Drug Therapy Of Ischemic Heart Disease

Question 1

Compare ECG of classic & priznmetal anginal

Answer 1

C, ST depression

P, ST elevation with oaradixical T wave normalization

Question 2

What is the direct cause of anginal pain?

Answer 2

By accumulation of metabolites in cardiac muscle

Question 3

The distinguishing feature of unstable angina from MI is

Answer 3

No in serum markers in angina

Question 4

Describe mechanism of action of nitrates

Answer 4

Nitrates bind to certain receptors on vessel wall, they release nitric oxide which bind with -SH group forming S-nitrosothiol that activates guanyl cyclase inc cGMP, dec IC Ca++, resulting SM relaxation.

Question 5

Describe pharmacological actions of nitrates

Answer 5

1. Relaxation of vascular SM, venodilators (dec preload) & arteriodilators (dec afterload)
2. Brief relaxation of other smooth musces (GIT: Sphincter of Oddi & cardiac opening of oesophagus)

Question 6

Describe mechanism of antianginal effect of nitrates

Answer 6

Dec O2 demand: venodilators & arteriodilators (in high doses) causing dec preload & afterload
Inc O2 supply: VD of large epicardial vessels & collateral & redistribution of blood to ischemic areas by dec VR, dec ventricular filling & dec coronary art compression in subendocardium (by pooling of blood in splanchnic area & extermities
Antiplatelet effect

Question 7

Mention indications of nitrates

Answer 7

All types of angina
Congestive HF & acute pulmonary edema
Hypertensive emergencies
Acute MI (dec size)

Question 8

Mention adverse effects of nitrates

Answer 8

1. Throbbing headache+ flushing
2. Withdrawal angina
3. Postural hypotension
4. Reflex tachycardia in high dose
5. Methemoglobenemia
6. Rapid tolerance

Question 9

GR: Occurrence if throbbing headache with nitrates &ttt

Answer 9

Due to VD of meningeal arteries ttt aspirin

Question 10

GR: Occurrence if reflex tachycardia with nitrates &ttt

Answer 10

Due to dec BP leads to worse angina ttt BB

Question 11

GR: Occurrence if rapid tolerance with nitrates &ttt

Answer 11

Due to -SH group depletion & VC caused by activation of adrenegic system by RAAS
Nitrate free interval 8hrs/d

Question 12

GR: Occurrence if Methemogobinemia with nitrates &ttt

Answer 12

More with nitrites due to oxidation

Methylene blue

Question 13

Mention contraindications of nitrates

Answer 13

1. With sildenafil
2. HOCM
3. RT vent innfarction
4. In volume depletion & severe aortic stenosis (cautiously)

Question 14

With nitrates a maximum of …. Is taken within …., if no effect ….

Answer 14

3 tablets
15 min
Refer ti hospital

Question 15

GR: NG & ISDN are not given oral

Answer 15

Extensive 1st pass metabolism

Question 16

Mention preparations of NG & ISDN & their indications

Answer 16

1. Subligual/spray: 1st choice in acute attack & immediate prphylaxis
2. Transdermal patch/oral slow release: for CHF & long term prophyalxis
3. IV: AHF or unstable angina

Question 17

What is the difference between ISDN & ISMN

Answer 17

With ISMN

No 2st pass metabolism, high bioavailability, delayed onset & longer action.

Question 18

Mechanism of antianginal effect of BB

Answer 18

Dec O2 demand: ded HR, BP, lipolysis & fat utilization
Inc O2 supply by inc coronary filling in diatole (by dec HR), Redistribution of coronary blood flow to subendocardial ischemic areas
Antiplatelet activity

Question 19

All BB are effective except ….

Answer 19

BB with ISA may inc HR

Question 20

Role of BB in Long term prophylaxis of IHD

Answer 20

Dec frequency & severity of attacks
Control HR at rest
Blunt inc HR & BP during exercise

Question 21

Describe mechanism of action of CCBs

Answer 21

They act on alpha1 subunit of L-type Ca channel in conductive tissue, cardiac myocytes & vascular SM including coronaries.

Question 22

Mention a short & a long-acting DHP CCB

Answer 22

S, nifedipine

L, amlodipine

Question 23

Describe selectivity of DHPs & nonDHPs

Answer 23

DHP, Vessels>myocardium>SAN&AVN

NonDHP, SAN&AVN>myocardium=vessels

Question 24

Mention vascukar effects of CCBs

Answer 24

Peripheral arteriolar VD, dec PR & ABP

Mora with DHP

Question 25

Compare cardiac effects of DHP & non DHP

Answer 25

DHP, No effects on nodes, reflex tachycardia (more with short-acting) & mild inhibition of contractility. Non-DHP, dec SAN & AVN conduction, bradycardia & suppress contractility

Question 26

Verapamil is more ….. than diltiazem

Answer 26

Cardio-depressant

Question 27

Mention other actions of CCBs

Answer 27

Relaxation of Git, bronchial, urinary, uterine SM | Inhibit platelet aggregation

Question 28

Compare adverse effects of DHP & nonDHP

Answer 28

``` DHP, Reflex tachycardia…worsen angina Hypotenion….flushing & headache Ankle edema,dizziness & tinnitus Non-DHP, Bradycardia & heart block Hypotension, heart failure Constipation (verapamil) ```

Question 29

Mention therapeutic uses of CCBs

Answer 29

Angina (of choice in vasospastic) diltiazem & long acting DHP Hypertension Supraventricular arrhythmia (verapamil): PSVT & AF & Af HOCM (Verapamil)

Question 30

Describe antianginal effect of CCBs

Answer 30

Dec O2 demand by ive ino & chronotropic effect (more with verapamil), dec peripheral resistance (more with DHP) Inc coronary blood flow due to diltation of epicardial coronary vessels

Question 31

Mention other uses of CCBs

Answer 31

Peripheral vascular disaese, prevention of premature labour, migraine prophylaxis

Question 32

Describe mechansim & precautions of trimetazidine

Answer 32

It switches myocardial metabolism from fatty acid oxidation (more O2 demand to glucose oxidation, so dec demand. Given in combination with other antianginal drugs. Reduce dose by 50% in renal impairment CI parkiaonism

Question 33

Describe mechanism, indications & precautions of ivaradine

Answer 33

Selectively inhibits pacemaker I-funny current leading to dec cardiac pacemaker activity & dec HR Indicated, systolic HF & IHD CI with CCBs (inhibit their metabolism) used cautiously with BB

Question 34

Drugs dec atheroscelerosis & MI risk

Answer 34

Antiplatelet Hypolipedmic agents Anticoagulants

Question 35

Management of ACS

Answer 35

``` Antiplatlet Anticoagulant ACEI Antianginal Statins Fibrinolytics (within 6 hr) ```

Question 36

Revascularization and angioplasty may be needed EXCEPT in

Answer 36

Vasospastic angina

Question 37

Describe mechanism, indications & side effects of ranolazine

Answer 37

Inhibits late phase of Na current, dec Na & Ca overload, improve diasoltic function & improve O2 supply & demand balance Used in chronic angina Side effect, prolong QT interval, drug interactions (extensively metabolised by CYP3A4)