,
each of which have a different role, so to better understand their perspective, let’s
go over a basic overview of this information now. Drug delivery, or the method by which a drug
is administered to achieve a specific therapeutic effect, is quite complicated, as one might imagine. Administering the wrong drug, or the right
drug in the wrong way, can have serious consequences for a patient, and there are many factors at play. These include the age and weight of the individual,
their medical history, and so forth, and the wrong decision can result in an adverse reaction
to a drug, such as allergic or anaphylactic reactions. These are acquired hyperresponses of natural
bodily defenses to a foreign substance called an allergen, with anaphylaxis being the more
severe version, where massive amounts of histamine and other mediators of inflammation are released
throughout the body, which can be life-threatening. For reasons such as these, the safe delivery
of medications must follow the six rights of drug administration. These are basic guidelines that good health
professionals obey, and they are as follows. Right patient, right medication, right dose,
right route of administration, right time of delivery, and right documentation. Some of these guidelines fall into the realm
of highly specific medical training, so we won’t discuss them in this series, but the
route of administration will be of interest to us, so let’s examine that aspect. The main methods of drug administration we
will discuss are the enteral, topical, and parenteral routes, each of which have numerous
subcategories. Starting first with the enteral route, this
involves drugs being administered orally, which means through the mouth, or through
either nasogastric or gastronomy tubes, which are essentially feeding tubes that route directly
to the stomach, either through the nostril in the case of the former, or through the
belly in the case of the latter. In any of these cases, the drug ends up in
the stomach, with oral ingestion being preferred, leaving tubes to be utilized only if there
is some issue preventing oral ingestion, such as when the patient is unconscious and thus
unable to swallow. If administered through the mouth, this is
typically done with tablets or capsules, and this is arguably the easiest way to introduce
a drug to the body. If we can recall some things about the digestive
system, most of the absorption of nutrients occurs in the small intestine, which means
that these drugs must first make it through the ultra-acidic environment of the stomach
in order to maximize absorption and reach as many cells as possible. This is why most tablets have a hard, waxy
coating that withstands acidic environments, but will specifically dissolve in the basic
environment of the intestine, so as to be absorbed thoroughly. Apart from tablets and capsules, enteral drug
administration can involve the sublingual or buccal routes. These mean that the patient does not swallow,
but keeps the pill either under the tongue or in the oral cavity between the gum and
the cheek. The mucosa of the oral cavity is highly absorptive,
so drugs can enter the bloodstream this way, avoiding the acidic conditions of the stomach
in the process. With the enteral route covered, let’s move
on to the topical route. This involves the application of drugs to
the skin or the membranous linings of various orifices. So obviously any kind of cream that is rubbed
onto the skin falls into this category, as well as transdermal patches. In addition there is ophthalmic administration
to treat the eyes, such as with eye drops. Otic administration treats the ear, such as
with ear drops. Nasal administration means through the nostrils,
such as with various sprays, and then some drugs can be administered through the vagina
or rectum, typically in the form of a suppository. The topical route has a number of advantages,
namely that drug delivery is more targeted, as absorption is slow, and very little of
the drug makes it into areas of the body other then where the drug was applied, with the
exception of the nostrils and the rectum, which allow for a drug to circulate through
the bloodstream once absorbed. So some topical drugs have a highly local
effect, and others have a systemic effect. Finally there is the parenteral route. This is essentially any route other than what
we have already mentioned, and it typically involves a needle, which makes this a more
invasive method of administrating drugs. There are a few different ways to make the injection. The intradermal route deposits drugs into
the skin itself, and thus to the blood vessels within. The subcutaneous route is similar, the only
difference is that intradermal is more shallow, with injection into the dermis occurring at
a very shallow angle, while subcutaneous is deeper, with injection occurring at more of
a 45 degree angle. Then there is the intravenous route, where
drugs are injected directly into the bloodstream, and the intramuscular route, where the drugs
are injected into muscle tissue. To offer a brief comparison, intravenous administration
allows for high levels of the drug in the bloodstream immediately, which then decrease
over time as it is excreted, whereas oral administration starts off with zero concentration
in the bloodstream and slowly increases as absorption occurs, and then eventually also
decreases due to excretion. So between the enteral route, topical route,
and parenteral route, we have completed an introduction to the various ways in which
drugs can enter the body. The criteria for preferring one route over
another will continue to become more clear as we begin to look at specific drugs later
in the series, so for now, let’s move on to some more key concepts.

21 Comments

  • Reply Physics Lover March 10, 2020 at 10:58 am

    Nice video keep it up

  • Reply I don't like sand March 10, 2020 at 10:58 am

    No views 2 likes

  • Reply Techguy William March 10, 2020 at 11:18 am

    "Let's take some drugs" – Professor Dave 2020

  • Reply TrapStar March 10, 2020 at 11:20 am

    amazing video it was really good

  • Reply TrapStar March 10, 2020 at 11:20 am

    amazing video it was really entertaining

  • Reply Sky Li March 10, 2020 at 11:23 am

    Literally spit on my screen when he said, β€œLet’s take some drugs.”

  • Reply Sparkbomber March 10, 2020 at 11:24 am

    Very good video, I am surprised though that suppositories are a topical means of drug delivery. 😡

  • Reply I BE March 10, 2020 at 11:42 am

    Debate NathanOakley1980

  • Reply caitgems1 March 10, 2020 at 11:51 am

    I get mine dropped off using Uber.

  • Reply 2AHD Cat March 10, 2020 at 12:13 pm

    Drugs are bad, M'kay? lol

  • Reply Shahab Baloch March 10, 2020 at 12:35 pm

    i didnt get my answer professor dave how to find impirical formula?

  • Reply Ayad Ali March 10, 2020 at 1:24 pm

    First!

  • Reply Ayad Ali March 10, 2020 at 1:25 pm

    😱😱😱Let’s take some drugs?! Damn and this is a professor saying this!😱😱😱

  • Reply Docta Osiris March 10, 2020 at 2:01 pm

    I'm on a medication that has to dissolve on top of my tongue 😝 how could you forget about that route? 😲 πŸ˜‚ 🀣

    Great video though πŸ˜ŠπŸ‘

  • Reply Akshit Sahu March 10, 2020 at 2:05 pm

    I have finally arrived at a point of higher intellect that I finally procrastinate on Professor Dave’s videos rather than talk shows

  • Reply Doug Gale March 10, 2020 at 4:04 pm

    Vaginal suppositories eh? Wow. They don't tell guys about that πŸ˜€

  • Reply Zetsuke4 March 10, 2020 at 4:09 pm

    Do chemistry videos

  • Reply couchpotato March 10, 2020 at 4:16 pm

    Heroin is great intravenously

  • Reply Felixkeeg March 10, 2020 at 4:29 pm

    Me to a friend from university: "This is Professor Dave, he's great"
    clicks video
    "Professor Dave again, let's take some drugs"
    "Uhhhhhh, so yeah…"

  • Reply Mike Regan March 10, 2020 at 4:36 pm

    So, I shouldn't have listened to Elizabeth Holmes when she said her little device could, with a single teeny-tiny drop of blood, diagnose a problem then deliver the correct dosage of the appropriate drug?
    Damn. Gotta stop listening to cute blonds that drop out of college at 19.

  • Reply A4 22% March 10, 2020 at 7:06 pm

    Thank u for bringing up the rights of drug administration. Very good info there. That intro made me laugh out loud professor, u are the bestπŸ‘πŸ’ͺπŸ˜‹πŸ˜„πŸ˜‚

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