Pharm 5 Cardio pt2 Flashcards
Do all Diuretics work in the same place in the nephron?
What do they trigger?
Each one works in a different place in the nephron. (therefore have diff advantages, side effects)
These drugs cause Na+ (and therefore also water) to be excreted.
In resistant edema, what 3 kinds of diuretics are indicated?
loop diuretics, K+-sparing diuretics, and metolazone
A concern about taking Diuretics.
electrolyte imbalances. A good chance you will excrete too much K+, and must be checked periodically in these patients on diuretics.
Diuretics are used in the management of (3)
Hypertension
Glaucoma
edema associated with cardiovascular, renal and endocrine abnormalities
For Hypertension, what’s your first choice of a diuretic? Next 2 choices?
Thiazide (first choice), Loops, and sometimes K+ Sparing.
Diuretics:Contraindications, Precautions, A/S Effects
lower the blood pressure too much
Contraindicated in anuria
electrolyte depletion
Pregnancy Cat. C
Monitor electrolytes (esp. K+), fluids, blood, BUN
K+ supplements may be needed
Some classes contraindicated in sulfanomide allergies
Caution in hepatic or renal dysfunction, DM, gout, SLE
Interaction w/ digitalis, lithium
May alter excretion of salicylates, lithium
Potentiates anti-hypertensives (that’s good!)
a poison from a plant called foxglove. What can it cause?
Digitalis
cardiac dysrhythmias
What other element gets excreted by Diuretics besides Na/K?
Lithium - in the same periodic table group as Na.
Prototypical Thiazide Diuretic Example Route of Entry Indication What's the reality?
Hydrochlorthiazide aka HCTZ (PO - tabs)
Indication: edema
Reality is: this drug is rarely written in this formulation anymore b/c this is only for monotherapy. Reality: it’s used with other drugs.
Prototypical Loop Diuretic Example, route of admin Indication What's its half life? What's the reality?
Furosemide (Lasix®) - IV
Indication: edema
Half life: 6 hours (laSIX)
It’s a good drug for edema in an in-hospital setting. Not a good drug for hypertension b/c of how quickly/dangerously it removes water from the body.
Potassium-sparing Diuretic
Example, route of admin
Indication
When would you give this?
Triamterene (PO tabs)
Indication: edema
You tried a regular HCTZ and are having trouble with K+ levels. The particular patient can’t be properly supplemented with K+, so you give this.
May be combined with HCTZ
Thiazide diuretics (Hydrochlorthiazide): consideration
Best in low-dose forms
How are all b blockers similar? (2)
Different? (4)
Similar: All b-blockers have a similar mechanism of action
b-blockers assert their effect on the Symp Nervous System
Different: beta-selectivity, alpha-blocking activity, membrane-stabilizing activity (MSA), intrinsic sympathomimetic activity (ISA)
ß-Adrenoceptor blockers
Mechanism of Action:
Why blood pressure reduction? (3)
Mechanism of Action:ß-adrenoceptor antagonism (blockade)
Heart rate slows down -> cardiac output decreases -> reduction of renin release & reduction of sympathetic outflow.
6 physiologic benefits of beta blockers
provide antihypertensive, antianginal, and antiarrhythmic effects
increases the density of beta-1 receptors
inhibit catecholamine toxicity
decrease neurohormonal activation
decrease heart rate
antioxidant and antiproliferative effects
Where are beta-1,2 receptors located, and what do they do? (3)
beta1-receptors predominate in cardiac tissue and increase heart rate and contractility
beta2-receptors predominate in the bronchial and vascular smooth muscle and cause vasodilation
beta2-receptors located in the liver promote glucogenesis
As a result of beta-blockade, __ and __ are decreased
Slowing of the atrioventricular conduction system prevents an increase in cardiac automaticity and prolongs the refractory period
Cardiac output & Heart rate
Can you list all 11 (FDA-approved) Indications for beta blockers???
Hypertension Angina Early tx, reduction in mortality in MI Selected cases of CHF Migraine prophylaxis Open-angle glaucoma Thyroidtoxicosis Subaortic stenosis Anxiety Essential tremor Selected arrhythmias
What is the only beta-blocker NOT indicated for hypertension?
Sotalol
What is the only beta-blocker indicated for hypertensive crisis?
What is it?
What’s the route of admin?
Labetolol (an injectable beta-blocker/alpha1-blocker)
the only beta-blockers indicated for heart failure (2)
Which is more common?
Carvedilol or Nebivolol
Carvedilol is more common than the much newer Nebivolol.
**How to use beta-blockers in CHF
Slow titration (up & down)
decrease symptoms of HF
improve left ventricular function
improve exercise tolerance
5 adverse effects of beta-blocker drugs
Bradycardia Bronchospasm Sexual dysfunction Fatigue Glucose metabolism?
3 types of beta-blockers
What’s the prototypical drug for each type? (1,1,2)
Non selective: Propranolol
Cardioselective: Metoprolol
Third Generation/Vasodilating: Carvedolol, Nebivolol
Are non-selective beta blockers as good as cardioselective beta-blockers in reducing blood pressure?
Non selective (propanolol) and cardioselective (Metoprolol) ß-blockers are equally effective in reducing blood pressure
