the use of extremely high doses. The injectable form of the drug must be stored at
controlled room temperature and should not be used if the solution is yellow. The oral
solution and tablet preparations should be dispensed in light--resistant containers.
Other loop diuretics include bumetanide (Bumex), ethacrynic acid
(Edecrin), and torsemide (Demadex).
f. Inhibition of Sodium and Chloride Reabsorption Diuretics. The
mechanism of action of this type is very similar to the thiazide diuretics. That is, drugs
of this category inhibit sodium and chloride reabsorption that results in the increased
excretion of sodium, chloride, and water.
Chlorthalidone (Hygroton). This agent differs from the thiazide diuretics only
in chemical structure. Chlorthalidone's pharmacological action is indistinguishable from
the thiazide diuretics. Chlorthalidone is used in the management of hypertension--either
as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in
patients who have the more severe forms of hypertension. It is also used as adjunctive
therapy in the treatment of edema associated with congestive heart failure, hepatic
cirrhosis, and various forms of renal dysfunctions. Refer to the information on
hydrochlorothiazide for side effect information.
g. Combination Diuretics (Potassium-Sparing and Thiazide Diuretic
Combination). The potassium-sparing and thiazide diuretics have different but
complementary mechanisms and sites of action. Therefore, when given together they
produce additive diuretic and antihypertensive effects. The thiazide component blocks
the reabsorption of sodium and chloride ions and thus increases the quantity of sodium
traversing the distal tubule and the volume of water excreted in the urine. This
characteristically induces potassium loss. The potassium-sparing component inhibits
the reabsorption of sodium in exchange for potassium and hydrogen ions at the distal
tubule, so that sodium excretion is greatly favored and the excess loss of potassium, as
well as hydrogen and chloride ions induced by the thiazide, is reduced.
(1) Aldactazide (combination of spironolactone and hydrochlorothiazide).
This drug is used for the treatment of edema associated with congestive heart failure,
cirrhosis of the liver and ascites and for essential hypertension.
(2) Dyazide (combination of triamterene and hydrochlorothiazide). This
agent is used in the treatment of edema associated with congestive heart failure,
cirrhosis of the liver, and hypertension. The usual dosage of this product from 1 to 2
capsules taken twice daily after meals. The patient should take no more than four
capsules per day. The side effects associated with this agent include hyperglycemia,
hyperuricemia, and gastrointestinal disturbances. Each Dyazide capsule contains 37.5
milligrams of triamterene and 25 milligrams of hydrochlorothiazide. There are other
combinations of these diuretics available as generics or as Maxide (75/50; 50/25).
One must be very careful and doublecheck the active ingredients to ensure that the
correct product is dispensed.