0071483446.pdf

(^362) CHAPTER 19 Cardiac Circulatory Medications
and magnesium are lost. Loop or high-ceiling diuretics have little effect on blood
sugar, but increase the uric acid level.
Loop or high-ceiling diuretics are potent and cause marked depletion of water
and electrolytes. They are more potent than thiazides and two to three times
more effective when inhibiting reabsorption of sodium. However, loop or high-
ceiling diuretics are less effective as antihypertensive agents.
Loop or high-ceiling diuretics can increase renal blood flow up to 40%. This
drug is commonly the choice for patients who have decreased kidney function
or end-stage renal disease.
Loop or high-ceiling diuretics cause excretion of calcium and have a great
saluretic (sodium-losing) affect that causes rapid diuresis, decreases vascular
fluid volume, and decreased cardiac output and blood pressure.
Loop or high-ceiling diuretics causes a vasodilatory effect and increase renal
blood flow before diuresis. The most common side effects are fluid and electro-
lyte imbalances such as hypokalemia, hyponatremia, hypocalcemia, hypomag-
nesemia, and hypochloremia. Hypochloremic metabolic alkalosis may result.
Orthostatic hypotension can also occur. Thrombocytopenia, skin disturbances,
and transient deafness are seen rarely. Prolonged use can cause thiamine defi-
ciency.
A list of loop diuretic drugs is provided in the Appendix. Detailed tables show
doses, recommendations, expectations, side effects, contraindications, and more;
available on the book’s Web site (see URL in Appendix).
OSMOTIC DIURETICS
Osmotic diuretics increase the concentration (osmolality) of the plasma and fluid
in the renal tubules. Sodium, chloride, potassium (to a lesser degree), and water
are excreted. Osmotic diuretics are used to prevent kidney failure, decrease
intracranial pressure (ICP) (cerebral edema), and decrease intraocular pressure
(IOP) as is the case with glaucoma.
Mannitol is a potent potassium-wasting osmotic diuretic used in emergencies
to treat intraocular pressure. Mannitol is also used with cisplatin and carboplatin
in cancer chemotherapy to induce a frank diuresis for decreased side effects
of treatment.
Mannitol is the most frequently prescribed osmotic diuretic. The side effects
and adverse reactions include fluid and electrolyte imbalance, pulmonary edema
from rapid shift of fluids, nausea, vomiting, tachycardia from rapid fluid loss,
and acidosis.