Antihypertensives Flashcards
(50 cards)
What is the medical definition of hypertension?
High blood pressure (BP) >130/80 mmHg.
Why is hypertension dangerous?
It can damage vital organs like the brain (stroke), heart (heart disease), kidneys, and retina.
What is primary (essential) hypertension and how is it managed?
Hypertension with no known cause, accounting for 90% of cases.
Antihypertensive agents.
What is secondary hypertension and how can it be treated?
Hypertension caused by renal or endocrine disorders, accounting for 10% of cases.
By addressing the underlying cause.
What is malignant hypertension, its risk, and how is it treated?
A severe, rapidly progressing form of hypertension.
It can lead to retinal or renal damage.
With aggressive medical intervention.
How does relaxation of vascular smooth muscle affect blood pressure?
It reduces peripheral resistance, leading to vasodilation.
How does reducing sympathetic activity lower blood pressure?
Decreased epinephrine (EPI) and norepinephrine (NE) reduce vasoconstriction and heart rate.
How do changes in sodium and water balance lower blood pressure?
Decreasing sodium retention lowers blood volume, reducing blood pressure.
What is the site of action for Clonidine?
CNS (Vasomotor Center).
How does Clonidine reduce sympathetic activity?
It stimulates α2 receptors, reducing NE and EPI release, leading to decreased blood pressure.
What is the site of action for Mecamylamine?
Sympathetic Ganglia.
How does Prazosin lower blood pressure?
It causes vasodilation by blocking α1 receptors, reducing peripheral resistance.
What is the mechanism of Mecamylamine?
Blocks nicotinic receptors, preventing sympathetic transmission to the heart and vessels.
What is the result of Mecamylamine’s action?
Decreased cardiac output and vasodilation.
What receptor does Prazosin block?
α1 receptors on blood vessels.
What are the two types of beta blockers?
Specific β1 blockers and Non-Specific β1/β2 blockers.
Where do specific β1 blockers act?
Heart and kidney (juxtaglomerular cells).
How do specific β1 blockers reduce blood pressure?
By decreasing heart rate, contractility, and renin release.
Why are β1-selective blockers preferred for asthmatics and diabetics?
They lack β2 effects, avoiding bronchoconstriction and worsening peripheral vascular disease.
What additional effect do non-specific β1/β2 blockers have?
They can cause bronchoconstriction due to β2 blockade.
What is the unique feature of beta blockers with ISA?
They have partial agonist activity, causing less cardiac depression.
When are beta blockers with ISA preferred?
In patients with bradyarrhythmias or diminished cardiac reserve.
Where does Hydralazine, Minoxidil, and Sodium Nitroprusside act?
Vascular smooth muscle.
How does Hydralazine cause vasodilation?
It decreases intracellular Ca++ release from the sarcoplasmic reticulum.
