Angina Flashcards
Cause of angina
IMBALANCE BETWEEN MYOCARDIAL OXYGEN SUPPLY AND
DEMAND
Risk Factors
1- Hypertension.
2- diabetes mellitus
3- smoking
4- sex male: female 4:1
5-obesity
Antianginal drugs
1.Nitrates
2. β receptor blockers
3. Ca chennel blockers
4. Other drugs as k channel openers
5. New drugs
Source
synthetic
Chemistry
Organic Nitrates use
Inorganic nitrates (inactive)
Organic Nitrites not commonly use
Inorganic nitrites not use
Why organic nitrites not use?
cause
methemoglobinemia
Absorption
1- oral 90% in first pass metabolism only 10% use
2- sub-lingual
3- I.v
4-inhalation
Distribution
Pass B.B.B
• Mechanism of action:
• Nitrate is “de-nitrated” by glutathione
-S-transferase which requires sulfhydryl
group leading to release of “Nitric Oxide”
(N.O.) which stimulates guanylyl cyclase
enzyme and increases synthesis of c-GMP which in turn leads to smooth
muscle relaxation particularly blood vessel
Action vasodilation mainly in
Veins > arteries
On veins decrease
Preload
On artery decrease
After load
Coronary artery
Profusion and distribution so increase blood flow
Other arteries
Headache
Flush
Increase I.O.P
Decrease blood pressure
To avoid hypotension we use with nitrates
Beta blockers to control tachycardia reflex
