Spironolactone is a potassium-sparing diuretic used to treat high blood pressure or fluid retention. As with all diuretics, spironolactone must be taken in combination with a low-sodium diet and increased water intake but may also raise potassium levels in the body. Spironolactone may also interfere with the excretion of other minerals and cause depletion of some vitamins.
Spironolactone inhibits the activity of the mineralocorticoid hormone aldosterone, which signals the body to retain sodium and water as well as excrete potassium. Spironolactone may be prescribed for hyperaldosteronism, high blood pressure or fluid retention due to heart, liver or kidney disease. Its effects on aldosterone results in the removal of retained salt and water from the body.
Spironolactone interferes with the removal of potassium by the kidneys and may interfere with the removal of magnesium and other minerals. Though sodium should be limited, it is possible for spironolactone to cause excessive loss of sodium and water. Spironolactone may cause dry mouth, nausea, thirst, dizziness, headache and fatigue that may be signs of dehydration. Spironolactone may also cause enlarged or painful breasts, irregular menstruation, erectile dysfunction or increased hair growth.
Diet on Spironolactone
You should follow a low-sodium diet while on spironolactone. Normal sodium intake is from 1,200 to 1,500 mg per day, but your doctor will instruct you on specifics. Your doctor may also direct you to limit your intake of potassium-rich foods such as fruits and vegetables to prevent elevated potassium levels. Some evidence suggests that spironolactone may prevent your body from excreting magnesium; avoid supplements containing magnesium. Spironolactone may also deplete folic acid, or vitamin B-9; be sure to take a multivitamin.
Check with your healthcare provider before taking any over-the-counter medications or dietary supplements while on spironolactone. Many supplements have diuretic activity that can raise the risk of dehydration while on spironolactone. Avoid excessive intake of alcohol or caffeine, as they also act as diuretics. Taking spironolactone with food may increase its absorption; be sure to take this medication the same way everyday.