5 - Drug metabolism

Question 1

True or false?

Metabolism of prodrugs activates their pharmacological activity.
Xenobiotic metabolism only occurs in the liver
Hydrolysis is a Phase 1 reaction
Cytochrome P450 uses NADH+ as cofactor
Cytochrome P450 contains Cu2+ at its active site

Answer 1

TRUE - Metabolism of prodrugs activates their pharmacological activity.
FALSE - Xenobiotic metabolism only occurs in the liver
TRUE - Hydrolysis is a Phase 1 reaction
TRUE - Cytochrome P450 CAN use NADH+ as cofactor but generally uses NADPH+
FALSE - Cytochrome P450 contains Cu2+ at its active site

Question 2

True or false?

Metabolism of lipophilic chemicals facilitates their excretion
Metabolism of drugs prior to entering the systemic circulation is known as “first pass metabolism.”
Phase 2 metabolism includes reduction and acetylation.
Phase 2 metabolism generally increases the polarity of drugs.
Conjugation of drugs with glutathione is the most common Phase 2 route of metabolism.

Answer 2

TRUE - Metabolism of lipophilic chemicals facilitates their excretion
TRUE - Metabolism of drugs prior to entering the systemic circulation is known as “first pass metabolism.”
FALSE - Phase 2 metabolism includes reduction (phase1) and acetylation.
TRUE - Phase 2 metabolism generally increases the polarity of drugs.
FALSE - Conjugation of drugs with glutathione is the most common Phase 2 route of metabolism. (glucoronidation is most common)