Antihypertensives2

Question 1

What is the mechanism of a drug that ends in ‘pril’?

Answer 1

They are ACE inhibitors, which prevents conversion of AngI to AngII. Also prevents inactivation of bradykinins so increases their levels. Potent antiHTN drug.

Question 2

What effect does AngII have on thirst?

Answer 2

it makes you thirsty

Question 3

What effect does AngII have on blood vessel wall thickness?

Answer 3

it stimulates thickening and neo-imtima formation in blood vessels

Question 4

What is captopril? What is its mechanism? What is unique about it?

Answer 4

ACE inhibitor that increases synthesis of prostaglandins. Also delays progression of renal disease in Type I diabetics.

Question 5

What is enalapril? What is its mechanism? What is unique about it?

Answer 5

prodrug converted to potent ACE inhibitor (enalaprilat). Used IV for HTN emergencies

Question 6

What is lisinopril? What is its mechanism? What is unique about it?

Answer 6

lysine derivative of enalaprilat, renoprotective ACE inhibitor

Question 7

What is ramipril? What is its mechanism? What is unique about it?

Answer 7

prodrug ACE inhibitor. Long lasting, once daily.

Question 8

What are adverse effects of ACE inhibitors

Answer 8

hypotension or Na depletion. Hyperkalemia, dry cough (related to bradykinin actions). Angioedema (potentially fatal and serious)

Question 9

What is the mechanism of drugs that end in ‘sartan’?

Answer 9

they are AngII receptor antagonists (ARBs). Stop most actions of AngII, BUT do not effect bradykinin or other kinins so drug of choice when ACE inhibitors cause dry cough.

Question 10

What is losartan? What is its mechanism? What is unique about it?

Answer 10

an ARB prodrug that is also a competitive antagonist of thromboxaneA2 receptor. Also increases Uric acid urinary excretion and inhibits CYP activity.

Question 11

Which ARB has the shortest half-life? Which has the longest?

Answer 11

Losartan is shortest.

Telmisartan is longest acting.

Question 12

What is telmisartan? What is its mechanism? What is unique about it?

Answer 12

ARB. It is unique because it is not cleared by kidney, thus good for patients with renal failure. Also has longest half-life of all ARBs.

Question 13

Which ARB can be used to treat gout?

Answer 13

losartan, it has a unique side-effect of increases uric acid urinary excretion.

Question 14

What is aliskiren? What is its mechanism? What is unique about it?

Answer 14

Renin inhibitor. antiHTN. Not commonly used alone because it is not as efficacious and expensive

Question 15

What is verapamil? What is its mechanism? What is unique about it?

Answer 15

cardiac L-type Ca channel blocker of phenylalkylamine class. Selective for myocardium, less effective as systemic vasodilator. Dilate coronary artery, but can cause congestive heart failure. Migraines

Question 16

What are dihydropyridines?

Answer 16

L-type Ca channel blockers. Selectively block L-type Ca channels in blood vessels. Used for HTN because they decrease SVR and MAP.

Question 17

What is diltiazem? What is its mechanism? What is unique about it?

Answer 17

mixed Ca channel blocker of the benzothiazepine class. Intermediate between verapamil and dihydropyridines in selectivity for vascular and cardiac Ca channels

Question 18

What is nifedipine? What is its mechanism? What is unique about it?

Answer 18

short acting L-type Ca channel dihydropyridine. Should NOT be used for HTN because it can increase HR by sympathetic reflex action

Question 19

What are the benefits of dihydropyridines?

Answer 19

very effective in low renin HTN.

Question 20

What are the adverse effects of dihydropyridines?

Answer 20

no proven survival benefit. can cause peripheral anklde edema and constipation.

Question 21

What is hydralazine? What is its mechanism? What is unique about it?

Answer 21

selective smooth muscle vasodilator (arterioles only). Triggers reflex sympathetic stimulation and increases catecholamine/renin secretion. Reflex increase in HR and contractility and fluid retention. Can cause palpitations, tachycardia, lupus-like syndrome.

Question 22

What is minoxidil? What is its mechanism? What is unique about it?

Answer 22

relaxes arteriolar smooth muscle by opening Kchannels in smooth muscles. Dilates arteries but not veins. Reflex tachycardia and powerful renin secretion activator. Causes hirsutism (also used to regrow hair)

Question 23

What is diazoxide? What is its mechanism? What is unique about it?

Answer 23

IV HTN treatment. opens K channels to stabilize resting membrane potential. Requires higher input to depolarise and prevents smooth muscle contraction. Reflex tachycardia, and Na retetion. Renin secretion and Increased CO. Inhibits insulin release so hyperglycemia.

Question 24

What is fenoldopam? What is its mechanism? What is unique about it?

Answer 24

D1 agonist. IV admin for HTN emergencies. Rapidly metabolized. T1/2 < 10 min. Reflex tachycardia and increased IO pressure. Avoid in gluacoma

Question 25

What is nitroprusside? What is its mechanism? What is unique about it?

Answer 25

prodrug. Forms NO to stimulate smooth muscle cGMP to cause relaxation of arterioles AND veins. Useful for treatment of heart failure. Reduces CO in normal people, BUT increases it in patients with LVF because TPR is reduced. Very short halflife and IV. Can cause excessive hypotension, pronounced tachycardia and palpitaitons. Metabolized to cyanide so no long term use

Question 26

What effect would an A2 agonist have?

Answer 26

it activates A2 receptors in brain, which INHIBITS sympathetic activity

Question 27

What is clonidine? What is its mechanism? What is unique about it?

Answer 27

central A2 agonist. Decreases sympathetic impulses and decreases TPR and HR. Can treat ADHD or for pain. can cause sedation and must be withdrawn slowly at risk of hypertension.

Question 28

What is alpha-methyl-DOPA? What is its mechanism? What is unique about it?

Answer 28

converted into a-methyl NE, a false trasmitter. Is a A2 agonist. Used to treat preeclampsia. Sedation. Can cause autoimmune reactions (+coombs)

Question 29

What is bosentan? What is its mechanism? What is unique about it?

Answer 29

endothelin-1 and endothelin-2 receptor antagonist. Endothelin is a powerful vasoconstrictor. Used to treat pulmonary artery HTN. Severe liver toxicity.

Question 30

What is a special advantage of alpha blockers?

Answer 30

they can improve both lipid profile and insulin resistance. Particularly useful in young patients who wish to remain active

Question 31

What type of HTN drug can be used to prevent stage fright?

Answer 31

B blockers.

Question 32

What is bisoprolol? What is its mechanism? What is unique about it?

Answer 32

B1-blocker used with ACEIs and diuretics. Is gold standard of treatment.

Question 33

Which IV drug is used during hypertensive emergencies, is short acting, and acts on G-coupled protein receptor?

Answer 33

fenoldopam. Acts on D1 receptor and quickly reduced BP.

Question 34

Which IV drug is used during hypertensive emergencies, is short acting, and acts by releasing nitric oxide?

Answer 34

nitroprusside