Classes of antihypertensives Flashcards
What class of drugs alters sodium and water balance
Diuretics
What class of drugs alters sympathetic function
CNS-acting sympathoplegic, adrenergic neuron blockers, adrenoreceptor antagonists
T/F: Calcium channel blockers cause vasoconstriction
False: Calcium channel blockers cause vasodilation
What two classes of drugs cause inhibition of angiotensin
ACE inhibitors and Angiotensin receptor blockers
What is the difference between natriuretic and diuretics
Diuretics increase urine volume while natriuretics increases renal Na excretion
What is the equation for Blood Pressure
BP= Cardiac Output x Peripheral Vascular Resistance
What is the equation for Cardiac Output
Co= Heart Rate x Stroke Volume
What aspect of blood pressure is initially reduced by diuretics, how
Cardiac output due to reduced volume
How do diuretics still lower blood pressure when cardiac output returns to normal, when does this take place
Na depletion leads to decreased peripheral vascular resistance, 6 to 8 weeks
What class of diuretics is used for hypertension
Thiazides, Potassium-sparing diuretics
T/F: Thiazide diuretics are the most prescribed class of diuretics and are effective in treatment of mild to moderate essential hypertension
True
T/F: Diuretic effect drastically increases with higher doses with a much higher diuretic effect and no effect on Na excretion
False: Lower doses produce similar antihypertensive action but there is more of a natriuretic effect at higher doses
Why thiazides are used in hypertension
Hydrochlorthiazide, chlorthalidone, indapamide, metolazone
T/F: Thiazides inhibit NaCL reabsorption in the DCT and enhance calcium reabsorption
True
What are adverse effects of thiazides
Hypokalemia, Hyperuricimeia (gout), Hyperglycemia in diabetic patients, hyperlipidemia
What are the potassium sparing diuretics
Spironolactone, Eplernone, Triamterne, Amiloride
What are the CNS-acting sympathoplegics
Methyldopa, clonidine
T/F: In the brain methyldopa has a net effect of decreasing sympathetic outflow but has no antihypertensive action peripherally
True
What is the MOA of clonidine
Direct agonist of alpha-2 adrenoceptors in medulla of the brain causing reduced BP, bradycardia and increased parasympathetic tones
Why is sudden withdrawal from CNS-acting sympathoplegics not recommended, how can this be avoided
severe hypertensive crisis due to rebound sympathetic activity, dose should be tapered to D/C
What is the adrenergic neuron blocker that blocks uptake of NE, dopamine and serotonin leading to inhibited NE release at effector blood sites causing vasodilation
Reserpine
What is the MOA of alpha-1 adrenoreceptor antagonists
bind antagonistically to alpha-1 receptors at postganglionic sympathetic effect sites on blood vessels leading to vasodilation
What are the alpha-1 adrenoceptor antagonists
Prazosin, Terazosin, Doxaszosin
What are the non-selective Beta-blockers
Propanolol, naldolol, carteolol
What are the selective Beta-blockers
metoprolol, atenolol, bisoprolol, betaxolol, esmolol (IV only)
Which beta-blockers have mixed arendoreceptor activity but have greater agonist activity at beta-2 but are antagonists at beta-1
pindolol, acebutolol, penbutolol
Which beta-blockers have mixed adrenoreceptor activity with selective beta activity and alpha antagonist activity
Lavetalol and Carvedilol
What aspect of BP do beta-blockers effect, how
Decrease cardiac output, reduced peripheral vascular resistance
T/F: Patients with angina should not receive beta-blockers
True
What disease states are beta-blockers particularly useful in
Post myocardial infarction, high coronary risk , Heart failure
What are adverse effects from using beta-blockers
bradycardia, decrease cardiac contractility and excitability, bronchoconstriction (non-selective beta-blockers)
T/F: Symptoms of hypoglycemia may be masked by beta-blockers in diabetic patients
True
T/F: Hydralazine is a vasodilator that vasodilates arterioles and veins and is usually used in monotherapy for severe hypertension
False: Hydralazine is a vasodilator that only vasodilates arterioles and is used in combination therapy for severe hypertension
What is the MOA of minoxidil
Its metabolite opens potassium channels in smooth muscle membranes of arterioles leading to suppression of contraction
What is the other use of minoxidil
Hair growth
What are the parenteral vasodilators
Sodium nitroprusside, diazoxide, fenodopalm
What is the general MOA of calcium channel antagonists when it comes to antihypertensive activity
inhibition of calcium influx into smooth muscle of arterioles thereby inhibiting contraction
What do calcium channel blockers effect in the BP equation
reduced vascular resistance
What are the two non-dihydropyridines calcium channel blockers
Verapamil and Diltiazem
What are the dihydropyridines calcium channel blockers
Nifedipine, amlodipine, nicardipine, and felodipine
T/F: Non-dihydropyridines have more potent vasodilator effect than dihydropyridines with verapmil having the greatest effect
True
What are adverse effects of calcium channel blockers
Cardiac depression, dizziness, constipation, peripheral edema
What was the prototype drug for ACEI, ARBs
captopril, losartan
What causes stimulation of renin release from kidney cortex stimulation
decreased renal arterial pressure, sympathetic stimulation, increased Na concentration at renal distal tubule
Why do ACEs have a slight advantage over ARBs in loweing blood pressure
While they both blunt angiotensin 2 activity, ACEIs also allow for Bradykinin buildup that leads to vasodilation
What are the ACE inhibitors
enalapril, lisinopril, benazepril, fosinopril
How do ACEIs effect the BP equation
Decrease peripheral vascular resistance
What disease states have the most benefit from using ACEis
Post myocardial infacrcation, heart falure (with diuretics), chronic kidney disease, recent stroke, diabetes
T/F: High dose aspirin and NSAIDS may diminish the hypotensive response of ACEI inhibiots while low ASA appears to pose no problem
True
What disease states have the most benefit from using ARBs
Chronic Kidney Disease and Diabetes
