Pharm Cards For Chapter 4: Drug Metabolism

Front 1

What are foreign chemical compounds in the air, water, and food that a person is exposed to?

Back 1

Xenobiotics

Front 2

Is an important mechanism by which the body terminates the actions of some drugs, while activating other pro drubs

Back 2

Biotransformation

Front 3

Phase 1 reactions include what?

Back 3

Oxidation (especially by the CP450 enzymes), reduction, deamination, and hydrolysis

Front 4

Cytochrome P450 enzymes are found in high concentrations where?

Back 4

the smooth endoplasmic reticulum of the liver.

Front 5

75% of drugs metabolized by CP450 enzymes are by which two enzymes?

Back 5

CYP3A4 and CYP2D6

Front 6

Phase II reactions involve what?

Back 6

conjugation or addition of subgroups OH, NH2, and SH to the drug molecule

Front 7

What are properties of the subgroups used to conjugate drugs that aid in drug metabolism?

Back 7

they are relatively polar and less lipid soluble, enabling them to be excreted by the kidney

Front 8

First pass metabolism of EtOH is greater in which gender?

Back 8

Men

Front 9

What bad habit, other than alcohol consumption, is a common inducer of CYP450 enzymes, leading to increased drug metabolism.

Back 9

smoking

Front 10

Which ester is metabolized by a phase 1 reaction involving plasma cholinesterase? (normally very rapid)

Back 10

Succinylcholine

Front 11

An abnormal form of cholinesterase, seen in 1 in 2500 people, that leads to very slow metabolism of their target drubgs, can cause what?

Back 11

neuromuscular paralysis caused by succinylcholine lasts many hours instead of 5 minutes

Front 12

People who are slow acetylators and are deficient in their acetylation capacity have a difficult time metabolizing which drugs?

Back 12

Isoniazid, hydralazine, and procainamide. these drugs are metabolized by phase II N-acetylation

Front 13

What percentage of the white and african american population are slow acetylators?

Back 13

50%, is inherited as an autosomal recessive gene

Front 14

What are the most common inducers of CYP 450 enzymes, and therefore increased metabolism?

Back 14

Carbamazapine, Phenobarbital, Phenytoin, and Rifampin

Front 15

What are the most common inhibitors of CYP 450 enzymes, and therefore decreased metabolism?

Back 15

Cimetidine, Amiodarone, Furanocoumarins (grapefruit juice), Azole antifungals, and Ritanovir

Front 16

What are the common suicide inhibitors of metabolizing enzymes?

Back 16

ethinyl estradiol, norethindrone, spironolactone, secobarbital, allopurinol, fluroxine, and propylthiouracil

Front 17

What drug can cause inhibition of metabolism by reducing hepatic blood flow?

Back 17

Propanolol

Front 18

What glycoprotein serves as a modulator of intestinal drug transport, usually expels drugs from the intestinal mucosa into the lumen? (presystemic elimination)

Back 18

MDR-1 also known as P-gp
(P-glycoprotein). Is also found in the BBB and resistant cancer cells.

Front 19

P-gp inhibitors given with certain drugs may cause what?

Back 19

toxic plasma concentrations of the drug at normal doses.

Front 20

Name three P-gp inhibiting drugs:

Back 20

CCB's verapamil, mibefradil, and furanocoumarin components of grapefruit juice

Front 21

3 drugs normally expelled by P-gp, and are therefore more toxic when combined with P-gp inhibitors:

Back 21

Digoxin, Cyclosporin, and Saquinavir

Front 22

Toxic metabolite intermediate of acetaminpohin, formed with overdose.

Back 22

N-acetyl-p-benzoquinoneimine

Front 23

Antidote for Acetaminophen poisoning

Back 23

N-acetylcystiene. allows for formation of more glutathione, thereby metabolizing toxic intermediate

Front 24

What commonly abused substance can predispose to acetaminophen toxicity by increasing phase 1 metabolism, leading to more toxic metabolite formation

Back 24

Ethanol, predisposes to phase II because increased alcohol metabolism by the MEOS pathway, induces CYP450 enxymes, which are phase II