Anti Angina Therapy Flashcards
What are the approaches for treating Angina?
1.Increase coronary Blood flow
2.Reduce Myocardial Oxygen consumption
-reduce HR
-reduce contractility
-decrease ventricular workload
-reduced preload
-reduced afterload
Prevent platelet deposition and aggregation
Which vessels do Nitrates dilate?
Both veins and coronary arteries and systemic arteries decreasing preload and afterload
What does Nitric Oxide do?
Essentially it activates an enzyme called Guanylyl Cyclase which increases cGMP which acts on Protein kinase G which cause SM relaxation
What are the hemodynamic effects of Nitrate administration?
- BP unchanged or slight decrease
- HR unchanged or slight increase
- Pulmonary vascular resistance decreased
- Slight CO reduction
What are the adverse side effects of Nitrates?
Hypotension (higher doses) Reflex tachycardia (may worsen angina) Orthostatic Hypotension Syncope Headache Drug rash
What drugs are absolutely contraindicated with Nitrates?
ED drugs like Sildenafil and other type V PDE inhibitors,
What is the hepatic enzyme responsible for metabolising nitrates
Gluthathione-organic nitrate reductase
What is the major disadvantage of oral administration of nitrates?
Extensive first pass hepatic metabolism
What happens with continuous Nitrate exposure?
Loss of efficacy, Tolerance
How would one counter tolerance?
Have nitrate free periods of the day or take only upon ssymptoms
What happens if nitrates are suddenly interrupted?
Anginal rebound which would lead to coronary Vasospasm
What class of drug would you combine with Dihydropyridine in the treatment of Angina?
A beta-blocker
What drug would you not combine a beta-blocker with in the treatment of Angina?
Non-Dihydropyridine i.e Verapamil and Diltiazem
In which type of Angina do you not use b-blockers?
Vasospastic
