elementary drug metabolism

Question 1

drug metabolism

Answer 1

enzymatic conversion of the drug to another chemical entity

Question 2

what is the msot important drug metabolising organ

Answer 2

liver

Question 3

what other organs also ocntribute

Answer 3

kidney gut mucosa and lungs and skin

Question 4

when is bioavailabilty reduced

Answer 4

when administered orally

Question 5

bioavailability

Answer 5

amount of drug that eventually reaches systemic circulation of an administered dose of the drug
quantity reaching systemic circulation /quantity adminsitered

Question 6

where doe the phases of metabolism occur

Answer 6

in the liver

Question 7

where are hepatic drug metabolizing enzymes

Answer 7

embedded in smooth endoplasmic reticulum of the liver hepatocytes

Question 8

which cross plasma membrane to be metabolised more readily

Answer 8

non polar as can cross membrane more readily

Question 9

phase 1 metaboism

Answer 9

change in the drug by oxidation reduction or hydrolysis to form a chemically reactive metabolite that can be active/ toxic

Question 10

what is the oxidation phase accomplished by

Answer 10

cytphcrome p450 enzymes

Question 11

what occurs during the oxidation phase

Answer 11

drug molecule incorporates one atom of 02 to the drug to form a hydroxyl group

Question 12

role of cytoplasmic enzymes

Answer 12

can metabolise the durg

Question 13

what are susceptible to hyrolysis

Answer 13

ester and amide bonds

Question 14

what can phase 1 produce

Answer 14

harmful metabolites during oxidation

Question 15

what are cytochrome p450 enzymes

Answer 15

membrane bound haem proteins

Question 16

genetics of p450

Answer 16

some poeple lack such acitity leading to higher drug plasma levels
some have higher leading to lower plasma levels.. reduced drug action

Question 17

phase 2 reaction

Answer 17

involve the combination of the dryg with one of the several polar molecules to form a water soluble metabolite; conjugation

Question 18

what terminates all biological acitvty

Answer 18

phase 2 reactions

Question 19

conjugated produces

Answer 19

can be readily excreted via kidney

Question 20

can some drugs go directly to phase 2

Answer 20

yes