CARDIOVASCULAR PHARMACOLOGY Flashcards
(51 cards)
What is the role of the Renin Angiotensin Aldosterone System (RAAS) in cardiovascular disease?
It is significant in the aetiology of hypertension and heart failure.
RAAS contributes to the pathophysiology of cardiovascular conditions by regulating blood pressure and fluid balance.
What are the two main classes of drugs discussed in the lecture?
ACE Inhibitors (ACE Is) and Angiotensin Receptor Blockers (ARBs).
Examples include enalapril for ACE Is and candesartan for ARBs.
What is Angiotensin I and its biological activity?
Angiotensin I is inactive and formed from angiotensinogen, with low biological activity.
How is Angiotensin II formed and what is its significance?
Angiotensin II is formed from Angiotensin I by Angiotensin Converting Enzyme (ACE) and is a powerful vasoconstrictor.
List the pathological effects of Angiotensin II
- Promotion of Na+ retention
- Collagen deposition
- Vasoconstriction
- Stimulation of ADH secretion
- Release of aldosterone from adrenal cortex
What is the mechanism of action of ACE Inhibitors?
They inhibit ACE, decreasing Ang II levels, increasing bradykinin levels, and reducing aldosterone release.
What are the pharmacokinetics of Enalapril?
- Route: per oral
- Bioavailability: ~40 - 60%
- Clearance: Renal route
- Peak plasma levels: ~4h
- Plasma T ½: 11 - 14h
What are the cardiovascular indications for ACE Inhibitors?
- Hypertension
- Chronic heart failure
- Renal injury
What are common adverse effects of ACE Inhibitors?
- Initial hypotension
- Cough
- Angioedema
- Renal issues in renal failure
What is the mechanism of action of Angiotensin Receptor Blockers (ARBs)?
They block AT1 receptors, inhibiting all AT1 R mediated effects regardless of Ang II production method.
List the pharmacokinetics of Candesartan.
- Route: per oral as candesartan cilexetil
- Bioavailability: 15 - 40%
- Peak plasma levels: ~3 - 4h
- Plasma T ½: ~9h
What are the cardiovascular indications for ARBs?
- Hypertension
- Congestive heart failure
- Renal injury
True or False: ARBs have a major effect on bradykinin levels.
False
Fill in the blank: The enzyme responsible for converting angiotensinogen to angiotensin I is _______.
Renin
What stimulates the release of renin?
- Sympathetic stimulation of renal β1 adrenergic receptors
- Low Na+ concentration in distal tubule
- Low renal blood pressure
What are the two types of Angiotensin Converting Enzyme (ACE)?
- Extrinsic ACE
- Intrinsic ACE
What effects does Angiotensin II have on the body?
- Powerful vasoconstrictor
- Promotes Na+ and fluid retention
- Enhances sympathetic activity
- Stimulates cardiac and vascular hypertrophy
What is the significance of the AT2 receptor?
It is considered beneficial as it inhibits cell proliferation and promotes vasodilation.
What is the function of aldosterone in the RAAS?
It increases the reabsorption of Na+ and water in the kidneys.
How do ACE inhibitors affect bradykinin levels?
They increase bradykinin levels by preventing its breakdown.
What are the potential adverse drug reactions of ARBs?
They are similar to ACE inhibitors but have fewer bradykinin-related adverse events.
What is 1st pass metabolism?
The process by which the concentration of a drug is significantly reduced before it reaches systemic circulation.
How does hepatic impairment affect enalaprilat formation?
It affects enalaprilat formation but not clearance.
What effect does renal impairment have on enalaprilat?
It reduces clearance resulting in raised plasma concentrations of enalaprilat.
