I learnt something new today and thought it might be useful for us to know.
Products administered through oral route will not be found 100% in the bloodstream because 1) absorption by the gut is not 100% due to various factors; and 2) once absorbed they will first pass through the liver where part of the products is destroyed before they get into the bloodstream. This is known as “first-pass metabolism”.
First-pass metabolism refers to any loss of the administered material by transmucosal or hepatic means after absorption and before reaching the systemic circulation.
So for the oral medication that we take, sometimes only 30% is absorbed by the body. This is why the dosage has been adjusted to counter this loss due to the first-pass metabolism.
Administration via subcutaneous is always equal to 100% absorption as the product enters the body without the need to be absorbed from the outside, like in the gut (oral route) or on the skin (transdermal). Subcutaneous, intramuscular and intravenous injections are collectively called parenteral administration (“par-enteral” means outside the gut). This form of administration is used as the gold standard to measure against administration via oral (or enteral) route or via topical (on the skin) route.
The difference in the above 3 parenteral routes is simply the speed which the product will enter the bloodstream from the site of administration. Intravenous is immediate, intramuscular is around 3 – 20 minutes depending on the carrier used to transport the product, and subcutaneous is around 10 – 60 minutes depending on the carrier used to transport the product. All parenteral administrations bypass the liver which is the organ par excellence in destroying (detoxifying) foreign compounds so that they can be safely secreted by the kidneys.
This is why for the Furosemide injection, I was advised to do it subcutaneously and the medication worked after about 30-40 minutes. Now, I’m administering Cow Mau’s RetroMAD1 as subcutaneous injections. As such, I only need to do it twice daily, 12 hours apart. The medication will be in the system after 10 minutes.
The post Administrations of medicines via the oral route and injections appeared first on AnimalCare.
More Articles By AnimalCare
|
| 
Member Login
