Tuesday, August 14, 2018

What are the Osmotic Diuretics Drugs? Uses, Side Effects, and Drug Interactions

Mannitol, glycerin (also called glycerol, glycerine), isosorbide, and urea, are examples of osmotic diuretics drugs. However, only mannitol is used for its diuretic actions. Osmotic diuretics increase the osmotic pressure of the glomerular filtrate, which inhibits the reabsorption of sodium and water and resulting in excretion of sodium, chloride, potassium (lesser degree), and water.
Mannitol is inadequately absorbed by the gastrointestinal tract, and when given by mouth, it causes osmotic diarrhea rather than diuresis. For systemic effect, mannitol must be administered IV only.

Uses

Osmotic diuretics drugs (e.g., mannitol) are mostly used to decrease intracranial pressure, intraocular pressure before
ophthalmologic procedures and to promote prompt removal of renal toxins.  Osmotic diuretics are also prescribed for
cerebral edema, glaucoma, and patients with acute renal failure due to shock, trauma, and drug toxicities.

Side Effects Of Osmotic Diuretics

Osmotic agents can produce the following side effects:
•    Extracellular volume expansion
•    Electrolyte and  fluid imbalance
•    Dehydration - Excessive administration of osmotic agents without fluid replacement can lead to dehydration.
•    Severe pulmonary edema
•    CNS symptoms, including a headache, nausea, vomiting, giddiness, and mental confusion
•    Tachycardia, high blood pressure, and hypotension
•    Hypersensitivity reactions

Drug interactions

No significant drug interactions are identified to be associated with osmotic diuretics.

Important Points

1.    Mannitol is available only as an IV administration dosage. 
2.    Mannitol does not easily cross the blood-brain barrier.


References: 

Sunday, August 12, 2018

What are the Potassium-sparing diuretics?

Potassium-sparing diuretics include amiloride, eplerenone, triamterene, and spironolactone; they are weak diuretics and decrease potassium excretion and increase sodium excretion through urine. Potassium-sparing diuretics do not require potassium supplements, which are required with potassium-depleting diuretics such as thiazide or thiazide-like diuretics. These drugs are occasionally prescribed alone and are not recommended for first-line diuretic therapy.
Potassium sparing diuretics drugs list

Potassium-Sparing Diuretics Drugs

•    Amiloride
•    Eplerenone
•    Spironolactone
•    Triamterene

Side Effects Potassium-Sparing Diuretics

•    Hyperkalaemia - High potassium level in the blood due to diminished urine potassium loss. Hyperkalaemia is especially
likely in patients with weakened renal function and in the elderly peoples.
•    Hyponatremia - Low level of sodium in the blood occurs when prescribed with thiazide or thiazide-like diuretics,
particularly in the elderly patients.
•    Nausea and vomiting
•    Dehydration
•    Severe weight loss
•    Fatigue
•    Gynecomastia with spironolactone
•    Low Blood Pressure (Hypotension)

Important Points

•    Use of potassium-sparing diuretics is more beneficial than the use of potassium supplements and has the extra advantage of improving blood pressure control.
•    Potassium-sparing diuretics are weak diuretics drugs but are effective antihypertensive agents mainly in low-renin (salt-dependent) high blood pressure.

References: 
https://www.ncbi.nlm.nih.gov/pubmed/2455308  (accessed on August 10, 2018) 
https://www.cvpharmacology.com/diuretic/diureticsn  (accessed on August 10, 2018)

Saturday, August 11, 2018

What are the loop diuretics? Uses, Side Effects, and Contraindications

Loop diuretics are the most commonly used and potent diuretics drug. They are more effective than thiazide diuretics. Loop diuretics include torsemide,  furosemide, bumetanide, and ethacrynic acid. Furosemide and torsemide are the most commonly used loop diuretics in India. Intravenous administration of furosemide to patients with pulmonary edema caused by acute heart failure produces a therapeutically beneficial vasodilator effect before the onset of diuresis. After taking furosemide by mouth, increased production of urine (diuresis) occurs within one hour but continues for only about four hours.
loop diuretics drugs list image

Uses

Loop diuretics are mainly used to treat edema associated with congestive heart failure, chronic renal failure, including nephrotic syndrome, liver cirrhosis, acute and chronic hyperkalemia, and acute pulmonary edema. They are also the drugs of choice for the treatment of hypertension if the response to thiazides is insufficient, but the short duration of action of loop diuretics is a disadvantage in this situation. A less common but significant application is in the treatment of severe hypercalcemia and halide poisoning.

How It Works

They enhance excretion of sodium, potassium, chloride,  by direct action at the ascending loop of Henle, producing a diuretic effect.

Side Effects

The most common side effects of loop diuretics are:
•    Hypokalemia  (Low level of potassium in the blood)
•    Hyponatremia (Low level of sodium in the blood)
•    Hyperuricaemia
•    Acute Hypovolemia
•    Increased renin production
•    Gout
•    Electrolyte and  fluid imbalance
•    Low blood pressure (Hypotension)
•    Hyperglycemia
•    Ototoxicity
•    Vertigo
•    Blurred vision
•    Rash
•    Urticaria
•    Pruritus
•    Photosensitivity
•    Headache
•    Muscle cramps
•    Mental confusion
•    Dizziness

Contraindications and Cautions

The administration of loop diuretics should be avoided in the following conditions:
•    Hypokalemia (low potassium level in the blood)
•    Hyponatremia (Low sodium level in the blood)
•    Renal failure due to nephrotoxic drugs (e.g. aminoglycosides, amphotericin, NSAIDs, and rifampicin)
•    Comatose patients with liver cirrhosis
•    Hypovolemia
•    Anuria



References
https://link.springer.com/article/10.2165/00003495-199100413-00009 (accessed on August 10, 2018) 
https://livertox.nlm.nih.gov/LoopDiuretics.htm (accessed on August 10, 2018) 
https://www.ncbi.nlm.nih.gov/pubmed/1712711 (accessed on July 30, 2018)

Tuesday, August 7, 2018

What Are the Diuretics Drug? Types, Uses, and Contraindications

Diuretics are drugs that prevent water and sodium reabsorption from the kidney tubules, resulting in increased urine flow, lower blood pressure and a reduction in peripheral and pulmonary edema.

Types Of Diuretics

Diuretics are classified into five categories according to their action. These are:
•    Loop or high-ceiling: furosemide, bumetanide, torasemide, ethacrynic acid
•    Potassium-sparing: amiloride, eplerenone, spironolactone, triamterene
•    Thiazide and thiazide-like: chlorothiazide, chlorthalidone, hydrochlorothiazide, clopamide, indapamide
•    Carbonic anhydrase inhibitor: acetazolamide, dichlorphenamide, methazolamide
•    Osmotic diuretics: mannitol, urea, glycerin, isosorbide.
types of diuretics drugs image

Contraindications

Diuretics should not be used in the in patients with known hypersensitivity to the drugs, severe dehydration, severe liver or kidney dysfunction, electrolyte imbalances, and anuria (failure of the kidneys to produce urine).
The potassium-sparing diuretics should not be given in cases with hyperkalemia and are not recommended for children. Mannitol (an osmotic diuretic) is contraindicated in patients with active intracranial hemorrhage (except during craniotomy).

Important Points

• If diuretic prescribed for high blood pressure, a low-sodium intake may be directed by the doctor.
• Non-steroidal anti-inflammatory drugs (NSAIDs) can inhibit the diuretic effectiveness in impaired kidney function.
• Diuretics drugs will not improve the swelling of feet and hands in pregnant women that some women have during pregnancy.

References
https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0025451/ (accessed on August 03, 2018)
https://www.ncbi.nlm.nih.gov/pubmed/20095917 (accessed on August 03, 2018)
FRANK J, BARTON S. (2017). (Pharmacology and Therapeutics for Dentistry). St. Louis, Missouri : Elsevier, Inc. (accessed on August 03, 2018)