4.2 - Anti-Anginal Drugs Flashcards
What are the three classes of anti-anginal drugs?
–> Nitrates
–> Beta-blockers
–> (Voltage-sensitive) Calcium Channel Blockers
What are nitrates?
Drugs derived from nitroglycerin - a volatile and explosive compound used in the manufacturing process and dynamite
In pharmaceutical preparations, these chemical have been stabalized
Nitroglycerin:
–> Tmax / T1/2
–> Metabolism
Tmax: 30 seconds
T1/2: 2 mins
Significant first pass hepatic effect
Isosorbide mononitrate:
Tmax/ T1/2?
Route?
Tmax: 1 hr
T1/2: 45 mins
Route is p.o.
What is the route of nitroglycerin administration?
Sublingual (Tablet or aerosol)
Transdermal
–> Be aware of tolerance
Topical ointment
I.v
oral
–> Extensive first pass hepatic betabolism
What is the mechanism of action of nitrates?
Vasodilation of:
Veins
–> Decreased venous return; Decreased preload
Arterioles
–> Drop in BP; decreased resistance and decreased afterload
Coronaries
–> Increased coronary bloodflow
What are some adverse effects of nitrates?
–> Orthostatic hypotension (w reflex tachycardia at high doses)
–> Frequent headaches, especially at the beginning of treatment
–> Tachyphylaxis (tolerance) when continuously exposed to drug
What does chronotropic mean?
Related to heart rate
What does inotropic mean?
Related to force of heart contraction
What does dromotropic effect mean?
Related to conduction velocity in the heart
How do beta blockers affect the heart?
They demonstrate negative chronotropic, inotropic, and dromotropic effects on the heart.
How do beta blockers effect the kidneys?
They decrease renin release by juxtaglomerular cells
–> Less AngII, therefore lower BP.
How do beta blockers treat angina?
Decrease heart rate and contractility = therefore decrease in oxygen consumption by the heart
Decrease in afterload d/t decreased blood pressure.
Which beta blockers are cardio-selective? What does this mean?
Metoprolol, bisoprolol, atenolol, acebutolol
–> Acts mostly on beta 1 (Cardiac)
Why would you use a non-specific beta blocker like propranolol?
It is very lipid soluble
–> Allows it to cross cell membranes and have access to the brain, it is therefore used for anxiety and migraines
What does ISA (intrinsic sympathomimetic activity) mean?
In blocking, they also have agonist activity
–> Such as when we want to protect the tissue form overactivation but don’t want a complete blockage
Which cardioselective beta blocker has Intrinsic sympathomimetic activity (ISA)?
Acebutolol
Which non-cardioselective beta blocker has Intrinsic sympathomimetic activity (ISA)?
pindolol
What are the therapeutic effects of beta blockers?
Treatment of:
–> Angina, hypertension, arrythmias, heart failures
–> Migraines, anxiety (lipid soluble)
–> Hyperthyroidism
What are the three sub-classes of calcium channel blockers?
Dihydropyridines
Non-dihydropyridines
–> Benzothiazepines
–> Phenylalkylamines
What are the dihydropyridines?
Amlodipine, nifedipine
Name a benzothiazepine.
Diltiazem
Name a phenylalkylamine
Verapamil
Which calcium channel blockers have vascular effects? What are they?
Amlodipine, Nifedipine, verapamil, diltiazem
–> Arterial vasodilation (decrease in BP, afterload)
–> Coronary artery vasodilation/reduction of vasospasms
Which calcium channel blockers have cardiac effects?
The non-dihydropyridines (diltiazem, verapamil)
–> Negative inotropic effect (decreased force of contraction)
–> Decreased heart rate
What are the adverse effects of calcium channel blockers?
–> Headaches
–> Flushing
–> Edema in lower limbs
–> Orthostatic hypotension
–> Constipation (verapamil)
What are the therapeutic effects uses of calcium channel blockers?
Treatment of:
–> Angina
–> HTN (Amlodipine, Diltiazem, Nifedipine)
–> Arrythmias (non dihydropyridines - Diltiazem, Verapamil)
