Drug metabolism Flashcards
BIoactivation of Valacyclovir –>
Valacyclovir to acyclovir by Hydrolysis then acyclovir monophosphate by viral thymidine kinase then to acyclovir triphosphate
Acetaminophen: benzoquinoneimine relation
Toxic metabolite
Cyclophosphamide (CP) and ifosfamide (IF) are widely used antineoplastic agents, but their side-effect of hemorrhagic cystitis (HC) is still encountered as an important problem. ________ is the main molecule that binds with bladder mucus and responsible of this side-effect and ______ is the commonly used preventive agent
Acrolein
mesna (2-mercaptoethane sulfonate)
Active metabolite of spironolactone
Canrenone
How does methanol causes histotoxic hypoxia
Metabolism of methanol, give rise to formic acid. This acid is an inhibitor of the mitochondrial cytochrome OXIDASE causing histotoxic hypoxia
methanol TOXICITY ANTIDOT
Ethanol and fomepizole can be administered to delay methanol metabolism
Ethylene glycol toxicity: mechanism.
oxalic acid formation
ANtidot: Ethanol and fomepizole
The primary location for drug metabolizing enzymes
Endoplasmic reticulum
UDPGT catalyze
glucuronidation
UDPGT present in
Mitochondria & Endoplasmic reticulum
Many water-soluble enzymes presnt in
Cytosol
alcohol dehydrogenase present in
Endoplasmic reticulum
aldehyde dehydrogenase present in
Mitochondria
MAOi presnt in
Mitochondria
GSH present in
Endoplasmic reticulum
Non microsomal enzyme participating in Phase I reaction
reductase, aminase and monoamine oxidase (MAO), alcohol dehydrogenase
What are Conjugation reactions
Glucuronidation, glutathione conjugation, sulfonation, acetylation, glycine conjugation methylation
Bacteria resident in the GI tract are known to be involved in what type of reduction
azo and nitro reductions
Phase I reaction in sulfasalazine and olsalazine
azoreduction
5-aminosalicylic acid (5ASA) and sulfpyridine is the product of
reduction sulfasalazine
General term of enzyme used in conjugation reactions that transfers a high-energy molecule called the cofactor or cosubstrate to the xenobiotic
transferase
Glutathione is tripeptide . what are the peptides?
glycine-cysteine-glutamate
Esters (hydrolysis) produce →
acid + alcohol.
Acyclovir -→ Acyclovir Monophosphate. enzyme involved is
viral thymidine kinase
Amide hydrolysis products -→
acid + amine.
Acetanilide hydroxylation →
acetaminophen.
Acetamininophen → N-Benzylquinoneimine
Glutathione conjugation
N-Benzylquinoneimine ——————— → Mercaptopurine
vitamin C deficiency Decreases ______ pathways
oxidative
Vitamin E deficiency retards ____________
dealkylation and hydroxylation.
Low protein diet decreases _______ drug metabolism
oxidative
