The purpose of metabolism in the body is usually to change the chemical structure of the substance, to increase the ease with which it can be excreted from the body. Drugs are metabolized through various reactions including: Oxidation. Reduction.
How does metabolism affect drugs?
Most drugs must pass through the liver, which is the primary site for drug metabolism. Once in the liver, enzymes convert prodrugs to active metabolites or convert active drugs to inactive forms.
What is drug metabolism in medicinal chemistry?
Drug metabolism is the chemical alteration of a drug via a biological system to aid its elimination by increasing its hydrophilicity. … Since drug metabolism is mediated by enzymes, there is potential for natural variability and for co-administered drugs to interact, either by enzyme inhibition or induction.
What are the two categories of drug metabolism?
Drug metabolism reactions comprise of two phases: Phase I (functionalization) reactions such as oxidation, hydrolysis; and Phase II (conjugation) reactions such as glucuronidation, sulphate conjugation. Oxidation reactions are the most common and vital. These may occur at carbon, sulfur or nitrogen centre.
What is the importance of cytochrome p450 in drug metabolism?
Knowledge of the most important drugs metabolized by cytochrome P450 enzymes, as well as the most potent inhibiting and inducing drugs, can help minimize the possibility of adverse drug reactions and interactions.
What causes slow drug metabolism?
Underlying health conditions can also influence your drug metabolic rate. Some concerning ones are chronic liver disorders, kidney dysfunction, or advanced heart failure. Drug and Food Interactions. CYP450 enzymes can be impacted by the foods you eat and other drugs you take.
How do drugs break down in the body?
Nucleoside analog drugs are not broken down by the liver but travel through the kidneys where the liver sometimes combines them with other chemicals so they can be dissolved and passed out in the urine. The cytochrome p450 system, a group of enzymes, breaks down drugs before they are metabolized by the liver.
What are the importance and consequences of drug metabolism?
The majority of metabolic processes that involve drugs occur in the liver, as the enzymes that facilitate the reactions are concentrated there. The purpose of metabolism in the body is usually to change the chemical structure of the substance, to increase the ease with which it can be excreted from the body.
What are the four stages of drug metabolization?
The method by which a drug is administered, along with other factors, determines the speed of onset of effects. Drugs undergo four stages within the body: absorption, distribution, metabolism, and excretion.
What is first pass metabolism of drug?
The drug is absorbed from the GI tract and passes via the portal vein into the liver where some drugs are metabolised. Sometimes the result of first pass metabolism means that only a proportion of the drug reaches the circulation. First pass metabolism can occur in the gut and the liver.
What are the sites of drug metabolism?
Most drugs must pass through the liver, which is the primary site for drug metabolism. Once in the liver, enzymes convert prodrugs to active metabolites or convert active drugs to inactive forms. The liver’s primary mechanism for metabolizing drugs is via a specific group of cytochrome P-450 enzymes.
What are the factors affecting metabolism?
Your metabolic rate is influenced by many factors – including age, gender, muscle-to-fat ratio, amount of physical activity and hormone function.
What is meant by drug metabolism?
Drug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems.
What is the meaning of cytochromes?
Cytochrome, any of a group of hemoprotein cell components that, by readily undergoing reduction and oxidation (gain and loss of electrons) with the aid of enzymes, serve a vital function in the transfer of energy within cells. Hemoproteins are proteins linked to a nonprotein, iron-bearing component.
How does cytochrome p450 work?
Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that function as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown.
What are drug substrates?
Definitions. substrates are drugs or other substances (xenobiotics) which are metabolized by cytochrome enzymes including 1. pharmacologically active drugs which require metabolism to inactive form for clearance from the body. metabolically activated drugs (prodrugs) which require conversion to active drug.