Chapter 5
Pharmacokinetics: Drug Biotransformation
Chapter 5
Pharmacokinetics: Drug Biotransformation
Drug biotransformation or metabolism entails chemical alteration of xenobiotics, either activating or deactivating their pharmacological properties.
…
Phase I biotransformation or functionalization entails the chemical transformation of drugs into metabolites via oxidative, reductive, and or hydrolytic …
Phase I biotransformation primarily involves microsomal enzymes that catalyze oxidative reactions, using molecular oxygen and NADPH. Notably, only one …
Carbon-nitrogen systems, encompassing aliphatic and alicyclic amines, undergo oxidative reactions.
Secondary and tertiary amines primarily undergo …
Reductive reactions introduce electrons to drug molecules, affecting polar functional groups like hydroxy and amino, allowing subsequent biotransformation …
Hydrolysis is a chemical process where a compound is decomposed by reacting with water without altering its oxidation state.
This process plays a vital …
Conjugation involves the covalent linkage of a conjugating reagent to drugs or their metabolites in the presence of a transferase enzyme.
These reagents …
Glucuronidation, a key phase II biotransformation reaction, involves the conjugation of glucuronic acid to xenobiotics or metabolites.
This process is …
Sulfation, a phase II biotransformation reaction, involves the addition of a polar sulfate group to a drug.
The process is catalyzed by nonmicrosomal …
Glutathione is a tripeptide consisting of three amino acids – glutamic acid, cysteine, and glycine.
It plays a pivotal role in detoxification via …
Acetylation is a crucial phase II biotransformation process involving the addition of an acetyl group to a substrate.
It is similar to α-amino acid …
Phase II methylation reactions involve the attachment of a methyl group to a substrate. This reaction is the reverse of the phase I demethylation. …
Phase II biotransformations primarily involve detoxification processes where xenobiotics conjugate with endogenous substances.
The cyanide ion's …
Drug metabolism can be influenced by a drug's physicochemical properties, like molecular size and shape, which dictate the drug's interaction with …
Drug metabolism varies among species due to distinct enzyme systems and metabolic pathways.
Even within the same species, diverse strains can exhibit …
The liver has numerous functions, including nutrient metabolism. In contrast to other in vitro and in vivo models of liver research, the isolated perfused …
A lack of validated cancer models that recapitulate the tumor microenvironment of solid cancers in vitro remains a significant bottleneck for preclinical …
Finding a long-term, human-relevant culture model for primary human hepatocytes (PHHs) for pharmacological and toxicological studies remains a challenge. …