All About Antihypertensive Series 4 – Diuretics

Hello all nursing students there,

This is the fourth topic in All About Antihypertensive Series… You can read other topics in this series here… Diuretics are primarily those drugs help in the diuresis or increased production of urine. These drugs mainly affect the renal mechanism for tubular secretion and reabsorption of water and electrolytes. Diuretics are classified as follows

Classification and Examples

Thiazide and Thiazide-like diuretics

  • Chlorothiazide
  • Hydrochlorothiazide
  • Metolazone
  • Chlorthalidone
  • Indapamide

Last two are the examples for Thiazide-like diuretics.

Loop Diuretics

  • Furosemide
  • Torsemide
  • Bumetanide

Potassium-sparing Diuretics

  • Amiloride
  • Spironolactone
  • Triamterene

Osmotic Diuretics

  • Mannitol

Carbonic Anhydrase Inhibitors

  • Acetazolamide
  • Methazolamide

Mechanism of  action

The action of the diuretics varies depending on the agents. Generally, all affect on the renal mechanism for tubular secretion and reabsorption and enhance the selective excretion of various electrolytes and water.

In the management of hypertension, the diuretic of choice is the Thiazide and the Thiazide-like diuretics and the loop diuretics. Other groups have only a weak Antihypertensive property and are used in different conditions too. For instance, potassium-sparing diuretics are to conserve potassium in patients receiving  Thiazide and loop diuretics, whereas, osmotic diuretics are a major choice in treating cerebral edema.

Contraindications

  • Hypersensitivity
  • Sulfa agents allergies
  • Gout
  • Pregnancy

Adverse effects

Thiazide and loop diuretics have the following side effects

  • Orthostatic hypotension
  • Metabolic alkalosis
  • Ototoxicity
  • They decrease levels of Na+, K+, and Mg+
  • They increase the levels of serum calcium, uric acid, glucose, cholesterol, and triglycerides

potassium-sparing diuretics specially Triamterene has the following side effects

  • Nausea
  • Flatulence
  • Skin Rashes
  • Nephrolithiasis

Drug Interactions

  • Additive hypokalemia with CORTICOSTEROIDS
  • Additive Hypotension with OTHER ANTIHYPERTENSIVES
  • Hyperkalemia with potassium-sparing diuretics and  ACEIs, ARBs, or Aliskiren
  • Lithium toxicity with potassium-sparing diuretics and LITHIUM as the combo reduce lithium excretion.

Nursing considerations

  • Fluid status must be monitored by, daily weight checks, maintenance of I/O chart, and assessment for any edema, lung sounds, skin turgor, and condition of the mucous membrane.
  • Assess any electrolyte imbalances by assessing for anorexia, muscle weakness, numbness, confusion, excessive thirst
  • Monitor pulse and BP before and during the therapy
  • Monitor lab values for electrolytes, especially K+, blood glucose, BUN, serum uric acid.
  • Administer oral diuretics in the morning to prevent sleep disturbances
  • Instruct to continue the Antihypertensive dose as prescribed even if the symptoms relieved.
  • Advise to change positions slowly to manage Orthostatic hypotension
  • Instruct to monitor weight weekly and to report significant changes.
  • Teach self-monitoring of pulse and BP
  • Caution on photosensitive reactions -instruct to use protective clothing and to use protective sunscreens

Hope you find it easy to follow and useful. Give your suggestions for further improvement…

Have a concentrated study time…

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