diuretics updated Flashcards
Diuretics GOAL
increase rate of urine formation
Increase urine volume
net loss of solute (electrolytes) and water
Osmotic Diuretics GOAL
Increase osmotic pressure of tubular filtrate
fluid moved from ICF to ECF, inhibits renin release
Increases renal blood flow
excretion of electrolytes–Na, K, Ca, Mg, Cl, HCO3, Phosphate
Osmotic Diuretics
Mannitol (Osmitrol)
Uses
- reduce CSF pressure– with cerebral edema or pre or post neuro surgery
- Reduce intraocular pressure–glaucoma and pre-op
- Increase urine flow to prevent nephrotoxicity–dilute toxic substances
Osmotic Diuretics
Mannitol (Osmitrol)
Adverse effects
- Headache, nausea, vomiting
- with CHF–risk of fluid overload by increased ECF
- Contraindicated with CHF, renal failure, hepatic failure
Osmotic Diuretics
Mannitol (Osmitrol)
Nursing Implementations
- Give IV via filter
- Monitor output, BP
- Lungs sounds
- Serum osmolality, electrolytes
- Intracranial pressure
Carbonic Anhydrase Inhibitors GOAL
- Lower intracellular pressure (IOP)
- Not increase urine production
- urine alkalizes, metabolic acidosis a risk
- marked potassium excretion
- Reduce aqueous humor production by (Ca inhibition in ciliary processses of the eye
- Reduce intraocular pressure
Carbonic Anhydrase Inhibitors
Acetazolamide (Diamox)
Uses
- Glaucoma, eye surgery
- Allalinize urine for drug excretion
- Altitude sickness
(low to Mod. Efficacy to mobilize edema)
Carbonic Anhydrase Inhibitors
Acetazolamide (Diamox)
Adverse Effects
- Sulfoamide derivatives (watch for sulfa drug allergies)
- Hypokalemia (cause to loose potassium)
- Metabolic acidosis (contraindicated with COPD (Resp Acidosis))
- Paresthesias (pins and needles)
- Risk of renal calculus R/T CaPO4 precipitation in alkaline urine (stay hydrated)
Thiazide Diuretics Goal
- Sulfonamide derivatives
- Increase excretion of Na+ and H2O
- Increase excretion of K+
- Loss of Mg+
- Retention of Ca++
Some antihypertensive effect
Thiazide Diuretics
Hydrochlorothiazide(HCTZ, Hydrodiuril)
Uses
- Edema in mild-Mod CHF
- Treat Hypertension –Mild-Mod HTN –often first line drug
- Edema in hepatic disease
- early, mild renal disease – less effective with more advanced disease
- Combo’s with antihypertensive–synergistic effects
Thiazide Diuretics
*Hydrochlorothiazide(HCTZ, Hydrodiuril)
Adverse effects
- Electrolyte loss –esp K+
- Loss of other electrolytes –Na+, Cl-, H+
- Retain Ca++, Uric acid
- Renal insufficiency aggravated
- Hyperglycemia in diabetics–reduces effectiveness of oral agents and Insulin
- Hyperlipidemia
Thiazide Diuretics
*Hydrochlorothiazide(HCTZ, Hydrodiuril)
Nursing interventions
Monitor BP, K+, edema monitor BG's for diabetics May need potassium supplements K+ containing foods: citrus, bananas, salt substitutes etc Check for sulfa allergy
Loop Diuretics –High Ceiling– Goals
inhibit electrolyte re absorption in ascending loop of Henle, weak carbonic anhydrase effects
increase renal blood flow
some decrease in BP–? Prostaglandidn effect
Increase loss of K+, Mg, acid, ammonia (liver failure)
Rapid onset, short duration–except in renal, hepatic disease
Sulfa derivatives (allergies)
Loop Diuretics
Furosemide (Lasix)
Uses
edema of cardiac, renal, hepatic origin
acute pulmonary edema
early renal failure, nephrotic syndrome
hypertension
Loop Diuretics
Furosemide (Lasix)
Adverse Effects
Electrolyte loss – K+, Na++
Sulfa Allergy (except Ethacrynic acid)
Ototoxicity – high dose–reversible (Ethacrynic acid worse)
Hypotension – high dose – Esp. IV
Diabetics – hyperglycemia ( up BG)
long term –Ca++ or Mg+ loss
Increased LDL, Cholesterol, Triglycerides
Loop Diuretics
Furosemide (Lasix)
Nursing implications
monitor I&O, BP, electrolytes– K+, may need K+ supplements
edema, daily weight
toxicity
provide means to void or cath (30 min)
PO – 8 hour duration– give early in the day
diabetics–monitor glucose
Aldosterone antagonists GOAL
Potassium sparing diuretics
competitive antagonists of aldosterone
loss of sodium, water: CONSERVATION OF POTASSIUM
SLOW ONSET 24-48 HOURS
Aldosterone antagonists
Spironalactone (Aldactone)
Uses
hypertension, edema
drug of choice for edema and ascites with hepatic disease
some use with CHF
treat primary hyperaldosteronism (adrenal tumors)
antagonists
Spironalactone (Aldactone)
Adverse Effects
hyperkalemia (affinity for progesterone and androgen receptors)
gynecomastia, impotence, menstrual irregularity (not with eplerenone)
antagonists
Spironalactone (Aldactone)
Nursing implementations
CAUTION WHEN COMBINED WITH OTHER DIURETICS, ACE INHIBITORS OR IN RENAL DISEASE, NO POTASSIUM SUPPLEMENTS
ALSO NOT SALT SUBSTITUTES( they contain KCl
Why Combos??
Better diuresis with 2 sites of action
usually less problem with K+
Effects vary **STILL MONITOR K+**
Other Combos
thiazides with antihypertensives ***MUST KNOW OTHER COMBOS
Nitrates Goals
Source of nitric oxide–leads to relaxation of vascular smooth muscle by
dilate arterial and venous smooth muscle
reduce myocardial oxygen demands/ dilate coronary vessels/reduce preload and afterload
No change in heart rate or force of contraction
Nitrates has other effects
Dilate smooth muscle – GI tract – especially esophagus
Nitrate dependence/tolerance–mechanism not clear but is not universal.(some develop only partial tolerance)
Ideally, interrupt therapy for 8-12 hours/day
Nitrate
Nitroglycerin (NTG)
Uses:
treat or prevent angina
chest pain with MI
may reduce the size of MI
adjunct therapy for CHG
Nitrate
Nitroglycerin (NTG)
Adverse effects
Headache
flushing, dizziness, arteriole vasodilation
hypo tension – especially postural, worse with ETOH
treat with supine position
if Bp too low to provide adequate cardiac output can worsen ischemia
Nitrate
Nitroglycerin (NTG)
Interactions:
with phosphodiesterase-5 inhibitors (Viagra)
These also increase nitric oxide
can cause extreme hypo tension (treat with fluids and alpha agonist )
MUST NOT USE NITRATES WITHIN 24 HOURS OF VIAGRA, ETC
Nitrate
Nitroglycerin (NTG)
IV
titrate to reduce chest pain in ACS (MI, unstable angina)
Reduce preload–>reduce pulmonary congestion in acute CHF
Rapid onset/ short duration
maintain BP >100 systolic // min to min BP
observe for headache
Nitrate
Nitroglycerin (NTG)
Sub lingual
Onset 1-2 min, relief in ~3 min (spray is faster)
DO NOT SWALLOW
rinse mouth if dry before giving tablets or spray
deteriorates in heat and light/ keep in dark, tightly closed container
Angina teach
rest with pain
take NTG SL, repeat in 5 min if needed
if NO RELIEF after 3 NTG call 911
rise slowly
ETOH will increase any side effects
Nitrate
Nitroglycerin (NTG)
Trans dermal patch
slow onset, peak 1-2 hours, lasts 24 hours
place where visible, non-hairy, not over bony prominences
change every 24 hours or so
Nitrate
Nitroglycerin (NTG)
Paste
relieve ACUTE angina onset ~ 30-60 min, duration 4 hours measured in inches same placement as patch cover with occlusive material
Nitrate
Nitroglycerin (NTG)
Oral Pills/ capsules
for more than occasional angina
some debate on effectiveness–requires high enough dose to develop tolerance and increase risk of adverse reaction
Nitrate
Nitroprusside (Nipride) goal
relax arteriole and venous smooth muscle
reduce preload and afterload
releases cyanide ion from smooth muscle
worse over time (3-4 days) toxicity, worse in renal disease
Nitrate
Nitroprusside (Nipride)
use
Treat hypertensive crisis
treat severe CHF (with inotropics)
Nitrate
Nitroprusside (Nipride)
given
IV--via pump, titrate to effect
rapid onset (1-2) min
short duration(3min)Nitrate
Nitroprusside (Nipride)
nursing interventions
monitor BP frequently (arterial cath)
Monitor thiocyanate levels
(IV pump usually only given in ICU setting)
Inotropic Medications
Digoxin (Lanoxin)
Uses
used for CHF
to slow ventricular rate in atrial fibrillation and flutter
IT INCREASES CONTRACTILITY IN CHF
DUE TO POTENTIAL TOXICITIES, RESERVED FOR THOSE UNRESPONSIVE TO ACE INHIBITORS AND BETA BLOCKERS
Inotropic Medications
Digoxin (Lanoxin)
Adverse Effects
High risk for Toxicity
narrow range of therapeutic index or range
risk increases with renal disease , hypokalemia
Inotropic Medications
Digoxin (Lanoxin)
Toxicity
nausea, vomiting, diarrhea malaise, confusion Bradycardia, leads to heart block ventricular tachycardia, fibrillation ***Visual effects : blurred vision, halos around lights, seeing yellow/red spots
Inotropic Medications
Digoxin (Lanoxin)
treat toxicity
stop drug, treat dysrhythmias
get serum drug level
Digozin immune Fab (Digibing)
binds digoxin, readily excreted, monitor K+
Inotropic Medications
Digoxin (Lanoxin)
Nursing implications
Can give PO or IV
digitalization–can take a week to reach steady state
use loading doses to reach steady state in 24 hours–not often used
monitor therapeutic blood levels
check apical pulse 1 min before giving
hold if 120
monitor K+ especially with diuretics
rapid digitalization requires cardiac monitoring
Inotropic Medications
Dopamine (Intropin)
Goal
it is positively chronotropic
it is positively inotropic
increases cardiac output with minimal increase in myocardial oxygen consumption
Inotropic Medications
Dopamine (Intropin)
Uses
treat hypotension in shock
Severe CHF or cardiogenic shock (short term)
Inotropic Medications
Dopamine (Intropin)
nursing
given via IV pump in ICU setting
dose calculated by weight –mcg/kg/min–verify calculations
Arterial BP, cardiac output
IV site for extravasation–risk for tissue necrosis due to vasoconstriction
EKG for tachycardia
urine output for renal function
Inotropic Medications
Dopamine (Intropin)
Doses
low dose: affects Dopamine receptors
dilate renal and mesenteric vessels
improve response to diuretics
Mod dose: affect Beta 1 receptors
increase heart rate, contracitlity
some increase in BP due to norepinephrine release
High dose: affects Alpha receptors
increase BP, vasoconstriction
most useful in shock (sepsis, anaphylaxis)Nesiritide (Natrecor)
what is it
human b-type natriuretic peptide (hBNP)
Endogenous hBNP secreted by ventricles
in response to fluid and pressure overload
Nesiritide (Natrecor)
Goal
reduce preload and afterload
natriuresis, diuresis,
suppress renin-angiotensin system
lowers norepinephrine effects
enhances endogenous hBNP function
reduces pulmonary capillary wedge pressure and dyspnea
can see hypotension
can use for acute CHF treatment–given IV
can be combined with diuretics, others CHF meds
Also remember
ACE inhibitors–reduce afterload, decrease ventricular remodeling (first line drugs for CHF
And remember this too
Beta-Blocker –Carvedilol –(mixed alpha 1 and Beta) reduce afterload
antiproliferative properties
