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Last edited: 10/21/2022
ANTIANGINAL DRUGS
Antianginal Drugs
Medical Editor: Ana Guerra
OUTLINE
I) PATHOPHYSIOLOGY OF ANGINA
II) BETA BLOCKERS
(A) BETA BLOCKERS TREATMENT
ALOGORITH
III) CALCIUM CHANNEL BLOCKERS
(A) CALCIUM CHANNEL
BLOCKERS TREATMENT
ALGORITHM
IV) NITRATES
(A) NITRATES TREATMENT
ALGORITHM
V) RANOLAZINE
(A) RANOLAZINE TREATMENT
ALGORITHM
VI) REVIEW QUESTIONS
VII) REFERENCES
VIII) ANSWERS TO QUESTIONS
I) PATHOPHYSIOLOGY OF ANGINA
(1) Atherosclerotic plaque or spasms
Occlusion of coronary arteries by atherosclerotic plaques or an spasm
(2) Increased O2 demand by myocardial cells (MVO2)
Because of the poor amount of O2 that myocardial cells are receiving
(i) Stable angina
o Reduction of oxygen supply to the myocardium but
still enough to prevent an infarction.
i. Lasts less than ten minutes
ii. Relieved by nitrates or by
iii. Relieved by exercise
Antianginal Drugs
(ii) Vasospastic angina (AKA Prinzmetal or Variant)
i. At rest
ii. Younger females with history of tobacco
smocking.
iii. Triggered by triptanes, cocaine or alcohol.
iv. Occur more commonly during the morning.
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(iv) Unstable angina
(v) NSTEMI
▪ Ischemia to the myocardium without exertion.
o Release of troponins from the myocardial cells.
o Due to unstable plaques
▪ No need of O2 demand
▪ Severe chest pain
▪ Infarction only affects partially the myocardium
walls.
(vi) STEMI
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II) BETA BLOCKERS
First-line prophylactic medication
(i) Metoprolol
(ii) Atenolol
(iii) Propranolol (beta 1 and beta 2 activity)
(1) Mechanism of action
(2) Adverse effects
1) Inhibition of nodal cells (chronotropic and
dromotropic actions)
▪ Decrease of HR
Bradycardia
Hypotension or shock – Careful with patients with
decompensated heart failure.
Bronchoconstriction when using propranolol for its
effects on Beta 2 receptors.
1) Decrease of contractility
▪ Decrease of stroke volume
• Decrease of cardiac output
Hypoglycemia unawareness
(B) BETA BLOCKERS TREATMENT ALOGORITHM
Patient with angina
(i) Good for patients
(ii) Careful with patients with
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III) CALCIUM CHANNEL BLOCKERS
Second-line prophylactic medication
Preferred in patients with Prinzmetal or vasospastic angina
(1) Mechanism of Action
(i) Non-DHP CCB´s:
o Verapamil
o Diltiazem
1) Inhibition of nodal cells
2) Decrease of contractility
RECALL
RECALL
Within the heart, Non-DHP calcium channels allow Ca++ to
enter into the nodal cells and increase action potential
Within the arterial smooth muscle cells, DHP calcium
channels allow Ca++ to enter into the cells and increase
action potential
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o Verapamil > diltiazem
o DHP CCB > Non-DHP CCB
(ii) DHP CCB´s:
o Amlodipine
o Nifedipine
1) Arterial smooth muscle cells relaxation
2) Reduction of vasospasm on coronary artery
cells
(2) Adverse Effects
Bradycardia
Decrease of contractility
DHP CCB: Reflex tachycardia due to decrease of SVR
Increase risk of mortality in post MI patients
(B) CALCIUM CHANNEL BLOCKERS TREATMENT ALGORITHM
Patient with angina
a. CCB: Either Non-DHP or DHP: Especially
if vasospasm or Prinzmetal; HTN,
COPD or DM
b. Nitrates
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IV) NITRATES
(1) Mechanism of Action
(i) On veins
Tolerance:
Drug enters the venous smooth muscle cell
▪ Stimulation of guanylate cyclase
o Have a nitrate-free interval (10-12 hours)
o Inhibits contraction of the smooth cell
▪ Venodilation → Reduction of
preload → Reduction of CO
• Reduction of O2 demand
(ii) On arteries
Drugs enters the arterial smooth muscle cell
▪ Stimulation of guanylate cyclase
o Inhibits contraction of the smooth cell
▪ Coronary vasodilation → Increase
perfusion to the myocardium
(2) Drugs
(i) Short acting
▪ Sublingual or subdermal
(ii) Long acting
(B) NITRATES TREATMENT ALGORITHM
a. CCB: Either Non-DHP or DHP: Especially if vasospasm or Prinzmetal; HTN, COPD or DM
b. Nitrates: Long acting nitrates (ISDN, ISMN)
▪ More beneficial: Post MI, DM, COPD/ Asthma
▪ CI: HTN
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V) RANOLAZINE
(1) Mechanism of Action
(i) Ischemia without Ranolazine
o Na+ influx into the cell → Increase of Na+/Ca++
contratransporter
(ii) Ischemia with Ranolazine
o Inhibition of inward Na+ channel → No Ca++ influx
into the cell
(2) Adverse Effects
Drug interactions
Prolonged depolarization phase → QT interval → Increase risk of Torsades de Pointes
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(B) RANOLAZINE TREATMENT ALGORITHM
a. CCB: Either Non-DHP or DHP: Especially
if vasospasm or Prinzmetal; HTN,
COPD or DM
b. Nitrates: Long acting nitrates (ISDN,
ISMN)
▪ More beneficial: Post MI, DM, COPD/
Asthma
▪ CI: HTN
▪ Beneficial to patient with arrhythmias
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VI) REVIEW QUESTIONS
3) Sarin is a nerve gas that is an
organophosphate cholinesterase inhibitor.
Which agent could be used as an antidote to
sarin poisoning?
b. Pilocarpine
c. Carbachol
d. Atropine
e. Physostigmine.
4) A patient with asthma was prescribed a β2
agonist for acute relief of bronchospasm, but
did not respond to treatment. Which drug is the
most likely next option for this patient?
a. Benztropine
b. Ipratropium
c. Oxybutynin
d. Physostigmine
5) A 50-year-old male who is noncompliant with
medications was recently diagnosed with
COPD. His physician would like to prescribed
an inhaled anticholinergic that is dosed once or
twice daily. Which drug is most appropriate for
this patient?
a. Atropine
b. Ipratropium
c. Tiotropium
d. Trospium
6) Which is the most effective drug for motion
sickness for a person planning to go on a
cruise?
a. Atropine
b. Fesoterodine
c. Scopolamine
d. Tropicamide
7) Which drug is useful in treating sinus
bradycardia?
a. Atropine
b. Cisatracurium
c. Neostigmine
d. Succinylcholine
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