GENERIC NAME: metolazone
BRAND NAME: Zaroxolyn
DISCONTINUED BRANDS: Diulo, Mykrox
DRUG CLASS AND MECHANISM: Metolazone is a diuretic ("water pill") used in the treatment of high blood pressure and fluid accumulation. It works by blocking salt and fluid retention by the kidneys, thereby increasing urinary output of salt and water (diuresis). Although it is not a true thiazide, metolazone is chemically related to the thiazide class of diuretics (for example, chlorthalidone [Hygroton], hydrochlorothiazide), and works in a similar manner. Zaroxolyn is the original formulation of metolazone, and Diulo is similar. The absorption of these two drugs is relatively incomplete. Mykrox has more complete absorption. Therefore, less Mykrox needs to be given to have the same effects as a larger dose of Zaroxolyn or Diulo. Metolazone was approved by the FDA in 1973.
PRESCRIBED FOR: Metolazone is used in the treatment of high blood pressure and edema (fluid retention).
SIDE EFFECTS: Metolazone generally is well tolerated. Common side effects of metolazone are:
- Hypokalemia (low blood potassium),
- (low blood sodium), and
- hypomagnesemia (low blood magnesium).
- Hypercalcemia (high blood calcium)
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