To start, let's talk about the different ways drugs can be administered. You're probably familiar Routes of medication administration are described in the table below. So, they may have to be given by injection instead. The administration of a medicine is a common but important clinical procedure. But don't take our word for it, register for free and unlock 7 days of unlimited. Drug Administration - Explore from the MSD Manuals - Medical Consumer Version. Drugs are introduced into the body by several routes. They may be.
Take to the Routes Medicine: Various
An intravenous injection can be more difficult to administer than a subcutaneous or intramuscular injection because inserting a needle or catheter into a vein may be difficult, especially if the person is obese. When given intravenously, a drug is delivered immediately to the bloodstream and tends to take effect more quickly than when given by any other route. Consequently, health care practitioners closely monitor people who receive an intravenous injection for signs that the drug is working or is causing undesired side effects.
Also, the effect of a drug given by this route tends to last for a shorter time. Therefore, some drugs must be given by continuous infusion to keep their effect constant. For the intrathecal route, a needle is inserted between two vertebrae in the lower spine and into the space around the spinal cord.
The drug is then injected into the spinal canal. A small amount of local anesthetic is often used to numb the injection site.
This route is used when a drug is needed to produce rapid or local effects on the brain, spinal cord, or the layers of tissue covering them meninges —for example, to treat infections of these structures. Anesthetics and analgesics such as morphine are sometimes given this way. A few drugs are placed under the tongue taken sublingually or between the gums and teeth bucally so that they can dissolve and be absorbed directly into the small blood vessels that lie beneath the tongue.
These drugs are not swallowed. The sublingual route is especially good for nitroglycerin , which is used to relieve angina, because absorption is rapid and the drug immediately enters the bloodstream without first passing through the intestinal wall and liver.
However, most drugs cannot be taken this way because they may be absorbed incompletely or erratically. Many drugs that are administered orally can also be administered rectally as a suppository.
In this form, a drug is mixed with a waxy substance that dissolves or liquefies after it is inserted into the rectum.
A suppository is prescribed for people who cannot take a drug orally because they have nausea, cannot swallow, or have restrictions on eating, as is required before and after many surgical operations.
Drugs that can be administered rectally include acetaminophen for fever , diazepam for seizures , and laxatives for constipation. Drugs that are irritating in suppository form may have to be given by injection. Some drugs may be administered vaginally to women as a solution, tablet, cream, gel, suppository, or ring. The drug is slowly absorbed through the vaginal wall.
This route is often used to give estrogen to women during menopause to relieve vaginal symptoms such as dryness, soreness, and redness.
Drugs used to treat eye disorders such as glaucoma, conjunctivitis, and injuries can be mixed with inactive substances to make a liquid, gel, or ointment so that they can be applied to the eye. Liquid eye drops are relatively easy to use but may run off the eye too quickly to be absorbed well. Gel and ointment formulations keep the drug in contact with the eye surface longer, but they may blur vision.
Solid inserts, which release the drug continuously and slowly, are also available, but they may be hard to put in and keep in place. Ocular drugs are almost always used for their local effects.
For example, artificial tears are used to relieve dry eyes. Other drugs for example, those used to treat glaucoma [see Table: Drugs Used to Treat Glaucoma ], such as acetazolamide and betaxolol , and those used to dilate pupils, such as phenylephrine and tropicamide produce a local effect acting directly on the eyes after they are absorbed through the cornea and conjunctiva.
Some of these drugs then enter the bloodstream and may cause unwanted side effects on other parts of the body.
Drugs used to treat ear inflammation and infection can be applied directly to the affected ears. Ear drops containing solutions or suspensions are typically applied only to the outer ear canal. Before applying ear drops, people should thoroughly clean the ear with a moist cloth and dry it.
Unless the drugs are used for a long time or used too much, little of the drugs enter the bloodstream, so bodywide side effects are absent or minimal. Drugs that can be given by the otic route include hydrocortisone to relieve inflammation , ciprofloxacin to treat infection , and benzocaine to numb the ear. If a drug is to be breathed in and absorbed through the thin mucous membrane that lines the nasal passages, it must be transformed into tiny droplets in air atomized.
Once absorbed, the drug enters the bloodstream. Drugs administered by this route generally work quickly. Some of them irritate the nasal passages. Drugs that can be administered by the nasal route include nicotine for smoking cessation , calcitonin for osteoporosis , sumatriptan for migraine headaches , and corticosteroids for allergies.
Drugs administered by inhalation through the mouth must be atomized into smaller droplets than those administered by the nasal route, so that the drugs can pass through the windpipe trachea and into the lungs. How deeply into the lungs they go depends on the size of the droplets. Smaller droplets go deeper, which increases the amount of drug absorbed. Inside the lungs, they are absorbed into the bloodstream. Relatively few drugs are administered this way because inhalation must be carefully monitored to ensure that a person receives the right amount of drug within a specified time.
In addition, specialized equipment may be needed to give the drug by this route. Usually, this method is used to administer drugs that act specifically on the lungs, such as aerosolized antiasthmatic drugs in metered-dose containers called inhalers , and to administer gases used for general anesthesia. Similar to the inhalation route, drugs given by nebulization must be aerosolized into small particles to reach the lungs.
Nebulization requires the use of special devices, most commonly ultrasonic or jet nebulizer systems. Using the devices properly helps maximize the amount of drug delivered to the lungs. Drugs that are nebulized include tobramycin for cystic fibrosis , pentamidine for pneumonia caused by Pneumocystis jirovecii , and albuterol for asthma attacks. Side effects can include those that occur when the drug is deposited directly in the lungs such as cough, wheezing, shortness of breath, and lung irritation , spread of the drug into the environment possibly affecting people other than the one taking the drug , and contamination of the device used for nebulization particularly when the device is reused and inadequately cleaned.
Using the device properly helps prevent side effects. Drugs applied to the skin are usually used for their local effects and thus are most commonly used to treat superficial skin disorders, such as psoriasis , eczema , skin infections viral , bacterial , and fungal , itching , and dry skin.
The drug is mixed with inactive substances. Depending on the consistency of the inactive substances, the formulation may be an ointment, cream, lotion, solution, powder, or gel see Treatment of Skin Disorders: Some drugs are delivered bodywide through a patch on the skin. These drugs are sometimes mixed with a chemical such as alcohol that enhances penetration through the skin into the bloodstream without any injection. Through a patch, the drug can be delivered slowly and continuously for many hours or days or even longer.
As a result, levels of a drug in the blood can be kept relatively constant. Patches are particularly useful for drugs that are quickly eliminated from the body because such drugs, if taken in other forms, would have to be taken frequently. So one that might come to mind pretty easily when you think about, maybe hard-core drugs is injection, so we'll talk about that.
The other main routes are oral entry and inhalation. Oral entry means that you swallow something, so that could be a pill or some alcohol. Either way you're eating or drinking it. You're ingesting it in some way, and this is one of the slowest routes of entry because it has to go through your gastrointestinal tract in order to get absorbed by your bloodstream, which can take about half an hour, give or take a few minutes.
Inhalation, on the other hand, which is when you snort or smoke or breathe in the drugs is actually much faster because once you inhale it, it pretty much goes straight to your brain.
It can be there within 10 seconds, and then you start feeling the effects. So this would be, a lot of times, tobacco or cocaine is often snorted.
And finally the most direct route is injection. With injection, we're usually talking about intravenous injection, which means it goes right into a blood vein.
This begins to take effect within seconds. Intravenous injection can be very dangerous because you're much more likely to inject bacteria or other unexpected toxins along with the drugs, especially if you're using unsterilized paraphernalia.
So if someone else has used the needle before you, then this increases the likelihood you'll be exposed to something harmful, such as HIV. OK, so those are the three most common routes of entry and I'm just going to mention two more that are moderately common, transdermal and intramuscular. Transdermal entry means that the drug is absorbed through the skin.
This is how patches like the nicotine patch, for example, works. The drug in the patch has to be pretty potent and it can be released into the bloodstream over several hours. Intramuscular entry means that a needle is stuck directly into the muscle, so before we talked about intravenous injection, this is intramuscular.
Depending on the chemical properties of the drug, this method can deliver the drugs to your system very quickly or more gradually. One example of a really quick entry for intramuscular injection is when an EpiPen is administered to someone experiencing a severe allergic reaction.
So when people have such a reaction, their airway start to close up, so they need to get a dose of epinephrine into their body to open their airways as quickly as possible.
Routes of drug entry
Prescription drugs can be taken in multiple ways, including oral, enteral, Various pills in blister packs. Jorg Greuel/Digital Vision/Getty Images. There are many routes of medication administration (the way that a drug is. A route of administration in pharmacology and toxicology is the path by which a drug, fluid, The route or course the active substance takes from application location to the . Rate of extent of absorption of the drug from different routes. The IV route was linked with higher rates of all adverse events, the SC the appropriate and flexible use of different routes of administration for.