Toxic Metabolites in Drug and Contaminant Metabolism

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What is the term for the process where orally administered drugs pass through the liver before entering the systemic circulation?

First-pass effect (correct)

Extrahepatic metabolism

Xenobiotic metabolism

Intestinal metabolism

Which enzyme found in the liver plays a significant role in the metabolism of drugs that pass through it?

CYP3A4 (correct)

P-glycoprotein

Amylase

Acetylcholinesterase

In the context of drug metabolism, what does 'bioavailability' refer to?

The binding of drug molecules to receptors

The fraction of unchanged drug reaching systemic circulation (correct)

The rate of drug excretion from the body

The concentration of drug at the site of action

Which term describes drug metabolism that occurs outside of the liver?

Intestinal metabolism Signup and view all the answers

What is one significant consequence of extensive first-pass metabolism for orally administered drugs?

Decreased oral bioavailability Signup and view all the answers

Which process can sometimes result in decreased oral bioavailability of certain drugs in humans?

First-pass effect Signup and view all the answers

Which of the following is true about the role of intestinal enzymes in drug metabolism?

Intestinal -glucuronidase enzymes can liberate free drugs for possible reabsorption. Signup and view all the answers

In extrahepatic drug metabolism, which tissue has some metabolizing capability but carries out more substrate-selective transformations?

Kidney Signup and view all the answers

Which process involves the reduction of many aromatic azo and nitro drugs by intestinal microbes?

Reduction Signup and view all the answers

How does the first-pass effect impact drug metabolism?

It can lead to significant drug metabolism before reaching systemic circulation. Signup and view all the answers

Which enzyme is particularly important in carrying out hydrolysis of many ester prodrugs in the intestine?

-Lipase Signup and view all the answers

Among the listed drugs, which one undergoes significant sulfate conjugation in the intestinal wall after oral administration?

Isoproterenol Signup and view all the answers

What is the chemically reactive metabolite responsible for liver damage due to bromobenzene administration in rats?

4-bromobenzene oxide Signup and view all the answers

Which environmental contaminants can result in the formation of polycyclic aromatic hydrocarbons?

Refuse burning and industrial processes Signup and view all the answers

What is the stable epoxide metabolite of the anticonvulsant drug carbamazepine, which contributes to its therapeutic effect?

Carbamazepine-10,11-epoxide Signup and view all the answers

Which urinary metabolites result from the nucleophilic attack of GSH on the intermediate epoxide of styrene in rats?

Isomeric mercapturic acid derivatives Signup and view all the answers

In drug metabolism, what process involves covalent binding of styrene oxide to rat liver microsomal proteins and nucleic acids?

Extrahepatic metabolism Signup and view all the answers

Which metabolite is an important urinary metabolite in humans resulting from the hydration of carbamazepine-10,11-epoxide?

10,11-dihydroxycarbamazepine Signup and view all the answers