Antihypertensives Flashcards

1
Q

How do sympatholytics lower blood pressure?

A

reduce sympathetic vasomotor tone
act on adrenergic receptors by either:
1. stimulation or activation of central agonists
OR
2. inhibition or blockade by peripheral antagonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where do sympatholytics act?

A

sympatholytics interrupt the efferent sympathetic pathway at different sites as:

  • medullary centers
  • sympathetic neurons
  • adrenergic receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name 2 centrally acting sympatholytics

A

Clonidine (Catapres)

Methyldopa (Aldomet)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Clonidine and Methyldopa: class and MOA

A

Class: Centrally Acting Sympatholytics
MOA: stimulates medullary alpha-2 adrenergic receptors->reduce peripheral symp. nerve activity
-stim. presynaptic alpha 2 receptors and REDUCE transmitter release at relevant sites
-stim. post synaptic alpha 2 receptors and INHIBIT appropriate neurons
in the BRAIN, ACTS AS AGONIST (UNIQUE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Clonidine and Methyldopa: indications/therapeutic effects

A

symp inhibition lowers BP by decreasing vasoconstrictor tone AND DECREASING RENAL RENIN SECRETION (by decreasing renal symp stimulation)
-cardiovascular reflexes remain intact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which sympatholytic agent lowers heart rate and cardiac output more?

A

CLONIDINE lowers heart rate and cardiac output more than Methyldopa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

DOC for treating HTN in pregnancy

A

Methyldopa, which is a PRODRUG that is converted to alpha-methylnorepinepherine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Sympatholytics: route of administration

A

(U) given orally

Clonidine can also be used as a transdermal or skin patch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pharmokinetics of sympatholytics

A

Clonidine, guanabenz and guanifacine ACT DIRECTLY but METHYLDOPA IS A PRODRUG that is converted to alpha-methylnorepinepherine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Adverse effects of sympatholytics

A

SEDATION and other CNS effects (nausea, dizziness, nightmares, depression, etc)
xerostoma (dry mouth)
toxic doses of clonidine->pressor effects (stim of alpha1 receptors
METHYLDOPA may also produce: HEMOLYTIC ANEMIA W/+COOMBS TEST, hepatotoxicity, increased prolactin secretion, gynecomastia and lactation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Methyldopa adverse effects

A

Common to all sympatholytics: SEDATION (&other CNS effects), xerostoma

Unique to methyldopa: HEMOLYTIC ANEMIA W/ POSITIVE COOMBS TEST, hepatotoxicity, increased prolactin secretion, gynecomastia and lactation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Clonidine and Methyldopa cantraindications

A
  • Not recommended for monotherapy b/c of CNS effects
  • SUDDEN WITHDRAWAL OF CLONIDINE MAY CAUSE A HYPERTENSIVE CRISIS
  • TCAs and yohimibine inhibit clonidine’s therapeutic action
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name 3 alpha 1 adrenergic antagonists

A

the “-zosins” Prazosin (minipress), Terazosin (Hytrin), Doxazosin (Cardura)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

MOA for the “-azosin” drugs & what are their names again

A

Prazosin, Terazosin and Doxazosin block alpha 1 receptors without affecting alpha 2 adrenergic receptors; alpha 1 adrenergic block reduces NE vasoconstriction to dilate both arteries and veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Indications/Therapeutic Effects for Prazosin, Terazosin and Doxazosin

A

alpha 1-adrenergic block reduces NE vasoconstriction->dilates arteries and veins->BP falls b/c decreased peripheral resistance
DO NOT ADVERSELY EFFECT PLASMA LIPIDS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What initial drug treatment should be used for most patients with uncomplicated hypertension?

A

Thiazide-type diuretics, either alone or combined with drugs from other classes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 2nd line drugs for:
Caucasians
African Americans

A

Caucasians: ACE inhibitors or ARBs

African Americans: CCBs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do thiazides do their thing?

A

Thiazides lower BP by 10-15 mmHg (1st line drug tx in ALL pts, work as monotherapy in 40-60%)
INITIALLY: They lower blood pressure by reducing body Na+ stores and decreasing blood volume and cardiac output
LONG-TERM: they decrease sodium content in muscle cells and decrease sensitivity to vasopressor agents
AFTER 6-8 weeks: activate K+ channels-> DECLINE IN PERIPHERAL RESISTANCE

19
Q

Indapamide: what is it and why is it special

A

Indapamide is a thiazide diuretic that

IS ALSO A DIRECT VASODILATOR (potentially by Ca2+ channel blockade)

20
Q

Common side effects of thiazides

A
  • INCREASED PLASMA LIPID CONCENTRATION
  • REDUCED GLUCOSE TOLERANCE
  • gout due to hyperuricemia
  • increased renin secretion
  • K+ depletion leads to hypokalemia and muscle cramps, polymorphic ventricular arrhythmia, ischemic ventricular fibrillation
  • impotence (erectile dysfxn)
  • others
21
Q

Thiazide dosage: HTN vs. diuresis

A

antihypertensive dosages are MUCH LOWER than diuresis doses (e.g. HCTZ daily doses: 100-200 mg for diuresis vs. 25-50 for HTN)

22
Q

How to avoid side effects? Limitations of this?

A
most side effects can be avoided w/lower doses
some SEs (IMPOTENCE isp in elderly will still occur w/low doses )
23
Q

First Choice DOC in HTN tx

A

Thiazides

24
Q

What diuretics are cheapest?

A

Thiazides

25
Q

Who are thiazides more effective for?

A

more effective in African American than in Caucasians

Elderly than in younger hypertensives

26
Q

Why use loop diuretics in HTN?

A

sever cases, patients with renal insufficiency, CHF

27
Q

Why use potassium sparing diuretics in HTN?

A

use in comb w/HCTZ and loop diuretics to decrease loss of K+

avoid combo. w/ other potassium-sparing drugs

28
Q

What line drugs are alpha adrenergic antagonists? What are they good for?

A

generally 3rd line drugs

useful in tx benign prostatic hyperplasia so can be used as 1st in tx in men w/BPH

29
Q

Adverse effect of alpha1 adrenergic antagonists

A

postural HTN esp w/first dose (FIRST DOSE PHENOMENON)
reflex tachycardia (but less than nonselective a-blockers)
Na+ and H20 retention (increase renin)
other mild infrequent: drowsiness, dizziness, palpitations, headache, fatigue

30
Q

Name the non-selective beta-adrenergic antagonists

A

Propanolol, Nadolol, Tomolol

31
Q

Name the cardioselective beta blockers. What receptor are they selective for and which pts is this good for?

A

selective B1 blockers; preferred to asthmatic or diabetic hypertensives
Metoprolol, Acebutolol, Atenolol, Nebivolol

32
Q

Name the B-blockers with intrinsic sympathomimetic activity and which pts is this good for?

A

Acebutolol, Pindolol

33
Q

Beta blockers age and effectiveness in tx HTN?

A

White>black

Young>old

34
Q

For whom are beta blockers are least preferred drugs? (6)

A
high physical activity
African heritage
asthma
diabetes milletus
hypercholesterolemia
peripheral vascular resistance
35
Q

How and where do beta blockers work? (3 places)

A

lower BP by blocking B-adrenergic receptors in:
heart->reduce cardiac output
KIDNEYS->REDUCE RENIN SECRETION
CNS->reduce sympathetic vasomotor tone

36
Q

Beta blocker are only recommended for HTN monotherapy in what group of peeps?

A

young white males

37
Q

What conditions make you preferentially grab a beta blocker for tx of HTN? (3)

A

angina
following myocardial infection
migraine

38
Q

Give me a good reason combine a beta blocker with other antihypertensives

A

reflex tachycardia

increased renin secretion

39
Q

Propanolol: what class is this and what are its major side effects?

A

Non-selective beta blocker
SEs mainly:
heart and lung (negative inotropic, chronotropic, dromotropic effect, bronchoconstriction)
GI (diarrhea, constipation, nausea, vomiting)
CNS (insomnia, lassitude, nightmares, depression)

40
Q

Beta adrenergic antagonists effect of exercise tolerance

A

when tx angina, B-blockers (U) increase exercise tolerance
BUT by reducing cardiac output, they can also decrease exercise tolerance (manifested as earlier onset of fatigue esp. in pts w/CHF)

41
Q

What HTN drug predisposes ppl to atherogenesis and how?

A

Beta blocker may predispose ppl to atherogensis by increasing plasma triglycerides and decreasing HDL-cholesterol

42
Q

Beta-blockers and DM?

A

B-blockade inc. risk of developing DM in HTN pts

B-blockers mask sxs of initial hypoglycemia (tachycardia, tremors) and delays recovery from hypoglycemia b/c hypoglycemic responses are mediated by epinephrine

B2 blockade also reduces insulin release

43
Q

B-blocker contradindications (4)

A

diabetes
severe congestive heart failure
heart block
asthma