Pharmacology - Antihypertensives

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How does clonidine work?: It is an alpha-2 agonist. It stimulates central and peripheral alpha-2 receptors, decreasing central sympathetic outflow.
An IV injection of clonidine may cause what side effect?: transient increase in BP
When is clonidine used?: moderate-to-severe essential hypertension, renal hypertension, dx pheochromocytoma
What are the side effects of clonidine?: sedation, dry mouth, orthostatic hypotension, fluid retention
An abrupt withdrawal of clonidine may cause what side effect?: rebound hypertensive crisis
What drugs interact with clonidine and methyldopa?: tricyclic antidepressants (they block reuptake of norepinephrine); Ca2+ blockers decrease HR and contractibility and will have an additive effect
How does methyldopa work?: It is an alpha-2 agonist. It stimulates central alpha-2 receptors, diminishing sympathetic outflow.
When is methyldopa used?: moderate essential hypertension; hypertension in pregnancy
What are the side effects of methyldopa? (h for hint): sedation, dry mouth, postural hypotension, fluid retention, positive direct Coombs reaction in 10-20%
Name three alpha-2 agonists: clonidine, methyldopa, guanabenz
Name five selective beta-1 blockers.: acebutolol, betaxolol, esmolol, atenolol, metoprolol
Name two ISA beta-blockers. What does ISA mean?: acebutolol and pindolol; ISA means intrinsic sympathomimetic activity; these drugs have less negative inotropic and chronotropic effects, and they don't increase serum triglyercides or decrease HDL
When would you use an ISA?: in patients with decreased cardiac functioning or a tendency for bradycardia
How do beta-blockers work?: They decrease cardiac output and decrease renin secretion
What is special about labetalol?: it is a mixed antagonist; it blocks both beta and alpha receptors
What is the longest-acting beta-blocker?: nadolol, 24 hours
What is the shortest-acting beta-blocker?: esmolol, half-life of 10 minutes
Which beta-blocker is lipid-soluble and causes CNS effects? What endocrine disorder would this drug be used in?: propranolol; hyperthyroidism
Which beta-blocker has high oral bioavailability?: pindolol
When are beta-blockers used?: mild-to-severe essential hypertension, supraventricular and ventricular tachyarrhythmias, treatment of angina, acute MI, hypertrophic cardiomyopathies, hypertensive emergencies
Which two beta-blockers are used topically for glaucoma?: timolol and betaxolol
Which tumor does labetalol help treat?: pheochromocytoma
What are the side effects of beta-blockade?: bronchospasm, masking of sympathetic responses to hypoglycemia, negative inotropic effect (exacerbates CHF), heart block or bradycardia, aggravation of vasospasm
Who should not receive a beta-blocker?: asthmatics, diabetics, patients with COPD
Name three selective alpha-1 blockers.: prazosin, terazosin, and doxazosin
How do alpha-1 blockers work?: They block vasoconstriction of vascular smooth muscle (both arteriolar and venous), decreasing both afterload and preload
When are alpha-1 blockers used?: mild-to-moderate essential hypertension, CHF, pheo (prazosin), and BPH
Why are alpha-1 blockers used to treat BPH?: they promote relaxation of the urethra and trigone, and decrease urinary retention
What are the side effects of alpha-1 blockers?: postural hypotension and reflex tachycardia
Name three nonselective alpha-blockers.: phentolamine, tolazoline, phenoxybenzamine
Which alpha-blocker binds irreversibly and is therefore noncompetitive?: phenoxybenzamine
When is phentolamine used?: diagnose pheo, prevent dermal necrosis and sloughing from infiltrated drugs such as norepinephrine, autonomic hyperreflexia
When is tolazoline used?: peripheral vascular disease, Raynaud's phenomenon, autonomic hyperreflexia
When is phenoxybenzamine used?: Raynaud's phenomenon, autonomic hyperreflexia
What are the side effects of alpha-blockers?: sedation, miosis, postural hypotension, reflex tachycardia
How do nonselective alpha-blockers lower blood pressure?: They block catecholamine-induced vasoconstriction
How does reserpine work? What is its classification?: It blocks the uptake of neurotransmitters into their storage vesicles, leading to the depletion of catecholamine and serotonin stores... it also decreases cardiac output and peripheral vascular resistance; adrenergic neuron blocker
When is reserpine used?: mild-to-moderate hypertension, but rarely used at all clinically
What are the side effects of reserpine?: sedation, bradycardia, vasodilation, diarrhea, depression
Who should not take reserpine?: patients with a history of depression
How does guanethidine work? What is its classification?: It displaces norepinephrine from synaptic vesicles and inhibits its release from nerve endings; adrenergic neuron blocker
How does guanethidine enter the nerve terminal and what drugs would block this if given concurrently?: It uses uptake 1; uptake blockers (like tricyclic antidepressants... and what other antihypertensive do TCAs counteract? clonidine/methydopa!)
When is guanethidine used?: severe hypertension, but rarely used clinically
What are the side effects of guanethidine?: severe orthostatic hypotension, sexual dysfunction, fluid retention
Name three ganglionic blockers.: hexamethonium, trimethapham, mecamylamine
What do ganglionic blockers block? What does this achieve physiologically?: nicotinic receptors of autonomic ganglia; block of sympathetic and parasympathetic outflow
Ganglionic blockers are rarely used as antihypertensives today. Which drug is the exception to this rule, and in what case is it used?: trimethaphan; hypertension secondary to acute dissecting aortic aneurysm
Which reflexes do ganglionic blockers prevent?: baroreceptor reflexes
What effect does hydralazine cause and how does it achieve that?: direct relaxation of arteriolar smooth muscle; release of EDRF (nitric oxide) and interference with Ca2+ metabolism
When is hydralazine used?: moderate-to-severe hypertension (with beta-blockers and diuretic), CHF (with oral nitrates)
What are the side effects of hydralazine?: reflex tachycardia, increased myocardial oxygen consumption (MC ischemia, prevent with beta-blocker), headache, edema
What important side effect of hydralazine is related to the acetylation capacity of the patient?: lupus-like syndrome
BONUS: What other drugs cause lupus-like syndrome?
BONUS: What antibodies are seen in drug-induced lupus?

(A: procainamide, D-penicillamine; antihistone antibodies)
What effect does minoxidil have and how does it achieve that?: direct arterial vasodilation; opens K+ channels, which hyperpolarizes and relaxes vascular smooth muscle
When is minoxidil used? What should it be given with?: severe hypertension when nothing else works; beta-blocker and diuretic
What are the side effects of minoxidil?: salt and water retention, reflex tachycardia, hypertrichosis (defined as human werewolf syndrome LOL), pericardial effusion
How does diazoxide work?: It opens K+ channels and dilates arterioles; inhibits insulin release (K+ channels on B cells of pancreas)
What is diazoxide used for?: hypertensive emergencies (malignant hypertension), and hyperinsulinemia (esp. insulinoma)
When is diazoxide contraindicated?: CAD, pulmonary edema, aortic aneurysm, intracranial hemorrhage
What are the side effects of diazoxide?: excessive hypotension, salt and water retention, hyperglycemia
How does sodium nitroprusside work?: It releases NO, balanced vasodilation
When is sodium nitroprusside used?: hypertensive emergencies, acute CHF, severe mitral regurgitation with pulmonary congestion
What are the side effects of sodium nitroprusside?: hypotension, headache, diaphoresis, thiocyanate poisoning
Name the calcium-channel blockers.: dihydropyridines (-dipines), verapamil, dilitiazem; mibefradil, bepridil
How do calcium-channel blockers work? (now that's a hard one): they block Ca2+ entry into cells, which inhibits excitation-contraction coupling of vascular smooth muscle (blah, blah, they decrease PVR)
Dilitiazem and verapamil have another effect. What is it?: They slow conduction through the AV node
What are the uses of Ca2+-channel blockers?: mild-to-moderate hypertension, coronary vasospasm (Prinzmetal), supraventricular tachyarrhythmias (V&D)
What are the side effects of cc blockers?: heart block (esp. verapamil), exacerbation of CHF, hypotension (esp. verapamil) *DHPs cause gingival hyperplasia and verapamil increases plasma digoxin levels
What is the suffix of ACE inhibitors?: -pril
What is the mechanism of action of captopril?: it inhibits ACE, which potentiates the vasodilatory effects of bradykinin... leads to decrease in peripheral resistance
What other effects does captopril have? (Hint: on the kidney): reduces filtration pressure and GFR because the vasodilation of the efferent arterioles is greater than that of the afferent arterioles because aldosterone is decreased
When is captopril used?: CHF, mild-to-moderate essential hypertension; use with a thiazide diuretic
ACE inhibitors decrease proteinuria and the rate of pregression of renal failure in what patient population?: diabetics
What are the side effects of ACE inhibitors?: loss of taste, dry cough, ANGIOEDEMA, orthostatic hypotension, proteinuria (ha), eosinophilia, bone marrow toxicity (rare)
BONUS: what class of androgen treats hereditary angioedema?

(A: 17-alkyl derivatives like danazol)

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