Kruse - Vasodilators Flashcards Preview

Renal 2 Final - Pharm > Kruse - Vasodilators > Flashcards

Flashcards in Kruse - Vasodilators Deck (55):
1

Dihydropyridines (DHPs) are _____ blockers

Calcium channel

2

Name the DHPs = 7 of them
What do they end in?
ANC FINN

Amlodipine*
Nifedipine*
Clevidipine
Felodipine
Isradipine
Nicardipine
Nisoldipine

3

Non-DHPs = 2 of them

Diltiazem
Verapamil

4

Potassium Channel Openers = 2 of them

Diazoxide
Minoxidil

5

Dopamine Agonists = 1

Fenoldopam

6

Nitric Oxide Modulators = 3 of them

Hydralazine
Nitroprusside
Organic Nitrates - Nitroglycerin + Isorbide dinitrate

7

DHP MOA?

Nifedipine, Amlodipine = prototypes

- block L-type Ca+ channels in vasculature > cardiac channels

8

Non DHP MOA?

Prototype = verapamil + Diltiazem

MOA: nonselective block of vascular + cardiac L-type calcium channels

9

Calcium channel blockers (CCB)

- dihydropyridines (DHPs) + non DHPs

10

Do DHP and non-DHP bind to same or different sites on the L-type channel proteins? What is the effect?

Different

Causes differences in effects on vascular vs. cardiac tissue responses + different kinetics of action at the receptor

11

CCBs bind effectively to what kind of channels? What does it do?

- Open and inactivated channels

- reduces the frequency of opening in response to depolarization

12

Effect of CCB on smooth muscle?

Cause vasodilation = decrease peripheral resistance

- arterioles = more sensitive than veins
- relaxed arteriolar smooth m. = decreased O2 demand by heart

13

Effect of CCB on cardiac m.

- reduced contractility in heart
- decrease in SA node pacemaker rate
- decreased conduction velocity

Note:
- non DHP have MORE cardiac effect than DHPs
- DHPs block cardiac channels in smooth muscle at lower concentrations, so cardiac effect is negligible

14

CCB Metabolism (pharmacokinetics)

Are they active when taken orally?

Yes

- high first pass metabolism

15

Which CCBs are also taken via IV = 4 of them

Nifedipine
Clevidipine
Verapamil
Diltiazem

16

Which CCB has a long half life?

Amlodipine = 35-50 hours

Other CCBs have 2-12 hours half life

17

Drug interaction between non-DHP CCBs and ______ is dangerous.

B-blockers

18

Are CCBs well tolerated?

Yes

19

Side Effects of DHPs?

Hypotension
Dizziness
Headache
Peripheral edema
Flushing
Tachycardia
Rash
Gingival hyperplasia

20

Short acting or long acting DHPs should NOT be used for chronic HTN?

Short acting - do not use!

- preferred = long acting + slow release DHPs

21

Side effects for Non-DHPs

Dizziness
Headache
Peripheral edema
Constipation* --- especially verapamil!!
AV block
Bradycardia
HF
Lupus-like rash -- with diltiazem
Pulmonary edema
Coughing
Wheezing

** verapamil > diltiazem = slow HR, slow AV conduction, cause heart block

22

Non DHPs are contraindicated in?

IMPORTANT!

Ppl taking b-blockers

23

Which DHP does NOT decrease AV conduction

Nifedepine

- can be used safely than non-DHPs in presence of AV conduction abnormalities

24

CCBs are not indicated for ____. But which 2 drugs can b used for another indication, such as ANGINA or HTN?

Use in heart failure pts

Can use amlodipine or felodipine

25

Verapamil (non DHP) can increase _____ blood level

Digoxin

26

A. DHP is an additive with ______

B. Non DHP is an additive with _____

A. Vasodilators

B. Cardiac depressants + HTN drugs

27

Potassium channel openers = 2 of them

Diazoxide
Minoxidil

28

MOA for Diazoxide + Minoxidil

Opens potassium channel in smooth muscle

29

Diazoxide

Increased potassium permeability ________ smooth muscle membrane?

Hyperpolarizes

30

Diazoxide (Potassium channel opener)

How long acting?
How is it usually administered?

Long acting = 4-12 hours after injection

- 3-4 injections, 5-15 minutes apart as needed
- sometimes via IV

31

Diazoxide

Adverse effects?

Hypotensive effects greater in? How to avoid these problems?

Excessive hypotension can cause stroke + MI
Hypoglycemia in pts with renal sufficiency
Cause Na + H20 retention (not a problem b/c short duration of use)

- hypotensive effects greater in patients with renal failure (b/c less protein binding) And pts taking b-blockers to prevent reflex tachycardia
- avoided in pts with ischemic heart disease --> risk for angina, ischemia, Cardiac failure



- should give smaller doses

32

Minoxidil effect on smooth muscle membrane ?

Increases potassium permeability = hyperpolarization of smooth muscle = reduced probablity of contraction

Dilation of arterioles, but NOT VEINS
- more efficent than hydralazine (a NO modulating drug)

33

Side Effects of Minoxidil

Headache
Sweating
Hypertrichosis (abnormal hair growth)

Effects more than with hydralazine (NO modulator)
**associated with reflex sympathetic stimulation
** increased Na + H20 retention causes:
- tachycardia
- palpitations
- angina
- edema

34

How to avoid the following effects of Minoxidil?

Effects more than with hydralazine (NO modulator)
**associated with reflex sympathetic stimulation
** increased Na + H20 retention causes:
- tachycardia
- palpitations
- angina
- edema

Use in combination with a b-blocker and loop diuretic

35

Clinical uses of Minoxidil (potassium channel opener)

- LT outpatient therapy of severe HTN

**** use to stimulate hair growth (ex. Rogaine)

36

Fenoldopam (Dopamine agonist) MOA

Agonist for dopamine D1 receptors

37

Adverse effects of Fenoldopam

Tachycardia
Headache
Flushing

38

Fenoldopam contraindications

Avoid in patients with glaucoma --- increases intraocular pressure

39

Clinical use of fenoldopam

HTN emergencies
Peri- + postoperative HTN

40

Nitric Oxide modulators = 3 of them

Hydralazine
Sodium Nitroprusside
Organic Nitrates

41

MOA for Hydralazine? Effects?

Stimulate release of NO from endothelium = increased cGMP
- cause dilation of arterioles, but NOT VEINS + reflex tachycardia

42

Side Effects of Hydralazine

Headache
Nausea
Anorexia
Palpitations
Sweating
Flushing

Rare peripheral neuropathy + drug fever

43

Contraindications for Hydralazine

Dont use in pts with ischemia Heart disease, reflex tachycardia

- sympathetic stimulation can cause angina + ischemic arhythmias

44

Clinical uses for hydralazine

- LT outpatient therapy of HTN + HTN emergencies
- combination with nitrates = effective in heart failure
- used for HTN in pregnancy (with methyldopa)

45

Sodium Nitroprusside MOA and effects

Release NO = increased cGMP

- cause dilation of arterial + venous vessels
- decrease peripheral vasc. Resistance + venous return
- in absence of heart failure, bp decreases, but CO does NOT change
- when CO = low due to HF, CO increases due to afterload reduction

46

How is Sodium nitroprusside administered?

Rapid metabolsim = short duration of effect
Given via IV
should Monitor bp!

47

Side Effects of Sodium Nitroprusside

hypotension
Cyanide + thiocyanate released during metabolism
-- no problem if drug used for short time

Long term use (few days) = metabolic acidosis, arrhythmias, excessive hypotension, death

48

Clinical use of Sodium nitroprusside

HTN emergecy
Acute decompensated heart failure

49

Organic Nitrates - two types

Nitroglycerin + isosorbide dinitrate

50

MOA for organic nitrates and Effect

Release NO via enzymatic metabolism

Effect
- relax smooth muscles (veins > arteries)
- no effect on cardiac or skeletal muscle
- decrease heart size
- CO reduced if no HF
- decrease platelet aggregation

51

Metabolism of Organic nitrates

- High first pass effect = low bioavailability
- given sublingually to avoid first-pass
- blood level reached in 15-30 min
- if want longer duration of action ---> taken orally, transdermallly, and buccally

52

How to get tolerance to organic nitrates

Compensatory response to get tolerance?
How to avoid?

Via continuous exposure

Compensatory responses
- tachycardia
- increased cardiac contractility
- rentension of Na + H20

- best to use after 8 hours to avoid tolerance

53

Side effects of organic nitrate usage?

Orthostatic hypotension
Syncope
Throbbing headache

Due to
- decreased NO release
- decreased availabilty of sulfhydryl donors
- increased Oxygen free radicals
- Decreased calcitonin gene related peptide (CGRP) availability

54

Contraindications for nitrogen oxide

Increased intracranial pressure
Remove transdermal patches if using external defibrillators

55

Drug-drug interactions btw organic nitrates and ____

Synergistic hypotension if use PDE5 inhibitors (sildenafil, tadalafil, vardenafil)