Drug metabolism involves the biochemical modification of drugs, primarily through enzymatic processes, to facilitate their excretion from the body.
A) Biotransformation
Drugs can undergo transformation through various pathways, resulting in:
Inactive Compounds: Metabolites ready for excretion.
Active Metabolites: Compounds with their own therapeutic or toxic effects.
Prodrugs: Inactive forms that become active only after metabolic conversion.
B) Metabolic Pathways
Cytochrome P450 Enzymes
A key family of enzymes involved in drug metabolism. Individual variability in these enzymes can significantly influence drug response.
Phase I Reactions
Involve oxidation, reduction, or hydrolysis to increase polarity of the compound, preparing it for further modification or excretion.
Phase II Reactions
Conjugation of Phase I metabolites with larger molecules (e.g., glucuronic acid), making them more water-soluble for easier excretion.
C) Metabolite Profiling in Drug Metabolism
Techniques such as mass spectrometry help in identifying and quantifying drug metabolites, aiding in the prediction of potential drug interactions and side effects.
Drug metabolism is crucial in determining a drug’s duration of action, potential interactions, and side effects, all of which influence therapeutic effectiveness and safety.