Enteral administration on:
[Wikipedia]
[Google]
[Amazon]
Enteral administration is food or drug administration via the
Enteral administration is food or drug administration via the human gastrointestinal tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
. This contrasts with parenteral nutrition or drug administration (Greek ''para'', "besides" + ''enteros''), which occurs from routes outside the GI tract, such as intravenous routes. Enteral administration involves the esophagus, stomach, and small and large intestines (i.e., the gastrointestinal tract). Methods of administration include oral, sublingual (dissolving the drug under the tongue), and rectal. Parenteral administration is via a peripheral or central vein. In pharmacology, the route of drug administration is important because it affects drug metabolism, drug clearance, and thus dosage. The term is from Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
''enteros'', "intestine".
Forms
Enteral administration may be divided into three different categories, depending on the entrance point into the GI tract: oral (by mouth), gastric (through thestomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
), and rectal (from the rectum). (Gastric introduction involves the use of a tube through the nasal passage ( NG tube) or a tube in the belly leading directly to the stomach (PEG tube
Percutaneous endoscopic gastrostomy (PEG) is an endoscopic medical procedure in which a tube (PEG tube) is passed into a patient's stomach through the abdominal wall, most commonly to provide a means of feeding when oral intake is not adequate (fo ...
). Rectal administration usually involves rectal suppositories.)
Drug absorption from the intestine
The mechanism for drug absorption from the intestine is for most drugs passive transfer, a few exceptions include levodopa andfluorouracil
Fluorouracil (5-FU), sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pan ...
, which are both absorbed through carrier-mediated transport. For passive transfer to occur, the drug has to diffuse through the lipid cell membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...
of the epithelial cells lining the inside of the intestines. The rate at which this happens is largely determined by two factors: Ionization
Ionization, or Ionisation is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecul ...
and lipid solubility.
Factors influencing gastrointestinal absorption:
* Gastrointestinal motility Gastrointestinal physiology is the branch of human physiology that addresses the physical function of the gastrointestinal (GI) tract. The function of the GI tract is to process ingested food by mechanical and chemical means, extract nutrients and ...
.
* Splanchnic Splanchnic is usually used to describe organs in the abdominal cavity.
It is used when describing:
* Splanchnic tissue
* Splanchnic organs - including the stomach, small intestine, large intestine, pancreas, spleen, liver, and may also include the ...
blood flow.
* Particle
In the physical sciences, a particle (or corpuscule in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass.
They vary greatly in size or quantity, from ...
size and formulation.
* Physicochemical
Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mecha ...
factors.
First pass metabolism
Drugs given by enteral administration may be subjected to significant first pass metabolism, and therefore, the amount of drug entering the systemic circulation following administration may vary significantly for different individuals and drugs. Rectal administration is not subject to extensive first pass metabolism.See also
* Enteric (disambiguation) *Feeding tube
Eating (also known as consuming) is the ingestion of food, typically to provide a heterotrophic organism with energy and to allow for growth. Animals and other heterotrophs must eat in order to survive — carnivores eat other animals, herbi ...
References
{{Dosage forms, state=expanded Routes of administration