Cardio

Question 1

Ca Blockers

Answer 1

Amlodipine, nomodipine, nifedipine (dyhidropurine)

Diltiazem, verapimil (non-dihydropuridine)

Block voltage gated L-type Ca channels of cardiac and smooth muscle, reduce contractility
Vascular SM- amlodipine and nifedipine
Cardiac- Verapamil

amlodipine and nifedipine- HTN, angina (including prinzmetal), raynaud, isolated systolic HTN
non-dihydropuridine- HTN, angina, A fib
Nimodipine- subarachnoid hemorrhage

can all cause AV block, edema, hyperprolactinemia, constipation

Question 2

Hydralazine

Answer 2

increase cGMP, smooth muscle relaxation
mostly vasodilates arterioles (dec. afterload)
Severe HTN, HTN in pregnancy (w/ mdopa)
give w/ b blocker for reflex tachy
can cause lupus-like syndrome

Question 3

Nitroprusside

Answer 3

HTN emergency
releases NO to increase cGMP
can cause cyanide toxicity

Question 4

Fenoldopram

Answer 4

D1 receptor agonist
coronary, peripheral, renal, splanchnic dilation
decrease BP and increase natriuresis

Question 5

Nitroglycerine and isosorbide dinitrate

Answer 5

increase cGMP
dilate veins more than ateries (dec. preload) (main way reduces pain in angina)
reflex tachy, monday disease in industrial work
lose tolerance over weekend

Question 6

Statins

Answer 6

inhibit HMG-CoA to mevalonate

hepatotoxic, rhabdomyolysis (especially w fibrates and niacin)

Question 7

niacin

Answer 7

decrease LDL and increase HDL
inhibits peripheral lypolysis and VLDL synthesis
Flushed face (give aspirin)
hyperglycemia (acanthosis nigricans)
hyperuricemia (exacerbates gout)

Question 8

Bile acid resins

Answer 8

Cholestyramine, colestipol, colesevelam
prevents reabsorbion of bile salts
people hate it
decreased fat soluble vitamins
cholesterol gallstones

Question 9

Ezetimbe

Answer 9

blocks cholesterol abs at brush border

causes DIARRHEA

Question 10

Fibrates

Answer 10

Gemfibrozil, clofibrate, bezafibrate
Lowers TGs
upregulates LPL (TG clearance) and activates PPAR-a to induce HDL synthesis a bit
myositis (esp w/ statins)
Cholesterol gallstones (esp w/ bile acid resins)
hepatotoxicity

Question 11

Digoxin

Answer 11

cardiac glycoside
Direct inhibition of Na/KATPase secondarily blocks Na/Ca antiport. More intracellular Ca increases inotropy. stimulates vagus nerve to decrease HR
Use in CHF and A fib (decreased conduction at AV node
ECG- inc PR, dec QT, ST scooping, T inversion
can lead to hypokalemia which is bad
cholinergic- N/V, blurry vision
renal failure decreses excretion
hypokalemia is permissive for dig binding at K binding site
verapamil, amiodarone and quinidine decreases clearance and displaces from tissue binding sites

Question 12

Class 1 antiarrhythmics in general

Answer 12

Na channel blockers
slow or block conduction especially in depolarized cells
decrease phase 0 slope
increase threshold for abnormally firing pacemaker cells

Question 13

Class 1a antiarrhythmics

Answer 13

Disopyramide, quinidine, procainamide
increases AP duration, QT and ERP
use in both atrial and ventricular arrhythmias especially reentrant and ectopic SVT
quinidine- headache and tinnitis
procainamide- SLE like
disopyramide- HF
all thrombocytopenia and torsades de point due to increased QT

Question 14

Class 1b antiarrhythmics

Answer 14

Lidocaine, mexiletine
decreases AP duration
preferentially affects ischemic and depolarized
acute ventricular arrhythmias (esp post MI) and digitalis induced arrhythmias
can cause CN and cardiac depression

Question 15

Class 1c antiarrhythmics

Answer 15

flecainide, propafenone
Significantly prolongs refractory period in AV node, minimal effect on AP duration
SVTs and LAST RESORT in refractory VT
proarrhythmic post MI (contraindicated in structural and ischemic heart disease)

Question 16

Class 2 antiarrhythmics

Answer 16

B blockers
Decrease SA and AV nodal activity by decreases cAMP and Ca
suppresses abnormal pacemakers by decreasing slope of phase 4
AV node particularly sensitive, increases PR
esmolol very short acting
use in SVT to slow ventricular rate
can cause impotence, exacerbate asthma, mask hypoglycemia
metropolol- dyslipidemia
propanolol- exacerbate prinzmetal vasospasm
dont give to cocaine users (a agonist spike)

Question 17

Class 3 antiarrhythmics

Answer 17

K channel blockers
Amiodarone, ibutilide, dofetilide, sotalol (AIDS)
increases AP duration, ERP, QT
use when other antiarrhythmics fail
a fib, A and S for V tach
Sotalol- torsades de pointes, high B blockade
ibutilide- torsades de pointes
amiodarone- pulm fibrosis, hepatotoxic, thyroids, blue/grey corneal and skin deposits, photodermatitis and neurologic effects
Test PFT, LFT, TFT when using amiodarone

Question 18

Class 4 antiarrhythmics

Answer 18

Ca channel blockers
Verapimil and diltiazem
decreases conduction velocity and increases ERP and PR
Prevent nodal arrhythmias and rate control Afib
constipation and flushing

Question 19

Adenosine

Answer 19

Increase K out of cells, hyperpolarizing and decreasing intracellular calcium
drug of choice in diagnosing/abolishing SVT
very short, can cause chest pain. flushing
blocked by theophylline and caffeine
vasodilates coronary arteries, can result in coronary steal
used in imaging to mimic vasodilation seen in exercise

Question 20

Mg2+

Answer 20

effective in torsades de pointes and digitoxin toxicity