Drugs for Ischaemic Heart Disease Flashcards
Name the 3 types / effects of anti-anginal drugs
- Vasodilation
- Cardiac depression
- Cardiac pacemaker retardation
Name the 4 classes of drugs to treat angina
- Nitrates
- Calcium channel blockers
- Beta blockers
- Ivabradine
*antiplatelets and cholesterol lowering drugs can also be used
MOA of nitrates
Source of NO which activates guanylyl cyclase which increases conversion of GTP to cGMP.
Increased cGMP leads to increased deactivation of myosin LC thus increases vasorelaxation
Outline how nitrate induced vasorelaxation leads to anti-angina effect
Vasorelaxation constitutes both venodilation and arteriolar dilation
Venodilation: results in decreased preload
Arteriolar dilation: results in decreased after load
Both will decrease oxygen consumption, thus is a therapy for angina
State 2 common nitrates
- Nitroglycerin (glyceryl trinitrate)
- Isosorbide dinitrate (ISDN)
State the 2 routes of administration for nitroglycerin
- Sublingual
- Transdermal
Advantage of sublingual administration of nitroglycerin
Absorbed very quickly so faster onset of action and duration of action
Clinical use of nitroglycerin
Acute treatment for angina pectoris
Mode of administration for ISDN / ISMN
Oral
Clinical use of ISDN / ISMN
Angina pectoris prophylaxis
Can also be used for heart failure
Besides reducing preload and afterload, ISDN / ISMN also has an additional effect on the coronary arteries.
What is the effect and what’s the result of it?
Additional direct dilatory effect on the coronary arteries
Results in decreased intramural pressure, which improves subendocardial blood flow
3 ADRs of nitrates
- Reflex tachycardia
- Hypotension
- Headache
Physiological basis for reflex tachycardia in nitrate use
Vasorelaxation causing baroreceptor reflex
Physiological basis for hypotension in nitrate use
Vasorelaxation causing venodilation
Physiological basis for headache in nitrate use
Vasorelaxation causing meningeal artery vasodilation