Diuretics (Med Chem:- 2) Notes Download, Introduction
Drugs promoting urine output are known as diuretic drugs, which refer only to those agents that act directly on the kidneys. These drugs primarily increase the excretion of water and ions like sodium (Na+), chloride (Cl-), or bicarbonates (HCO3-) from the body. Glomerular filtration, tubular reabsorption, and tubular secretion in kidneys determine the excretion of substances.
Tubular reabsorption is a process which involves active transport of electrolytes and other solutes from tubular urine to tubular cells, and then to extracellular fluid. As a result, glomerular filtration is increased. The mechanism of action of diuretic drugs also involves a decrease in tubular reabsorption.
However, these drugs have no effect on glomerular filtration rate or on the action of Anti-Diuretic Hormone (ADH) on the distal portion of nephron. Diuretics effectively treat cardiac oedema (accumulation of fluid in extra vascular tissues), especially the one which is associated with congestive heart failure.
It is also employed in the treatment of various disorders like nephrotic syndrome, diabetes insipidus, hypertension, nutritional oedema, oedema of pregnancy, and liver cirrhosis. They also decrease the intracellular and cerebrospinal fluid pressure.
5.1.2. Classification
Diuretics are classified as follows:
- Carbonic Anhydrase Inhibitors: Acetazolamide, Methazolamide, and Dichlorphenamide.
- Thiazide Derivatives:
- Chlorothiazide and Analogues
- Loop Diuretics: Furosemide, Bumetanide, and Ethacrynic acid.
- Potassium Sparing Diuretics: Amiloride, Triamterene, and Spironolactone.
- Osmotic Diuretics: Isosorbide, Mannitol, Glycerol, and Urea.
- Miscellaneous: Indapamide, Xipamide, Clopamide, Quinethazone, Metolazone, Chlorthalidone, and Clorexolone.
Subject: Medicinal Chemistry 2
Semester: Sem 5
Course: Bachelor of Pharmacy
Detailed Explanation of Diuretics
Diuretics are a class of drugs that promote the production of urine, helping the body eliminate excess water and electrolytes. They are primarily used to treat conditions like hypertension, heart failure, and edema. The mechanism of action of diuretics involves altering the kidney's handling of sodium, chloride, and water, leading to increased urine output.
There are several types of diuretics, each with a unique mechanism of action and clinical use. Carbonic anhydrase inhibitors, for example, work by inhibiting the enzyme carbonic anhydrase, which reduces the reabsorption of bicarbonate and sodium in the proximal tubule. Thiazide diuretics act on the distal convoluted tubule to inhibit sodium and chloride reabsorption, while loop diuretics inhibit the Na-K-2Cl symporter in the thick ascending limb of the loop of Henle, leading to a significant diuresis.
Potassium-sparing diuretics, on the other hand, work by either blocking sodium channels or antagonizing aldosterone receptors, thereby reducing sodium reabsorption while sparing potassium. Osmotic diuretics like mannitol increase the osmolarity of the glomerular filtrate, preventing water reabsorption and promoting diuresis.
Diuretics are essential in managing various medical conditions, but they must be used cautiously due to potential side effects like electrolyte imbalances, dehydration, and metabolic disturbances. Proper monitoring and patient education are crucial to ensure safe and effective use of these medications.
Info!
If you are the copyright owner of this document and want to report it, please visit the copyright infringement notice page to submit a report.
