Pharmacology of stable coronary artery

Question 1

drugs can help by

Answer 1

reducing heart rate, reducing myocardial contractility, afterload

Question 2

purpose of drug treatment

Answer 2

relieve symptoms, halt the disease process, regression of disease process, prevent myocardial infarction, prevent death

Question 3

vasodilators

Answer 3

calcium channel blockers, nitrates- oral and sublingual

Question 4

rate limiting drugs

Answer 4

beta adrenoceptor antagonists, calcium channel blockers, ivabradine

Question 5

common beta blockers used

Answer 5

bisoprolol, atenolol

Question 6

beta blockers

Answer 6

reversible antagonists of the B1 and B2 receptors, newer drugs are cardioselective acting primarily on the B1 receptors, block the sympathetic system

Question 7

beta blockers decrease what three determinants of myocardial oxygen demand

Answer 7

heart rate, contractility, systolic wall tension and also allow improved perfusion of the subendocardium by increasing diastolic perfusion time. this increases the exercise threshold at which angina occurs

Question 8

contraindications of beta blockers

Answer 8

asthma, peripheral vascular disease (relative contraindication), raynauds syndrome, heart failure (those patients who are dependent on sympathetic drive), existing bradycardia/ heart block

Question 9

adverse drug reactions of beta blockers

Answer 9

tiredness/ fatigue, lethargy, impotence, bradychardia, bronchospasm, rebound- sudden cessation of beta blocker therapy may precipitate myocardial infarction

Question 10

drug- drug interactions

Answer 10

primarily pharmacodynamic

Question 11

what happens when beta blockers with verapamil or diltiazem

Answer 11

bradycardia or cardiac failure

Question 12

what happens when beta blockers with insulin or oral hypoglycaemics

Answer 12

exaggerate and mask hypoglycaemic actions

Question 13

what happens when beta blockers with other hypotensive drugs

Answer 13

hypotension

Question 14

examples of calcium channel blockers

Answer 14

diltiazem, verapamil, amlodipine

Question 15

calcium channel blockers

Answer 15

prevent calcium influx into myocytes and smooth muscle lining arteries and arterioles by blocking the L type calcium channel

Question 16

rate limiting calcium channel blockers

Answer 16

CCBs like diltiazem and verapamil reduce heart rate and force of contraction

Question 17

vasodilators calcium channel blockers

Answer 17

CCBs like amlodipine reduce BP and after load

Question 18

why never use nifedipine immediate release

Answer 18

may precipitate acute MI or stroke

Question 19

post MI CCB use

Answer 19

may increase morbidity and mortality in patients with impaired LV function

Question 20

unstable angina CCB use

Answer 20

evidence that dihydropyridines may increase infarction rate and death in the unstable patient

Question 21

adverse drug reactions CCBs

Answer 21

ankle oedema, headache, flushing, palpitation

Question 22

nitrovasodilators examples

Answer 22

glyceryl trinitrate GTN, isosorbide mononitrate, isosorbide dinitrate

Question 23

how do nitrovasodilators work

Answer 23

relax almost all smooth muscle by releasing NO which then stimulates the production of cGMP which produces smooth muscle relaxation. reduce preload and after load so reduce myocardial oxygen consumption

Question 24

how do nitrovasodilators relieve angina

Answer 24

arteriolar dilatation and so reducing cardiac after load and thus myocardial work and oxygen demand. peripheral venodilatation and so reducing venous return, cardiac preload and thus myocardial workload

Question 25

tolerance of nitrate therapy is overcome by

Answer 25

giving asymmetric doses of nitrate 8am and 2pm which incorporates a nitrate free period

Question 26

adverse reactions to nitrates

Answer 26

headache- increase dose slowly, hypotension- GTN syncope

Question 27

second line therapy for angina

Answer 27

nicorandil, ivabradine, ranolazine

Question 28

nicorandil

Answer 28

significant effect. activates ATP sensitive potassium channels allowing entry of potassium into cardiac myocytes and inhibiting calcium influx and so has a negative isotropic action. induces relaxation of vascular smooth muscle and has coronary vasodilator properties

Question 29

ivabradine

Answer 29

selective sinus node If channel inhibitor, inhibits the If pacemaker current in the sinoatrial node and reduces heart rate. decreases heart rate means decreases myocardial oxygen demand . used for the symptomatic treatment of chronic stable angina in adults with normal sinus rhythm and heart rate greater than 70bpm. reduces myocardial infarction

Question 30

ranolazine

Answer 30

inhibits persistent or late inward sodium current in heart muscle, this leads to reduction in intracellular calcium levels this results in reduced heart wall tension and reduced oxygen requirements

Question 31

do not use ranolazine with

Answer 31

clarithromycin, erythromycin or ketoconazole because these antibiotics and antifungal significantly inhibit CYP3A4

Question 32

antiplatelet therapy

Answer 32

combined with aspirin or P2Y12 inhibitors results in a significant reduction in serious vascular events, non fatal myocardial infarction, non fatal stroke and vascular mortality

Question 33

anti platelet agents eg aspirin

Answer 33

prevent the formation of platelet aggregates which are important in the pathogenesis of angina, unstable angina and acute MI. aspirin is a potent inhibitor of platelet thromboxane production which stimulates platelet aggregation

Question 34

P2Y12 inhibitors block what

Answer 34

platelet P2Y receptor which plays a key role in platelet activation and the amplification of arterial thrombus formation

Question 35

cholesterol lowering agents examples

Answer 35

HMG CoA reductase inhibitors -atorvastatin, simvastatin