Neuro-Biotransformations Flashcards Preview

Pharmacology Class > Neuro-Biotransformations > Flashcards

Flashcards in Neuro-Biotransformations Deck (23):
1

What is Biotransformation

Enzyme driven process of converting one chemical into another

2

What are xenobiotics

Foreign substances within the body

3

What is the first pass effect

The process of oral drugs being absorbed in the small intestine and transported to the liver via the portal system, where they undergo metabolism.

4

What is the result of the first pass system on amount of dosage of a drug that is required

It causes the need for more of a drug to have the same effect as something that may be administered IV

5

What occurs during Phase 1 of Metabolism and what is the general result

Substrate is oxidized, reduced, or hydrolyzed causing the inactivation, but can become highly reactive and toxic

6

What occurs during phase 2 of metabolism and what is the general result

Substrate is conjugated in order to increase molecular weight and water solubility for excretion

7

Is phase 1 catabolic or anabolic

Catabolic

8

Is phase 2 catabolic or anabolic

Anabolic

9

What are the enzymes generally used during phase 1 of metabolism

-CYP450
-Flavin containing monooxygenases (FMO)
-Epoxide hydrolases (mEH,sEH)

10

Where are the enzymes used in phase 1 of metabolism located

Lipophilic ER membranes of the liver

11

What are the characteristics of the drug conjugated seen in phase 2 of metabolism

Polar molecules (water soluble) with high molecular weights

12

Which phase of metabolism occurs at a faster rate

Phase 2

13

Where does phase 2 take place

In the liver

14

Which CYP is most commonly utilized in clearing drugs

CYP3A4

15

Which electron transporter is most commonly used in CYPs

Oxygen and NADPH (one oxygen to drug and one to byproduct water)

16

What is the result of a genetic defect in pseudocholinesterase

Pts can metabolize succinylcholine at only 50% the normal rate

17

What is the result of an autosomal recessive trait resulting in a decrease in the functional N-Acetyltransferases

Metabolizes amines such as caffeine, hydralazine, isoniazid at a much slower rate, leading to hepatitis

18

Which drugs can not be given to patients with a low level of N-Acetyltransferase

-caffeine
-isoniazid
-hydralazine

19

What are some well documented inducers of CYP450

-Ethanol
-phenytoin
-benzo[a]pyrene
-rifampin
-phenobarbital
-barbiturates

20

Ingestion of grape fruit juice causes what effect on which CYP

Irreversible binding to CYP3A4, leading to inhibition

21

In a patient with gout, which drugs have to be regulated

Allopurinol (inhibits xanthine oxidase) can not be given with mercaptopurine

22

What is the method that excessive acetopmetaphin can lead to hepatotoxicity

Normally, on 5% is eliminated via the glutathione. In high level of excess, more is used, depleting the stores and causing damage

23

What is an example of a drug that does not follow the general order of phase metabolism

Isoniazid