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Flashcards in Drugs for Angina Deck (20)
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1
Q

what is angina?

what 3 reasons can give rise to angina?

A

lack of blood to the myocardium

  1. Coronary occlusion
  2. Vasospastic/Variant angina
  3. Unstable angina (platelet aggregation)
2
Q

what is classical angina?

when do symptoms occur?

A
  • the coronary artery is narrowed.
  • with increased emotional or physical exertion
    *
3
Q

What is Variant angina or Prinzmetal’s angina?

when do symptoms occur?

A
  • Results from a reversible spasm of large coronary arteries, usually at the site of atherosclerotic plaque
  • occur at rest or irrespective of the amount of physical or emotional exertion
4
Q

what is Acute coronary syndrome/Unstable angina?

when do you see symptoms?

A
  • increased frequency and severity, as result of combination of atherosclerotic plaques and vasopasm.
  • can occur even at rest. It might signal an impeding myocardial infarction and treated as a medical emergency
5
Q

What are the therapeutic strategies for treatment of angina? Mention the drugs utilized for each strategy.

A
  1. increasing oxygen delivery - Nitrates & Calcium channel blockers
  2. reducing oxygen requirement - Beta adrenergic blockers
  3. Antiplatelet drugs - Low dose aspirin, abciximab
  4. increase the efficiency of oxygen utilization by partial fatty acid oxidation inhibitors - Ranolazine
6
Q

what is preload?

what is afterload?

A
  • amount of blood returning to the heart at the end of diastole
  • the resistance against which the heart has to pump the blood during systole.
7
Q

what drugs are nitrates?

What are they?

how do they work?

do they cause muscle relaxation?

what determines their effectiveness?

A
  • Nitroglycerine (GTN)
  • Isosorbide dinitrate
  • Isosorbide mononitrate
  • they are powerful vasodilators
  • they release Nitric oxide
  • dont cause muscle relaxation
  • Action on capacitance vessels to reduce cardiac pre-load
8
Q

nitrates have what bioavailability?

what is the mode of action of nitrates?

A

low bioavailability

it activates cGMP leading to smooth muscle relaxation

9
Q

which of the nitrate drugs is most commonly used?

what happens when the previous drug is given orally vs. sublingually?

A

Glyceryl trinitrate

orally = low bioavailability (very metabilized by liver)

sublingually = high bioavailability

10
Q

what is the effect of nitrates in the heart?

what other use, other than angina, are nitrates used for?

what will nitrate toxicity cause?

A

more decreased preload than decreased afterload

cyanide poisoning

  • Severe headache
  • Postural hypotension and reflex tachycardia
  • Methemoglobinemia- caused by nitrites, not nitrates`
11
Q

nitrates will interact with which other?

Why?

A

sildenafil (viagra); because it inhibit a phosphodiesterase isoform (PDE5) that metabolizes cGMP in smooth muscle .

12
Q

what is the purpose of CCB in angina?

what are the CCB drugs for angina?

which of these drugs has a greater ratio of vascular smooth muscle effects than cardiac effects?

A
  • to block voltage-gated L-type calcium channels in cardiac and smooth muscle.
    1. Dihydropyridines(DHP): Nifedipine, amlodipine, nicardipine, nimodipine
    2. Verapamil, diltiazem
  • Dihydropyridines
13
Q

nimodipine is used for what other than angina?

Verapamil, diltiazem are used for what type of angina?

A

subarachnoid hemorrhage

block calcium-dependent conduction in the atrioventricular (AV) node and is used to treat AV nodal arrhythmias

14
Q

use of CCB’s in angina looks to produce what effect on the heart?

A

Decreased Preload + Decreased Afterload

(leads to decrease in oxygen demand and increase in oxygen supply)

15
Q

what is nifedipine?

what are the adverse effects of using this?

A
  • mostly an arteriolar vasodilator and has minimal effect on cardiac conduction or HR
  • flushing, headache, hypotension, peripheral edema
16
Q

What is the effect of verapamil?

what drug interaction does it have?

A
  • Slows cardiac conduction, Decreases HR and O2 demand,Causes negative inotropic effect than nifedipine
  • with digoxin, it will increase its levels
17
Q

what does Diltiazem do?

when is it used?

A
  • Slows cardiac conduction, Decreases HR and O2 demand, Causes negative inotropic effect
  • Particularly useful in variant angina
18
Q

What are the adverse reactions of CCB’s?

A
  1. hypotension due to the vasodilatation
  2. Peripheral edema
  3. Over dose leads to cardiac arrest, bradycardia, atrioventricular block, and heart failure.
19
Q

how do beta blockers work in angina?

what is the effect in the heart?

when is it contraindicated?

They are mostly used for what?

A
  • act by opposing the action of adrenaline on the heart because they block the β1 receptors present in the heart
  • decrease heart rate, blood pressure, and contractility (decrease myocardial oxygen requirements)
  • Vasospastic angina
  • Effective in preventing exercise induced angina
20
Q

what is Ranolazine?

Primary mechanism of therapeutic action of ranolazine?

A
  • pFOX inhibitor or partial fatty acid oxidation inhibitor in myocardium
  • reduced contractility. This action results from blockade of a late sodium current