Drugs Affecting ANS

Question 1

Adrenergic Agonist

Answer 1

Question 2

Branches of the ANS

Answer 2

Question 3

Know clonidine (Catapres)

Answer 3

MOA:* MOA: activation of central alpha2 receptors results in inhibition of cardioacceleration &
vasoconstriction centers in the brain
* Leads to decreased outflow of norepinephrine
* Leading to decreases in peripheral resistance, renal vascular resistance, HR & BP by reducing sympathetic function
* Can lead to compensatory effect of retaining sodium (expand blood volume)
* Thus, sometimes given with diuretic

Question 4

Contraindications for clonidine

Answer 4

severe coronary insuf, recent MI, renal function impairment
* Avoid clonidine if risk of depression

Question 5

Alpha 2 Agonists - Methyldopa (Aldomet) recommendations

Answer 5

pregnant women
breastfeeding women
Children <12

Question 6

methyldopa special requirements

Answer 6

LFT
hemolytic anemia

Question 7

doxazosin (Cardura)
terazosin (Hytrin)

Answer 7

Selective Alpha 1 Antagonist
MOA: blocks alpha 1 receptors in smooth muscle; vasodilates arteries
B. bladder neck and prostate smooth muscle (relieve outflow obstruction)

Question 8

Selective Alpha 1 Antagonist Adverse Effects

Answer 8

Orthostatic hypotension - known for first dose effect - give dose at bedtime
-rebound tachycardia
-nasal congestion
-fluid retention
-sexual dysfunction

Question 9

This class of drug may reduce total cholesterol & tryglycerides and increase HDL; enhance insulin sensitivity; regress LVH

Answer 9

Selective Alpha 1 Antagonists
doxazosin and terazosin

Question 10

Beta Adrenergic Antagonists

Answer 10

Block sympathetic (adrenergic) response by competing for beta receptors
* ***practically all therapeutic effects result from beta 1 blockade in the
heart. The major consequences/actions of blocking these receptors are:
* 1. decrease HR
* 2. decrease contractility
* 3. decrease velocity of A-V conduction
* Also prevent renin release (less water retention)

Question 11

Beta 1 Cardioselective drugs

Answer 11

metroprolol (Lopressor)
atenolol (Tenormin)
- Children

Question 12

Non cardioselective B 1 & 2 drugs

Answer 12

propranolol (Inderal)
- Children
labetolol (Trandate)
- Alpha & Beta blockade

Question 13

Third Generation Beta Blockers

Answer 13

nebivolol (Bystolic)
* Block beta1 - very cardioselective
* Increases nitric oxide release
* Approved for hypertension
* Less likely to produce
problematic DM effects

carvedilol (Coreg)
* BB noncardioselective
* Vasodilation by alpha blockade
* Approved for CHF, HTN, LV
dysfunction after MI

Question 14

Beta blocker adverse effects

Answer 14

Beta 1 blockade:
* Bradycardia
* Decreased CO
* Precipitation of CHF (in high doses)
* A-V block
* Rebound cardiac excitation

• Beta 2 blockade:
• Bronchospasm
• Inhibition of glycogenolysis (breakdown of glycogen to glucose)
• Also impaired insulin release
• Fatigue, depression
• Sexual dysfunction/Impotence

Question 15

BB Teaching points

Answer 15

• Teach patients to monitor:
• pulse daily (call if <50 bpm)
• blood glucose (diaphoresis is not masked)
• BP
• Do NOT abruptly withdraw (decrease by ½ q 4 days)

Question 16

Angiotensin Converting Enzyme Inhibitors (ACE I)

Answer 16

• Block the enzyme that normally converts
  angiotensin I to the potent
  vasoconstrictor angiotensin II
• By blocking the production of angiotensin
  II, the drugs decrease vasoconstriction
  and decrease aldosterone production
  (thereby reducing retention of sodium
  and water)
• Reduce both preload and afterload

Question 17

List ACE I

Answer 17

lisinopril (zestril)
captopril (Capoten)

Question 18

ACE I uses

Answer 18

HTN
Hypertensive Protienuric Diabetes
- renal protective (slows progression of diabetic nephropathy
Angina and ischemic heart disease
post MI
Heart failture

Question 19

ACE I Adverse Effects

Answer 19

• Cough
• Angioedema (swelling of face, eyes, lips, tongue)
• Occurs within first dose - 1st month
• Usually within 1st week
• Hyperkalemia
• Caution: renal impairment, salt substitutes, K-supplements, K-sparing diuretics
• Hypotension (dizziness, HA)
• Rash
• Neutropenia
• Renal insufficiency (monitor proteinuria, BUN, Creatinine)

Question 20

ACE I Absolute Contraindications

Answer 20

Bilateral Renal Artery Stenosis
Angioedema
Pregnancy

NSAIDs reduce hypotensive effect

Question 21

Angiotensin II Receptor Blockers (ARBs)

Answer 21

Instead of decreasing production of angiotensin II, these drugs compete for receptor sites.

No cough or angioedema

Still contraindicated in pregnancy

Question 22

Losartan (Cozar)
valsartan (Diovan)

Answer 22

ARBs

Question 23

Renin Inhibitor

Answer 23

aliskerin (Tekturna)

Direct renin inhibitor: decreases the conversion of
angiotensinogen to angiotensin I
* Plasma renin activity is not increased
* Use: HTN
* Adverse Effects:
* Angioedema, cough
* Hyperkalemia
* Substrate CYP 3A4
* Contraindication: pregnancy

Question 24

Calcium Channel Blockers MOA

Answer 24

Block the influx of calcium which results in: * 1. relaxes arterial smooth muscle (decrease afterload)
* 2. decreases cardiac contractility (negative inotrope)
* 3. decreases sinoatrial (SA) and atrioventricular (AV) nodal conduction
* ***blocking action of CCBs occurs via different receptors

Question 25

Non-Dihyropyridines MOA and Use

Answer 25

Calcium Channel Blocker Primary site is heart * Decrease contractility * Decrease conduction * Dilate coronary arterioles * Best choice for CAD * ***avoid in HF * verapamil (Calan) * diltiazem (Cardizem)

Question 26

Dihydropyridines

Answer 26

Calcium Channel Blocker Primary site is arterial smooth muscle * Thus, greater degree of vasodilation * Best choice for hypertension * ***avoid in unstable angina (tachycardia) and with significant peripheral edema * amlodipine (Norvasc) * nicardipine (Cardene) * nifedipine (Procardia)

Question 27

Calcium Channel Blockers Adverse Effects and concerns

Answer 27

Adverse Effects: * HA, dizziness, hypotension * Bradycardia (verapamil & diltiazem) – call if HR <50 bpm * Peripheral edema * Constipation (more with verapamil) * Contraindications: * 2nd or 3rd degree AV block * Severe HF * Aortic stenosis * Work well in Black population * All CCBs are on CYP 3A4 substrate * Careful with grapefruit juice (3A4 inhibitor)

Question 28

hydralazine (Apresoline)

Answer 28

direct arterial vasodilator (decrease afterload) * Limited effect on HTN when used alone B/C vasodilating action that decreases BP also stimulates compensatory mechanisms: * Increased HR (SNS) * Sodium & water retention (RAAS) * May take with beta-blocker (prevent the tachycardia) and diuretic (prevent sodium & water retention)

Question 29

hydrochlorothiazide chlorthalidone

Answer 29

Thiazide DiureticsMOA: Decrease reabsorption of Na & Chloride in the distal tubule; exert effect on luminal surface of the tubule; requires adequate renal perfusion * Ex: hydrochlorothiazide (HCTZ) chlorthalidone * Uses: * Ineffective when immediate diuresis is required * Primary use is long-term management of hypertension and HF * Relatively ineffective with decreased renal function * Assess for allergies to sulfonamides (chemically related)

Question 30

* Orthostatic hypotension * Electrolyte imbalances: * Hypokalemia * Hypercalcemia * Hyponatremia * Hypomagnesium * Glucose intolerance (may impair pancreatic release of insulin & diminish tissue utilization of glucose) * Dry mouth * Potentiate uric acid retention * Transient increases in chol, LDL, triglycerides

Answer 30

Adverse effects of thiazide diuretics

Question 31

Loop Diuretic - Name two

Answer 31

furosemide (Lasix) torsemide (Dermadex)

Question 32

Loop Diuretics MOA

Answer 32

* MOA: Block reabsorption of Na and Chloride in the ascending loop of Henle, where the greatest Na reabsorption occurs * Ex: furosemide (Lasix) torsemide (Demadex) * Use: * Hypertension * HF * Diuretic of choice when more rapid or potent effects are needed (pulm edema) * Their sodium losing effect is up to 10X greater than thiazide diuretics * May use with renal insufficiency (Creatinine clearance <25 mL/min) * Schedule last dose early enough to prevent nocturia (4:00 pm)

Question 33

Loop Diuretic Adverse Effects

Answer 33

Electrolyte imbalances: * Hypokalemia * Hypercalcemia * Hyponatremia * Hypomagnesium * Excessive diuresis * Orthostatic hypotension * Glucose intolerance * High doses = transient hearing loss * Hyperuricemia

Question 34

Loop Diuretics Teaching

Answer 34

* Maintain potassium levels in cardiac patients at 4-4.5 mEq/L * Potassium supplement: * PO – give with meals to decrease GI distress * Liquid – mix with juice to improve taste * Teach patient: * Consume diet with potassium rich foods * Report muscle cramps, irregular heart beat, weakness

Question 35

K sparing diuretics

Answer 35

* MOA: Promote Na excretion but retain potassium in the distal tubule * Ex: spironolactone (Aldactone) * Aldactone antagonizes aldosterone (aldosterone promotes retention of sodium & water & excretion of K) * Uses: * Not used as often as primary diuretic (typically used in combo with K-losing diuretic) * Primary utility is to block aldosterone action in HF * Hypertension * Good choice in pregnancy * Contraindication: impaired renal function (due to risk of hyperkalemia) * Adverse Effects: * Hyperkalemia (teach pt to avoid high K diet; avoid salt substitutes that contain K chloride) * Hypotension * Hyperuricemia * Gynecomastia

Question 36

JNC VIII HTN Guidelines

Answer 36

First Line Classes: * 1. Thiazides * 2. ACE Inhibitors * 3. ARBs (Angiotensin Receptor Blockers) * 4. CCB (Calcium Channel Blockers) No beta blocker

Question 37

Initiating HTN Treatment

Answer 37

* 1. >60 yo <150/90 * 2. <60 yo <140/90 * 3. All ages with Diabetes <140/90 * **Non-Black * Thiazides, ACEI, ARB, CCB * **Black * Thiazides, CCB * 4. All ages chronic kidney disease (CKD) <140/90 * **treat with ACEI or ARB

Question 38

Can you use ACEI and ARB together?

Answer 38

No