How a Pill Accomplishes its Mission in the Body-ADME

Drugs enter the body through the four processes of absorption, distribution, metabolism, and excretion, but the four processes of different administration routes have their own advantages. Today we talk about the most common oral drug absorption and metabolism processes in the digestive tract.

After oral administration of the drug in the gastrointestinal tract, it enters the liver from the portal vein and is first enzymatically hydrolyzed by the digestive juice and mucous membranes in the gastrointestinal tract and the enzymes in the liver. The effective amount of drug entering the systemic blood circulation is reduced, resulting in a decrease in the efficacy of the drug. Some drugs “casualty” or even more than half, this phenomenon is called “first pass effect”. For example, oral insulin is inactivated by proteolysis.

From this point of view, oral medications are often destroyed before they are officially on the battlefield (often systemic blood circulation and diseased organs and tissues). In professional terms, the oral bioavailability of this drug is relatively low. In order to counteract the metabolic effects of liver drug enzymes, some drugs will also double the first dose to increase bioavailability.
Drugs enter the body through the four processes of absorption, distribution, metabolism, and excretion, but the four processes of different administration routes have their own advantages. Today we talk about the most common oral drug absorption and metabolism processes in the digestive tract.

After oral administration of the drug in the gastrointestinal tract, it enters the liver from the portal vein and is first enzymatically hydrolyzed by the digestive juice and mucous membranes in the gastrointestinal tract and the enzymes in the liver. The effective amount of drug entering the systemic blood circulation is reduced, resulting in a decrease in the efficacy of the drug. Some drugs “casualty” or even more than half, this phenomenon is called “first pass effect”. For example, oral insulin is inactivated by proteolysis.

From this point of view, oral medications are often destroyed before they are officially on the battlefield (often systemic blood circulation and diseased organs and tissues). In professional terms, the oral bioavailability of this drug is relatively low. In order to counteract the metabolic effects of liver drug enzymes, some drugs will also double the first dose to increase bioavailability.
Because of this, emergency medicines are often administered by intravenous injection, and do not need to go through the steps of disintegration, dissolution, and absorption of oral medicines, and directly enter the blood circulation. Among all the methods of administration, the medicine is the fastest, but it is relatively dangerous. The sex is also higher.

Certain drugs can also be administered by anal enema (the pros and cons were discussed a few days ago, and interested friends can tuition by themselves) or suppositories. Due to the small contact surface, the amount of absorption is less than that of oral administration, but due to the lack of absorption route In the liver, the drug damages less and acts faster.