Aldactone and blood pressure

Aldactone is the brand name for spironolactone, a potassium-sparing diuretic. Whether a blood pressure change is intended or an unwanted effect depends on why it was prescribed, the dose, hydration, other medicines and the person's underlying health.

Spironolactone blocks aldosterone, a hormone that encourages the kidneys to retain sodium and water. Passing more sodium and water can reduce circulating fluid and lower pressure, while the kidneys retain more potassium than with some other diuretics.

A lower reading is not automatically harmful. Symptoms and the individual's target matter. Light-headedness on standing, blurred vision, unusual fatigue or near-fainting can signal that pressure has fallen too far, particularly during hot weather, poor fluid intake, vomiting or diarrhoea.

Use Aldactone only on the prescribed schedule. Rise slowly from bed or a chair until you know its effect, and follow the clinician's advice about fluids and salt. Do not add potassium supplements or potassium-based salt substitutes unless the prescriber has approved them.

If home monitoring is recommended, sit quietly before checking, use a correctly fitting cuff and keep a log of readings, symptoms and dose times. Bring the record to follow-up. The clinician may also order kidney function and potassium tests, especially after a dose or medicine change.

Call the prescribing clinic promptly if repeated readings are outside the limits they gave you, or if you develop ongoing light-headedness, weakness, reduced urination, vomiting, diarrhoea, muscle cramps or palpitations. The next step may involve checking hydration, kidney function, potassium and interacting medicines.

Get urgent medical help for collapse, severe confusion, chest pain, severe shortness of breath, or a persistent abnormal heartbeat. Do not drive yourself if you feel close to fainting.

Confirm your personal blood pressure limits, when measurements should be taken, which laboratory checks are planned, and what to do if you become dehydrated. Ask the clinician to review every blood pressure medicine, anti-inflammatory pain medicine, supplement and salt substitute you use.