diuretics Flashcards
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Diuretics are medications that inc urine formation and outut
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**they inc renal excretion of water, sodium, and other electrolytes, thereby increasing urine formation and output. They are used in management of edematous and non-edematous conditions.
diuretics are used in management of what conitions?
**Edematous: HF, renal disease, hepatic disease
Non-edematous: HTN, ophthalmic surgery
what is the primary renal function? how much of CO do they receive
regulate vol, composition and pH of body fluids
kidneys receive ~25% of CO
what is the functional unit of the kidney?
nephron
the kidney (nephron) functions via 3 processes. what are these processes?
glomerular filtration, tubular reabsorption, and tubular secretion
what is the day min urine output?
400 ml. remove normal amounts of metabolic end products
diuretics act on kidneys to what?
**decrease reabsorption of sodium, chloride, water, and other substances
what are the major subclasses of diuretic drugs?
thiazides and related diuretics
ooo diuretics
potassium-sparing diuretics
major clinical indications of diuretics? and how for each?
edema- mobilize tissue fluids of decreasing plasma
heart failure
HTN- exact mechanism unknown, attributed to sodium depletion
which diuretic is preferred when rapid diuretic effect is needed?
loop diuretic ***
what diuretic is used to manage hypokalemia?
potassium sparing diuretic
examples of loop diuretics?
Bumetanide*
ethacrynic acid (rarely used clinically)
Furosemide* (Lasix®)
MOA of loop diuretics?
**acts directly on the loop of hence to block chloride and sedum resorption
inc kidney prostaglandins, resulting in the dilation of bleed vessels and reduced kidney, pulmonary, and systemic vascular resistance
what treatment are loop diuretics good for?
useful in treatment of edema
do loop diuretics have a slow or rapid onset? how long do they last?
rapid onset and last at least 2 hours
the decreased fluid vol causes a reduction in what for loop diuretics?
BP pulmonary vascular resistance systemic vascular resistance central venues pressure left ventricular end-diastolic pressure
what do loop diuretics deplete someone of? what should you teach the patient?
**K and Na
small calcium loss
tell them to take K supplements or eat bananas
indications of loop diuretics?
deem associated with heart failure and liver or kidney dsease
HTN
kidney excretion of calcium in patients with hypercalcemia
heart failure resulting from diastolic dysfunction
adverse effects for loop diuretics? CNS GI, metabolic, and hematological
CNS: Dizziness, headache, tinnitus, blurred vision
GI: ausea, vomiting, diarrhea
hematological: Agranulocytosis, neutropenia, thrombocytopenia
metabolic: Hypokalemia, hyperglycemia***, hyperuricemia
where are loop diuretics toxic?
neurotoxic and nephrotoxic
loop diuretics inc serum levels of what?
uric acid, glucose, alanine aminotransferase, and aspartate aminotransferase
loop diuretics combined with thiazide (metolazone) cause what?
results in the blockade of sodium and water reabsorption at multiple sites in the nephone, a property referred to as sequential nephrite blockade
what may dec the reduction of vascular resistance? in loop diuretics so what impedes the effects of loop diuretics?
NSAIDS ***
what is the most commonly used loop diuretic?
furosemide (lasix)***
what are the uses for furosemide ?
pulmonary edema and edema associated with HF,l over dx, nephrotic syndrome, ascites, htn
how to administer furosemide?
why this way?
nurse gives IV injections of furosemide over 1-2 min and administers high-dose furosemide continuous IV infusions at a rate of 4mg/min or less
dec or avoids high peak serum levels, which inc risk of adverse effects, including ototoxicity
When administering a loop diuretic to a patient, it is most important for the nurse to determine if the patient is also taking which drug?
lithium
acetaminophen (Tylenol®)
penicillin
theophylline
lithium bc
Correct answer: A
Rationale: Use of loop diuretics with lithium can increase the risk of lithium toxicity. Drug interactions with loop diuretic therapy can occur with concurrent use of nonsteroidal anti-inflammatory drugs, and vancomycin can cause increased neurotoxicity and ototoxicity when used with loop diuretics. There is no associated risk of drug interaction when acetaminophen, penicillin, or theophylline are taken with loop diuretics.
Because lithium is a salt so if youre taking lithium it will affect diuiretic and may eed to lower dose of lithium
potassium-sparing diuretics are also known as what?
aldosterone-inhibiting diuretics
examples of potassium spring diuretics?
Amiloride* (Midamor®)
Spironolactone* (Aldactone®)
triamterene
triamterene in combination with hydrochlorothiazide*
MOA of K-sparing diuretic?
Work in collecting ducts and distal convoluted tubules
Interfere with sodium–potassium exchange
Competitively bind to aldosterone receptors
Block resorption of sodium and water usually induced by aldosterone secretion
are K-sparing diuretics drug effects weak or strong compared with the thiazide and loop diuretics?
weak
what are the indications of potassium-sparing diuretics?
spironolactone and triamterene
- hyperaldosteroism
- htn
- reversing K loss caused by K-wasting diuretics
- certain cases of heart failure: prevention of remodelling
amiloride
-similar to spironolactone and triamterene but less effective in the long term
adverse effects of K sparing diuretics? CNS, GI, otehr
CNS: dizziness, headache
GI: cramps, n+V, diarrhea
other: urinary freq, weakness, hyperkalemia
adverse effects of spironolactone?
gynecomastia
amenorrhea
irregular mensus
postmenopausal bleeding
bc it affects prolactin levels
interactions for K-sparing diuretics?
lithium
ACE inhibitors
K supplements
NSAIDs
what are some ways of preventing potassium imbalances? for hypokalemia?
low dose of diuretics
using supplemental potassium, use potassium-sparing along w potassium-losing medications
inc food of intake of K
restrict dietary sodium intake
what are some of ways of preventing potassium imbalances? for hyperkalemia?
potassium- sparing diuretics and potassium supplements wit renal impairment
avoid excessive amounts of potassium supplments
avoid salt substitutes
maintain urine output
example of thiazide diuretics
hydrochlorothiazide
examples of thiazide-like diuretics?
metolazone
chlorthalidone
indapamide
MOA of thiazide and thiazide-like diuretics?
inhibit tubular resoption of sodium, chloride, and K ions
action primarily in the distal convoluted tubule
result in osmotic water loss
dilate the arterioles by direct relaxation
dec preload and afterload
when should thiazides not be used?
if creatinine clearance is less than 30-50 mil/min (normal is 125ml/min)
which thiazide diuretic remains effective to a creatinine clearance of 10ml/min?
metolazone
indications for thiazide and thiazide-like diuretics?
htn edematous states idiopathic hypercalciuria diabets insipidus heart failure caused by diastolic dysfunction
adverse effects of thiazide lie diuretics? CNS, GI, GU, hematological
CNS: dizziness, headache, blurred vision
GI: Anorexia, N+V, diarrhea
GU: erectile dysfunction
Hematological: jaundice, leukopenia, agranulocytosis
adverse effects for thiazide-like diuretics (cont.) integumentary
metabolic
**integumentary: urticaria, photosensitivity
metabolic: hypokalemia, glycosuria, hyperglycaemia, hyperuricemia, hypochloremic, alkalosis
when should patients take diuretics?
morning bc can’t sleep at night
what foods are high in potassium?
bananas, oranges, dates, apricots, raisins, broccoli, green beans, potatoes, tomatoes, meats, fish, wheat bread, and legumes.
what should you teach patients with diabetes if they’re taking diuretics?
** Patients with diabetes mellitus who are taking thiazide or loop diuretics should be told to monitor blood glucose and watch for elevated levels.
teaching strategies for diuretics?
Teach patients to change positions slowly and to rise slowly after sitting or lying, to prevent dizziness and fainting related to orthostatic hypotension.
**Encourage patients to keep a log of their daily weight.
Remind patients to return for follow-up visits and laboratory work
if a patient has an electrolyte imbalance d/t diuretic how might this present?
nausea, vomiting or diarrhea
what are some signs and symptoms of hypokaemia? **
**anorexia, nausea, lethargy, muscle weakness, mental confusion, and hypotension
how would hypotension or fluid loss present?
**Instruct patients to notify their primary care provider immediately if they experience rapid heart rates or syncope (reflects hypotension or fluid loss).
excessive consumption of liquorice can lead to ____in patients taking thiazides?
hypokalemia
what are some therapeutic effects?
Reduction of edema Reduction of fluid volume overload Improvement in manifestations of heart failure Reduction of hypertension Return to normal intraocular pressures
