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Flashcards in Pharm principles random Deck (26):
1

Irreversible Comp. inhibitors effect on Km

Unchanged

2

Pharmacokinetics vs Pharmacodynamics

PK - what body does to drug
PD - what drug does to body

3

Vd =

amount of drug in body / plasma drug concentration

4

Decreased protein binding of drug...

Increases Vd (less trapped in plasma)

5

Clearance (CL) =

rate of elimination of drug / plasma drug concentration
= Vd x Ke (elimination constant)

6

t(1/2) =

0.693 x Vd / CL

7

Half-lives vs. SS%

1 - 50%
2 - 25%
3 - 12.5%
3.3 - 10%
4 - 6.25%

8

Loading does =

Cp x Vd / F

9

Maintenance dose =

Cp x CL x dosage interval (time b/t dose) / F

10

Does time to SS change with DOSE or DOSING FREQ?

NO (but concentration at SS may change)

11

Intramuscular or subcutaneous have greater absorption rate?

Intramuscular - d/t high vascularity

12

Zero order elimination drugs?

Phenytoin, Ethanol, Aspirin (high concentrations)

13

Weak acids and OD Rx

Phenobarbital, methotrexate, aspirin, TCAs
(Rx Bicarbonate)

14

Weak bases and OD Rx

Amphetamines
(Rx ammonium chloride, VitC/Cranberry juice)

15

Phase 1 metabolism

@ ER: reduction, oxidation, hydrolysis w/ cytochrome P-450

16

Phase 2 metabolism

@ cytosol: conjugation (Glucuronidation, Acetylation, Sulfation)

17

Location of CYP450 drug metabolism

Liver AND Gut

18

Therapeutic index =

Median toxic dose (TD50) / Median effective dose (ED50)

19

Low TI Drugs

Digoxin, Lithium, Theophylline, Warfarin

20

High TI indicates...

Selectivity

21

Jimson Weed (Datura)

Atropine-like (gardener's pupil)

22

Atropine flush

High dose antimuscarinic causes cutaneous VD (unknown mechanism)

23

Tetrodotoxin

bind fast voltage-gated Na+ channels in cardiac and nerve tissue (blocks AP w/out changing RMP)

24

Ciguatoxin

Opens Na channels causing depolarization
- Temp-related dysesthesia

25

Scombroid

Bacterial histidine decarboxylase converts histidine to histamine (not degraded by cooking)

26

Saxitoxin

From dinoflagellates in "red tide"
- VG-Na channel blocker