Chapter 3
Pharmacokinetics
Pharmacocinétique : Vue d’ensemble
Pharmacokinetics is a scientific discipline that focuses on the journey of a drug within the body, encompassing four key stages: absorption, distribution, ...
Mécanisme d’absorption du médicament : transport membranaire passif
Passive transport is a method of drug absorption where small, lipid-soluble drugs can move across the cell membrane. This movement happens along the ...
Mécanisme d’absorption du médicament : transport membranaire médié par le transporteur
Certain large, lipid-insoluble drug molecules that resemble amino acids, peptides, or glucose, require specialized carrier proteins to facilitate their ...
Absorption des médicaments : facteurs affectant l’absorption gastro-intestinale
The process of oral drug absorption can be influenced by several factors. Weakly acidic drugs tend to be absorbed more readily from the stomach due to ...
Biodisponibilité : Vue d’ensemble
Bioavailability refers to the proportion of an unaltered drug that, after administration, enters the systemic circulation and can be distributed to the ...
Facteurs influençant la biodisponibilité : élimination au premier passage
When a drug is taken orally, it undergoes a journey starting from the gastrointestinal (GI) tract, passing through the portal vein, reaching the liver, ...
Bioéquivalence : Vue d’ensemble
Pharmaceutical equivalents, by definition, are drug products with the same active ingredient in the same quantities, encapsulated in identical dosage ...
Effet de premier passage
Presystemic elimination, or the first-pass effect, is the metabolism of drugs that reduces their effective concentration at the site of action. Apart from ...
Évolution temporelle de l’effet du médicament
The progression of a drug's impact can be analyzed by examining both the concentration-time course and the effect-time course. The concentration-time ...
Distribution du médicament : liaison tissulaire
Upon entering the systemic circulation, drugs can distribute into the interstitial and intracellular fluid of various tissue cells. This distribution is ...
Barrières physiologiques
Physiological barriers are semi-permeable cellular structures restricting drug diffusion into intracellular compartments and tissues. There are six types ...
Distribution du médicament : liaison aux protéines plasmatiques
Drugs predominantly attach to plasma proteins, with only a small percentage remaining unbound. The unbound portion can be calculated as one minus the ...
Modèles à compartiments : Modèle à compartiment unique
The single-compartment model serves as a simplified representation of the human body. This model assumes that the body functions as a single, well-mixed ...
Modèles à compartiments : Modèle à deux compartiments
The two-compartment model divides the body into central and peripheral compartments to account for varying blood perfusion rates among organs and tissues, ...
Distribution des médicaments : Volume de distribution
The volume of distribution refers to the theoretical volume necessary to contain the entire amount of an administered drug at the same concentration ...
Biotransformation médicamenteuse : aperçu
Pharmaceutical substances known as xenobiotics are predominantly lipophilic and nonionized. This enables them to permeate lipid bilayers, such as cell ...
Métabolisme des médicaments : réactions de phase I
A phase I reaction is a biochemical process that introduces a functionally reactive polar group to a substance. This transformation predominantly occurs ...
Métabolisme des médicaments : réactions de phase II
Phase II reactions are essential for the detoxification and elimination of drugs from the body. These reactions involve the conjugation of parent drugs or ...
Élimination du médicament par voie rénale : filtration glomérulaire
The kidney serves as the primary organ responsible for eliminating drugs and their metabolites from the body. This process, known as renal elimination, ...
Élimination du médicament par voie rénale : réabsorption tubulaire
During the process of renal excretion, as the glomerular filtrate progresses to the distal convoluted tubule (DCT), drugs that are highly permeable, ...
Élimination du médicament par voie rénale : sécrétion tubulaire
Once the process of glomerular filtration is completed, blood carrying unfiltered drug molecules traverses through efferent arterioles and makes its way ...
Élimination des médicaments : le concept d’élimination
Drug elimination refers to removing drugs from the body, either through urine by the kidneys or through bile by the liver. Drug clearance is a ...
Élimination médicamenteuse : voies non rénales
The liver plays a pivotal role in eliminating drugs and their metabolites, primarily through a process known as biliary excretion. This process involves ...
Cinétique de l’élimination des médicaments
Eliminating drugs from the body is a vital process that occurs through excretion or metabolism. Understanding the kinetics of drug elimination is crucial ...
Concentration à l’état d’équilibre
A steady state refers to the level of a drug in the body once it has reached an equilibrium between administration and elimination. It represents the ...
Schéma posologique du médicament : aperçu
A drug dosage regimen describes the specific instructions and schedule for administering a drug to a patient. It considers factors such as drug dosage, ...
Schéma posologique rationnel : dose d’entretien et dose de charge
A rational dosage regimen considers a drug's pharmacokinetics, including its absorption, distribution, metabolism, and elimination from the body. By ...
Schéma posologique : Dose fixe
Fixed-dose regimens are a common approach to administer drugs to achieve and maintain desired levels of the drug in the body. In this dosing strategy, a ...
Promédicaments
Prodrugs are a class of pharmaceutical compounds that undergo a biotransformation process within the body to be converted into a pharmacologically active ...
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