Jump to content

Route of administration: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
No edit summary
No edit summary
Line 1: Line 1:
{{prose|date=March 2010}}
JESSICA CORK!!!! :) {{prose|date=March 2010}}
{{Refimprove|date=July 2007}}
{{Refimprove|date=July 2007}}


Revision as of 20:59, 20 September 2012

JESSICA CORK!!!! :)

A route of administration in pharmacology and toxicology is the path by which a drug, fluid, poison, or other substance is taken into the body.[1]

Classification

Routes of administration are usually classified by application location (or exposition). The route or course the active substance takes from application location to the location where it has its target effect is usually rather a matter of pharmacokinetics (concerning the processes of uptake, distribution, and elimination of drugs). Nevertheless, some routes, especially the transdermal or transmucosal routes, are commonly referred to routes of administration. The location of the target effect of active substances are usually rather a matter of pharmacodynamics (concerning e.g. the physiological effects of drugs[2]). Furthermore, there is also a classification of routes of administration that basically distinguishes whether the effect is local (in "topical" administration) or systemic (in "enteral" or "parenteral" administration).

Application location

Gastrointestinal/enteral

Administration through the gastrointestinal tract is sometimes termed enteral or enteric administration (strictly meaning 'through the intestines'). Enteral/enteric administration usually includes oral[3] (through the mouth) and rectal (into the rectum)[3] administration, in the sense that these are taken up by the intestines. However, uptake of drugs administered orally may also occur already in the stomach, why gastrointestinal (along the gastrointestinal tract) may be a more fitting word for this route of administration. Furthermore, some application locations often classified as enteral, such as sublingual[3] (under the tongue) and sublabial or buccal (between the cheek and gums/gingiva), are taken up in the proximal part of the gastrointestinal tract without reaching the intestines. Strictly enteral administration (directly into the intestines) can be used for systemic administration, as well as local (sometimes termed topical), such as in enema where e.g. contrast media is infused into the intestines for imaging. However, in the classification system basically distinguishing substances by location of their effects, the term enteral is reserved for substances with systemic effects.

Many drugs as tablets, capsules, or drops are taken orally. Administration methods directly into the stomach include those by gastric feeding tube or gastrostomy. Substances may also be placed into the small intestines, as with a duodenal feeding tube and enteral nutrition.Some enteric coated tablets will not dissolve in stomach but it is directed to the intestine because the drug present in the enteric coated tablet causes irritation in the stomach.

Central nervous system

  • epidural (synonym: peridural) (injection or infusion into the epidural space), e.g. epidural anesthesia
  • intracerebral (into the cerebrum) direct injection into the brain. Used in experimental research of chemicals[4] and as a treatment for malignancies of the brain.[5] The intracerebral route can also interrupt the blood brain barrier from holding up against subsequent routes.[6]
  • intracerebroventricular (into the cerebral ventricles) administration into the ventricular system of the brain. One use is as a last line of opioid treatment for terminal cancer patients with intractable cancer pain.[7]

Other locations

Route from application to target

The route or course the active substance takes from application location to the location where it has its target effect is usually rather a matter of pharmacokinetics (concerning the processes of uptake, distribution, and elimination of drugs). Nevertheless, the following routes are commonly referred to as routes of administration:

Local or systemic effect

Routes of administration can also basically be classified whether the effect is local (in topical administration) or systemic (in enteral or parenteral administration):

  • topical: local effect, substance is applied directly where its action is desired.[9] Sometimes, however, the term topical is defined as applied to a localized area of the body or to the surface of a body part,[10] without necessarily involving target effect of the substance, making the classification rather a variant of the classification based on application location.
  • enteral: desired effect is systemic (non-local), substance is given via the digestive tract.
  • parenteral: desired effect is systemic, substance is given by routes other than the digestive tract.

Topical

Enteral

In this classification system, enteral administration is administration that involves any part of the gastrointestinal tract and has systemic effects:

Parenteral

Advantages and disadvantages

There are advantages and disadvantages to each route of administration

Inhalation

Advantages

  • The advantage of using an inhalatational method is that it allows the dose to be controlled more effectively
  • User can titrate (regulate the amount of drug they are receiving)[12]

Disadvantages

  • Its a slower route of action, it has to be taken into the lungs, and then travels to the systemic circulation from there.

Injection

Injection encompasses intravenous (IV), intramuscular (IM), and subcutaneous (subcut) [13]

Advantages

  • Fast: 15–30 seconds for IV, 3–5 minutes for IM and subcutaneous (subcut)
  • 100% bioavailability
  • suitable for drugs not absorbed by the digestive system or those that are too irritant (anti-cancer)
  • One injection can be formulated to last days or even months, e.g., Depo-Provera, a birth control shot that works for three months
  • IV can deliver continuous medication, e.g., morphine for patients in continuous pain, or saline drip for people needing fluids

Disadvantages

  • Onset of action is quick, hence more risk of addiction when it comes to injecting drugs of abuse
  • Patients are not typically able to self-administer
  • Belonephobia, the fear of needles and injection.
  • If needles are shared, there is risk of HIV and other infectious diseases
  • It is the most dangerous route of administration because it bypasses most of the body's natural defenses, exposing the user to health problems such as hepatitis, abscesses, infections, and undissolved particles or additives/contaminants
  • If not done properly, potentially fatal air boluses (bubbles) can occur.
  • Need for strict asepsis

Uses

  • Some routes can be used for topical as well as systemic purposes, depending on the circumstan. For example, inhalation of asthma drugs is targeted at the airways (topical effect), whereas inhalation of volatile anesthetics is targeted at the brain (systemic effect).
  • On the other hand, identical drugs can produce different results depending on the route of administration. For example, some drugs are not significantly absorbed into the bloodstream from the gastrointestinal tract and their action after enteral administration is therefore different from that after parenteral administration. This can be illustrated by the action of naloxone (Narcan), an antagonist of opiates such as morphine. Naloxone counteracts opiate action in the central nervous system when given intravenously and is therefore used in the treatment of opiate overdose. The same drug, when swallowed, acts exclusively on the bowels; it is here used to treat constipation under opiate pain therapy and does not affect the pain-reducing effect of the opiate.
  • Enteral routes are generally the most convenient for the patient, as no punctures or sterile procedures are necessary. Enteral medications are therefore often preferred in the treatment of chronic disease. However, some drugs can not be used enterally because their absorption in the digestive tract is low or unpredictable. Transdermal administration is a comfortable alternative; there are, however, only a few drug preparations that are suitable for transdermal administration.
  • In acute situations, in emergency medicine and intensive care medicine, drugs are most often given intravenously. This is the most reliable route, as in acutely ill patients the absorption of substances from the tissues and from the digestive tract can often be unpredictable due to altered blood flow or bowel motility.

See also

References

  1. ^ TheFreeDictionary.com > route of administration Citing: Jonas: Mosby's Dictionary of Complementary and Alternative Medicine. 2005, Elsevier.
  2. ^ Lees P, Cunningham FM, Elliott J (2004). "Principles of pharmacodynamics and their applications in veterinary pharmacology". J. Vet. Pharmacol. Ther. 27 (6): 397–414. doi:10.1111/j.1365-2885.2004.00620.x. PMID 15601436.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ a b c "Oklahoma Administrative Code and Register > 195:20-1-3.1. Pediatric conscious sedation utilizing enteral methods (oral, rectal, sublingual)". Retrieved 2009-01-18.
  4. ^ "MDMA (ecstasy) metabolites and neurotoxicity: No occurrence of MDMA neurotoxicity from metabolites when injected directly into brain, study shows". Neurotransmitter.net. Retrieved 2010-08-19.
  5. ^ USA (2010-07-06). "A potential application for the intracerebral injection of drugs entrapped within liposomes in the treatment of human cerebral gliomas". Pubmedcentral.nih.gov. Retrieved 2010-08-19.
  6. ^ "Blood–brain barrier changes following intracerebral injection of human recombinant tumor necrosis factor-α in the rat". Springerlink.com. Retrieved 2010-08-19.
  7. ^ "Acute Decreases in Cerebrospinal Fluid Glutathione Levels after Intracerebroventricular Morphine for Cancer Pain". Anesthesia-analgesia.org. 1999-06-22. Retrieved 2010-08-19.
  8. ^ "Fenway Community Health". Fenway Health. Retrieved 2010-08-19.
  9. ^ Merriam-Webster Online Dictionary > topical. Retrieved April 26, 2010.
  10. ^ thefreedictionary.com > topical Citing: The American Heritage Dictionary of the English Language, Fourth Edition, 2000
  11. ^ Malenka, Eric J. Nestler, Steven E. Hyman, Robert C. (2009). Molecular neuropharmacology : a foundation for clinical neuroscience (2nd ed. ed.). New York: McGraw-Hill Medical. ISBN 978-0-07-148127-4. {{cite book}}: |edition= has extra text (help)CS1 maint: multiple names: authors list (link)
  12. ^ "SICA". Nebraskaprevention.gov. Retrieved 2012-03-30.
  13. ^ http://www.ismp.org/Tools/errorproneabbreviations.pdf

JESSICA CORK. Nursing Student 2012 :)


Retrieved from "https://en.wikipedia.org/w/index.php?title=Route_of_administration&oldid=513772865"