Loop diuretics Nursing Considerations, Implications & Drug Study
LOOP DIURETICS
GENERAL DESCRIPTION
Loop diuretics are the most efficacious diuretics agents available because diuretic effects of loop diuretics are not affected with the development of acidosis in the body like other diuretic agents. Furosemide and ethacrynic acid are the prototypes of loop diuretics. Loop diuretics usually used in heart failure and hypertension. Loop diuretics increase calcium secretion unlike other diuretic agents.
EXAMPLE: Furosemide, Ethacrynic acid, Bumetanide, Torsemide
FUROSEMIDE
- GENERIC NAME: Frusemide
- BRAND NAME: Lasix, Fusid. Lasilix, Furantril, Discoid
GENERAL DESCRIPTION
Furosemide is sulphonamide loop diuretics. It is more affected in patient with impaired renal function than thiazide diuretics which are more affected in patients with normal renal function.
MECHANISM OF ACTION
Furosemide inhibits the NKCC2 (Na+ Cl-2 K+ co-transporter) that is located in the Thick ascending loop of Henle. Furosemide direct inhibit the chloride-binding site and thus stop the transport mechanism of NKCC2 in the lumen. This action stop the transport of sodium and chloride outside the lumen and thus reduce the hypertonicity around the lumen and increase solute concentration inside the lumen. This cause increase in urination with the loss of sodium. Due to hypo tonicity around the lumen positive potential generates and cause Ca2+ and Mg2+ excretion. In addition to the diuretic effect, furosemide also has direct effects on blood flow through vasodilation and increases renal blood flow.
PHARMACOKINETICS
Furosemide absorbs rapidly in the body. It is 95% plasma protein binding. Furosemide eliminated through glomerular filtration and tubular secretion. The duration of effects of furosemide is 2-4 hours
INDICATIONS
- Acute pulmonary edema
- Edema caused by CHF or renal insufficiency
- Hypertension
- Acute hypercalcemia
- Hyperkalemia
- Anion overdose.
CONTRAINDICATIONS
- Hyponatremia
- Hypovolemia
- Anuria
- Diabetes Mellitus
- Gout
- High levels of uric acid
- Pancreatitis
- Electrolyte imbalance
SIDE EFFECTS & ADVERSE EFFECTS
- Hypersensitivity
- Hypokalemic metabolic acidosis
- Ototoxicity
- Hyperuricemia (causes Gout)
- Hypomagnesemia
DRUG INTERACTION
- Furosemide increase the nephrotoxicity of first-generation cephalosporin e.g. cephaloridine
- Furosemide increase aminoglycoside toxicity when given concurrent.
- Lithium reabsorption is reduced when given with furosemide and thus lithium dose adjustment is needed.
- Probenecid decrease the renal clearance of furosemide but not alter the diuretic effects of furosemide.
- NSAIDs reduced the antihypertensive and diuretic effects of furosemide when given concurrently. Furosemide increase the risk of NSAIDs induced acute renal failure and may intensify CHF.
- Furosemide when given with food decrease the bioavailability of furosemide in the body and reduce diuretic effects of furosemide.
- Aspirin may reduce the diuretic and vasodilation effects of furosemide when given concurrent.
- Phenytoin reduce the diuretic effect as much as 50% of furosemide.
Colestyramine and colestipol reduce the absorption and diuretic effects of furosemide.
Nursing Implications & considerations: PRE & POST NURSING CARE
- Ask patient if he is taken digoxin because digoxin toxicity will be increased due to potassium depleting effect
- Obtain complete health history (Electrolyte balance & renal function)
- Obtain vital signs with the baseline values specially Blood pressure
- Find out patient’s medication history including alcohol and nicotine consumption to avoid drug interaction
- Determine possible drug allergies of patient.
- Obtain blood and urine specimen for laboratory analysis
- Observe for any change in consciousness, dizziness, fatigue, postural hypotension
- Monitor for fluid intake by measuring intake, output and daily weight.
- Monitor laboratory values specially potassium and sodium levels, BUN, Serum Uric acid.
- Monitor hearing and vision (because some loop diuretics are ototoxic & thiazide diuretic produce visual change by increasing digoxin level)
- Assess patient for any skin rash and discontinue after appearing any rash and consult HP
Nursing Implications & considerations: PATIENT EDUCATION
- Contact doctor if weight gain in a day or two
- Explain the right use of diuretics with dosage
- Report any visible s/s of proximal edema, SOB, potential sign of Heart Failure or Pulmonary edema
- Report immediate if feeling dizzy or change in consciousness
- Advise them to change position slowly to avoid postural hypotension
- Monitor BP as specified by the HP
- Mention possible side effects that can cause by the use of diuretics such as dry mouth, increase in urination.
- Take potassium containing diet if using loop or thiazide diuretics
- Ask health care professional before taking any vitamin/minerals or other supplements