PHARMACOKINETICS 3 Flashcards
(30 cards)
Include oxidation (especially by the cytochrome P45- group of enzymes also called mixed function oxidases), reduction, deamination and hydrolysis
Phase 1 metabolism
Refers to the loss of electrons, and an increase in oxidation state
Oxidation
Involves cytochrome P-450 mixed oxidase system
CYP-mediated
Refers to the addition of electrons and a decrease of oxidation state
Reduction
It involves splitting of large molecule involving water as solvent
Hydrolysis
Synthetic reactions that involve addition (conjugation) of subgroups to -OH, -NH 2, and -SH functions on the drug molecule.
Phase 2 Metabolism
(T/F) Phase 2 Metabolism convert the Phase I metabolites to more polar and water-soluble
products
True
The condensation of the drug or its primary metabolite with d-glucoronic acid
GLUCURONIDATION
(T/F) The human newborn is still not capable of sulfate conjugation
False (Capable)
It is the most common endogenous amine for conjugation with organic acids.
Glycine
(T/F) A newborn is not capable of acetylation.
True
It is only a minor pathway for conjugating drugs and xenobiotics
METHYLATION
Parts of Phase 1 Metabolism
Oxidation
Reduction
Hydrolysis
Phase II: GLUCORONIC ACID CONJUGATION Enzyme
GLUCORONOSYL TRANSFERASE
Phase II: SULFATE CONJUGATION Enzyme
SULFOTRANSFERASES
Phase II: GLUTATHIONE CONJUGATION Enzyme
GLUTATHIONE-S-TRANSFERASE
Phase II: ACETYLATION Enzyme
N-ACETYL TRANSFERASES
Phase II: METHYLATION Enzyme
METHYL TRANSFERASE
Phase II: Amino Acid Conjugation Enzyme
COENZYME A
(T/F) Alteration in the enzyme activity in liver microsomes resulting in a faster rate of metabolism
True
A drug that stimulates its own metabolism
AUTO-INDUCTION (Phenobarbital)
Induction where one enzyme inducer stimulate the rate of metabolism of another drug
FOREIGN-INDUCTION
May be due to substrate competition or due to direct inhibition of drug metabolizing enzyme
ENZYME INHIBITION
The final elimination of the drug substance
Excretion