ischemia3

Question 1

what is the half life of nitroglycerin

Answer 1

1-3 minutes

Question 2

what are the two active metabolites of nitroglycerin

Answer 2

glyceryl 1, 2-dinitrate

glyceryl 1, 3-dinitrate

Question 3

what is the active metabolite of isosorbide dinitrate (ISDN)?

Answer 3

isosorbide-5-mononitrate (ISMN)

Question 4

why is isosorbide 5-mononitrate preferred

Answer 4

4 hour half life

Question 5

what nitrates are used for angina prevention

Answer 5

ISDN and ISMN

not NTG

Question 6

how would you counsel a patient taking both NTG and sildinafil

Answer 6

48 hours before taking nitrates with Cialis

others 24 hours before taking nitrate

Question 7

what dosing form is best for a patient with chest pain at night

Answer 7

transdermal NTG

drug free in afternoon

Question 8

what is preferred ISMN or ISDN?

why (4 reasons)?

Answer 8

ISMN
longer half life
almost completely absorbed
less rebound angina
greater efficacy

Question 9

what type of Ca channel is in vascular smooth muscle?

what is it’s rate like?

Answer 9

voltage gated L-type Ca channels

slow rate

Question 10

what is calcium entering a vascular smooth muscle’s effect on MLCK

Answer 10

phosphorylation

Question 11

what are the 3 main mechanisms of contraction of vascular tissue?
which is the main one CCB’s inhibit?

Answer 11

1. voltage sensitive Ca channels open in response to depolarization
2. agonist induced release of calcium from SR
3. receptor mediated entry of calcium
   #1=CCBs

Question 12

what has an inhibitory effect in cardiac cells

Answer 12

troponin

Question 13

what stops troponin’s effect in cardiac cells

Answer 13

calcium binding (stops inhibition)

Question 14

what effect do CCBs have on cardiac cells

Answer 14

negative inotropic effect

Question 15

the negative ionotropic effect of dihydropyridines is caused by what?

Answer 15

peripheral dilation leading to baroreceptor reflex

Question 16

what is CCB’s effect on force of contration

Answer 16

decrease it

Question 17

what is another term for inotropic effect on the heart

Answer 17

force of contraction

Question 18

dihyropyridines peripheral dilation causes an increase in what?
what can this effect overcome?

Answer 18

increase SNS tone

can overcome negative inotropic effects on heart (why non-dihydro are better for myocardial ischemia)

Question 19

what is significantly effected by nondihydropyridines

Answer 19

SA and AV nodes

Question 20

what rate is not changed from dihydropyridines

Answer 20

does not change rate of recovery from Ca inhibition

Question 21

what decreases rate of recovery from inhibition in cardiac cells

Answer 21

nondihydropyridines

Question 22

what CCBs show use/ frequency dependance

Answer 22

nondihydropyridines

Question 23

list the two nondihydropyridines

Answer 23

verapamil

diltiazem

Question 24

all CCB’s have what effect

Answer 24

vasodilation

Question 25

arrange these drugs in order of ability to increase blood supply (coronary blood flow): diltiazem, verapamil, dihydropyridines

Answer 25

dihydropyridines> verapamil > Diltiazem

Question 26

what CCBs increase coronary blood flow the most

Answer 26

dihydropyridines

Question 27

what are dihydropyridines effects on BP? what does this lead to?

Answer 27

decrease BP leading to:sympathetic reflexes | SNS reflexes cause increased HR and FOC

Question 28

what CCBs have most potent inotropic effects

Answer 28

verapamil

Question 29

CCB's have little effect on what related to blood flow

Answer 29

venous tone (so A > V)

Question 30

what are some adverse effects of CCBs

Answer 30

1. edema 2. GERD 3. Urine retention 4. Rash 5. increased LFT's

Question 31

what causes edema with CCB's

Answer 31

precapillary dilation and postcapillary constriction

Question 32

what are 3 adverse effects common with verapamil

Answer 32

1. constipation 2. bradycardia 3. HF exacerbation

Question 33

why is urinary retention common with CCBs?

Answer 33

detrusor muscle can't contract as well (can't squeeze pee out)

Question 34

why is GERD common with CCBs?

Answer 34

esophageal sphincter doesn't fully contract

Question 35

why is IR nifedipine not used much

Answer 35

extreme tachycardia can cause MI (too abrupt vasodilation)

Question 36

nifedipine has what unique adverse effect

Answer 36

gingival hyperplasia

Question 37

why do verapamil and diltiazem cause bradycardia?

Answer 37

decreases FOC