PRELIM 02 - Drug Metabolism Flashcards
Drug metabolism is also known as __________
Biotransformation
Process that plays a central role in the elimination of drugs and other foreign compounds (xenobiotics) from the body
Drug metabolism/Biotransformation
The most important organ in drug metabolism
Liver
Most drugs absorbed by the body are __________
Lipophilic
2 categories of drug metabolism reactions (FC)
Phase I (Functionalization reactions), Phase II (Conjugation reactions)
Phase I reactions are also known as __________ reactions
Functionalization
Phase II reactions are also known as __________
Conjugation reaction
Most common reaction under Phase I reaction
Oxidation
Most common reaction under Phase II reaction
Glucuronidation
Oxidation (Phase of drug metabolism)
Phase I (Functionalization)
Reduction (Phase of drug metabolism)
Phase I (Functionalization)
Hydrolysis (Phase of drug metabolism)
Phase I (Functionalization)
Glucuronidation (Phase of drug metabolism)
Phase II (Conjugation)
Sulfation (Phase of drug metabolism)
Phase II (Conjugation)
Glycine conjugation (Phase of drug metabolism)
Phase II (Conjugation)
Glutathione conjugation (Phase of drug metabolism)
Phase II (Conjugation)
Acetylation (Phase of drug metabolism)
Phase II (Conjugation)
Methylation (Phase of drug metabolism)
Phase II (Conjugation)
Involves the introduction of a functional polar group (ex. OH, COOH, NH2, SH) into the xenobiotic molecule to produce a more water-soluble compound (Phase of drug metabolism)
Phase I (Functionalization)
Involves direct introduction of the functional group or by modifying or “unmasking” existing functionalities (Phase of drug metabolism)
Phase I (Functionalization)
Involves the attachment of endogenous compounds to the functional handles of parent compounds to form water-soluble conjugated products (Phase of drug metabolism)
Phase II (Conjugation)
2 processes that terminate or attenuate biological activity (Exceptions in Phase II reactions) (MA)
Methylation, Acetylation
Process that protects the body against chemically reactive compounds or metabolites (Exceptions in Phase II reactions)
Glutathione (GSH) conjugation
Meaning of LUNA
Lipophilic, Unionized, Nonpolar, Absorbed
Meaning of HIPE
Hydrophilic, Ionized, Polar, Excreted
Valence increase (Oxidation or reduction)
Oxidation
Loss of electrons (Oxidation or reduction)
Oxidation
Presence of reducing agent (Oxidation or reduction)
Oxidation
Addition of oxygen (Oxidation or reduction)
Oxidation
Removal of hydrogen (Oxidation or reduction)
Oxidation
Addition of electronegative element (Oxidation or reduction)
Oxidation
Valence decrease (Oxidation or reduction)
Reduction
Gain of electrons (Oxidation or reduction)
Reduction
Presence of oxidizing agent (Oxidation or reduction)
Reduction
Removal of oxygen (Oxidation or reduction)
Reduction
Addition of hydrogen (Oxidation or reduction)
Reduction
Removal of electronegative element (Oxidation or reduction)
Reduction
Major pathway for carboxylic acid derivatives such as amides and esters (Examples of Phase I reactions)
Hydrolysis
Cofactor involved in glucuronidation (an example of Phase II reaction)
Uridine diphosphate glucuronic acid (UDPGA)
Enzyme involved in glucuronidation (an example of Phase II reaction)
UDP glucuronosyltransferase
Cofactor involved in sulfation (an example of Phase II reaction)
Phosphoadenosyl phosphosulfate (PAPS)
Enzyme involved in sulfation (an example of Phase II reaction)
Sulfotransferase
Cofactor involved in glycine conjugation (an example of Phase II reaction)
Glycine
Enzyme involved in glycine conjugation (an example of Phase II reaction)
Acyl-CoA glycinetransferase
Was the first mammalian metabolite discovered from glycine conjugation
Hippuric acid
Cofactor involved in glutathione conjugation (an example of Phase II reaction)
Glutathione (GSH)
Enzyme involved in glutathione conjugation (an example of Phase II reaction)
GSH-S-transferase
3 amino acids that comprises glutathione (GCG)
Glutamate, Cysteine, Glycine
The __________ group in cysteine is responsible for detoxification in glutathione
Thiol (-SH)
Cofactor involved in methylation (an example of Phase II reaction)
S-Adenosylmethionine
Enzyme involved in methylation (an example of Phase II reaction)
Transmethylases/Methyltransferases
Cofactor involved in acetylation (an example of Phase II reaction)
Acetyl-CoA
Enzyme involved in acetylation (an example of Phase II reaction)
N-Acetyltransferase
__________ is not yet fully developed in neonates and children
Glucuronidation
Condition that results from the inability of infants to conjugate chloramphenicol with glucuronic acid
Grey baby syndrome
Grey baby syndrome results from the inability of infants to conjugate __________ with glucuronic acid
Chloramphenicol
Condition that results from the inability of newborns to conjugate bilirubin with glucuronic acid
Kernicterus (Neonatal hyperbilirubinemia)
__________ is the major metabolism route of acetaminophen in children
Sulfation
__________ is the major metabolism route of acetaminophen in adults
Glucuronidation
In __________, sulfation is major and there is a lack of glucuronyltransferase enzymes
Cats
In __________, glucuronidation is major and there is a lack of sulfotransferase enzymes
Pigs
In most animals, conjugation for benzoic acid occurs with __________
Glycine
In birds, conjugation for benzoic acid occurs with __________
Ornithine
___________ involves variation in acetylating ability caused mainly by differences in N-acetyltransferase activity
Acetylation polymorphism
4 drugs that undergo acetylation (HIPS)
Hydralazine, Isoniazid, Procainamide, Sulfonamide
Egyptians, African-Americans, and Caucasians are __________; they tend to accumulate higher drug plasma concentrations, which leads to a greater therapeutic response
Slow acetylators
Eskimos and Asians are __________; they eliminate the drug more rapidly, which leads to an inadequate therapeutic response
Rapid acetylators
__________ accumulate higher blood concentrations of the un-acetylated drug, thus they are more prone to drug-induced toxicities
Slow acetylators
In slow acetylators, hydralazine and procainamide increases their risk of __________
Systemic lupus erythematosus (SLE) syndrome
In slow acetylators, isoniazid increases their risk of __________
Peripheral nerve damage
In slow acetylators, sulfasalazine increases their risk of __________
Hematologic disorders
__________ produces toxic metabolites more rapidly; they are more likely to develop isoniazid-associated hepatitis
Rapid acetylators
__________ is the hepatotoxic metabolite of isoniazid
Acetylhydrazine
Rapid acetylators are more likely to develop __________
Isoniazid-associated hepatitis
Reduction of an aldehyde yields a __________
Primary alcohol
Reduction of a ketone yields a __________
Secondary alcohol
Oxidation of a primary alcohol yields an __________
Aldehyde
Oxidation of a secondary alcohol yields a __________
Ketone
Hydrolysis of an ester yields 1 __________ and 1 __________ (CA)
Carboxylic acid, Alcohol
An __________ is an example of a reducing agent
Antioxidant
Ranking of functional groups according to hydrolysis reactivity (Least to most reactive) (AETAA)
Amide, Ester, Thioester, Acid anhydride, Acid chloride