Significance of First Pass Metabolism

First-pass metabolism is the initial metabolism of a drug, primarily in the liver, before it reaches systemic circulation. This process reduces the drug's bioavailability, affecting its effectiveness. Various administration routes, such as intravenous, transdermal, topical, nasal, buccal, intra-vesical, rectal, and fast-dissolving tablets, bypass first-pass metabolism to enhance drug bioavailability and therapeutic effects. Understanding and avoiding this metabolism is crucial in drug delivery and efficacy.

Synonyms: First-pass elimination, First-pass effect, Hepatic metabolism, Pre-systemic metabolism, Presystemic metabolism, Hepatic clearance, Metabolic inactivation, Bioavailability reduction

The below excerpts are indicatory and do represent direct quotations or translations. It is your responsibility to fact check each reference.

Hindu concept of 'First Pass Metabolism'
Hinduism Books

In Hinduism, First Pass Metabolism describes the liver's metabolism of a drug, reducing its bioavailability before it reaches systemic circulation. This process can be bypassed through alternative administration methods like scalp, rectal, nasal, or transdermal routes, enhancing drug efficacy.

Significance in Ayurveda (science of life):
Ayurveda Books

Ayurveda is a branch of Indian science dealing with medicine, herbalism, taxology, anatomy, surgery, alchemy and related topics. Traditional practice of Ayurveda in ancient India dates back to at least the first millenium BC. Literature is commonly written in Sanskrit using various poetic metres.

From: Journal of Ayurvedic and Herbal Medicine

(1) The metabolism of a drug by the liver before it reaches systemic circulation, which the nasal route avoids.[1]

From: International Research Journal of Ayurveda and Yoga

(1) Lozenges avoids this, also useful for patients having dysphagia.[2]

From: Journal of Ayurveda and Integrated Medical Sciences

(1) When the drug is administered through the scalp, the first-pass metabolism can be avoided as it allows the drug to be absorbed directly into the systemic circulation.[3] (2) This is the process by which the liver metabolizes a drug before it reaches systemic circulation, and rectal administration bypasses a portion of this.[4] (3) First pass metabolism is a metabolic process that can be avoided with intra-vesical drug delivery, which can enhance the therapeutic effect of a drug.[5] (4) A metabolic process that can be avoided by using transdermal drug delivery, which enhances the bioavailability of the drug and reduces peaks and troughs in drug levels.[6] (5) Vasti bypasses this in the liver, which leads to faster systemic effects, making it a unique form of drug administration.[7]

The concept of First Pass Metabolism in scientific sources
Science Books

First-pass metabolism is the reduction of a drug's concentration, primarily in the liver, before it reaches systemic circulation, decreasing bioavailability. This is often bypassed through alternative delivery methods.

Significance in Health Sciences:
Health Sciences Books

From: International Journal of Pharmacology

(1) After oral intake chlormadinone acetate is rapidly absorbed and undergoes nearly no of this.[8] (2) First-pass metabolism is one of the physiological factors that can reduce the bioavailability of orally administered drugs.[9] (3) The initial metabolism of a drug in the liver before it reaches the systemic circulation, which can limit the effectiveness of orally administered medications.[10]

From: Asian Journal of Pharmaceutics

(1) The absolute bioavailability of oral nisoldipine tablets is only 5.5% because of this.[11] (2) Intestinal lymphatic transport has the potential to enhance bioavailability through avoidance of first-pass metabolism in enterocytes as well as the liver.[12] (3) This process reduces the bioavailability of a drug, requiring higher or more frequent doses.[13]

From: South African Family Practice

(1) This phrase refers to the process where a drug is metabolized in the liver before it reaches the rest of the body, which can affect its effectiveness.[14]

From: The Malaysian Journal of Medical Sciences

(1) The hepatic metabolism of a drug before it reaches systemic circulation, relevant in understanding the pharmacokinetics of theophylline.[15]

Significance in Scientific journals, articles, etc.:

This section includes scientific research in the field of healthcare, often involving traditional medicine systems such as Ayurveda, Unani, Siddha and Holistic health. It includes papers from scientific journals classified as either original, clinical or experimental research, review articles or case reports.

From: International Journal of Pharmacology

(1) First-pass metabolism is a process where orally administered buspirone is rapidly absorbed but undergoes metabolism, resulting in a low bioavailability.[16] (2) The process where a compound undergoes extensive metabolism, significantly reducing its oral bioavailability, as observed with felodipine.[17] (3) The process by which flutamide is rapidly metabolized to 2-hydroxyflutamide in the liver after oral administration.[18]

Significance in Environmental Sciences:
Environmental Sciences Books

From: International Journal of Environmental Research and Public Health (MDPI)

(1) First-pass metabolism (FPM) of alcohol occurs in digestive organs like the stomach, small intestine, and liver before systemic circulation, and ADH 3 might be important here due to its very high K m for ethanol.[19] (2) It refers to the initial processing of a substance by the liver and intestines, which can reduce its concentration before it reaches systemic circulation.[20]