Compare Hydrochlorothiazide vs. Aldactone

Head-to-head comparisons of medication uses, side effects, ratings, and more.

(Hydrochlorothiazide )


Lowers blood pressure. Removes extra water from your body. Microzide (Hydrochlorothiazide (Hctz)) is a well-tolerated water pill that's often the first-choice treatment for mild high blood pressure.Removes extra water from your body. Aldactone (Spironolactone) is helpful when added to another diuretic to get rid of excess fluid in your body. Doesn't work well on its own.
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Reviews & ratings
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Reviews for Microzide (Hydrochlorothiazide (Hctz))
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137 reviews

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Side effects

The Hydrochlorothiazide FDA package insert doesn’t have numbers about how common side effects are.

More about Hydrochlorothiazide side effects »

We haven’t found good data for Aldactone side effects.

FDA side effect reports for Aldactone »
How it works
Microzide (Hydrochlorothiazide (Hctz)) is a thiazide diuretic (water pill). It works in the kidneys to make you urinate more, which removes extra water and certain electrolytes. This lowers blood pressure and swelling.Aldactone (Spironolactone) is a potassium-sparing diuretic that blocks aldosterone (a hormone) and helps the kidney get rid of excess fluids in your body.
Type of medication
Prescription only
Prescription only
Available as
  • Pill
  • Pill
Used for (click to learn more)
Risk factors for serious side effects
  • Current electrolyte imbalance
  • History of sulfa allergies
  • History of gout
  • Current kidney problems
    Detailed Microzide (Hydrochlorothiazide (Hctz)) risks & warnings »
      • Taking with alcohol
      • Taking other medicines that make you less alert
      • Current kidney problems
      • Medicine that increase potassium
      • Use of salt substitute
        Detailed Aldactone (Spironolactone) risks & warnings »
        Pregnancy category
        BFDA pregnancy category (Probably safe)

        Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

        See the FDA package insert
        CFDA pregnancy category (Weigh risks vs. benefits)

        Research studies with animals found harmful effects on unborn babies. It hasn’t been properly studied in humans. The benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

        See the FDA package insert
        No specific alcohol-related info.No specific alcohol-related info.
        No specific food-related info.No specific food-related info.
        Kidneys and liver
        • Doesn't work well in people with severe kidney problems.
        • Requires routine blood tests to check kidney function.
        • Needs to have blood tests done to monitor electrolyte levels and kidney function.
        • Aldactone (Spironolactone) can increase the amount of potassium in your body. High potassium can cause heart problems. Baseline and routine blood tests are needed to monitor your potassium and kidney function.
        No specific sex-related info.
        • You can have breast pain/swelling, irregular periods (women), or trouble with sexual performance.
        No specific sleep-related info.No specific sleep-related info.
        No specific weight-related info.No specific weight-related info.
        Upsides and benefits
        • Works well to get rid of extra fluids in your body through urination.
        • A first-choice blood pressure treatment for many people. Works especially well for African Americans.
        • Lowers the risk of heart attack and stroke.
        • Good option if you have both high blood pressure and heart failure.
        • Raises calcium levels in the body, so it can be good for people with osteoporosis to slow down bone loss and even help with new bone formation.
        • Most people have very few side effects.
        • Has a low risk of causing muscle problems due to low potassium levels in your blood.
        • More useful when taken with another diuretic that'll also help your body get rid of extra fluids.
        • Can lower blood pressure.
        • Reduces the risk of death in people with heart failure.
        Downsides and risks
        • Makes you urinate more often.
        • Doesn't work well in people with severe kidney problems.
        • Not very good at getting rid of excess fluids on its own. Should be used with another drug to help get rid of excess fluids.
        • Has many possible side effects, especially when higher doses are used.
        • Can increase the risk of tumor growth.
        • Needs to have blood tests done to monitor electrolyte levels and kidney function.
        Tips from our pharmacists for people taking the medication
        • Starts working in about 2 hours.
        • Makes you urinate more often, so avoid taking it at bedtime.
        • Can cause dizziness in the first few days.
        • Check your blood pressure 1 week after starting this medicine, and tell your doctor if it hasn't improved.
        • Tell your doctor about any dizziness, fatigue, or muscle weakness that doesn't go away.
        • Requires routine blood tests to check kidney function.
        • Can make you dizzy or cause trouble concentrating, so be careful using it until you know how the medicine affects you.
        • Don't use supplements or salt substitutes that are high in potassium.
        • You can have breast pain/swelling, irregular periods (women), or trouble with sexual performance.
        • Tell your doctor about any muscle weakness, skin changes, red or black tarry stool.
        • Can take 2 to 3 days to see full diuretic effects and 2 to 3 weeks to see blood pressure lowering effects.
        Learn more
        More about HydrochlorothiazideSide effectsReviews & ratingsAlternativesFDA package insert
        More about AldactoneSide effectsReviews & ratingsAlternativesFDA package insert