Also indexed as: Aldactone
Spironolactone is a potassium-sparing
diuretic. Diuretics cause water loss and are used to treat a variety of conditions,
including high blood pressure, heart failure, and diseases of the kidneys and liver.
Spironolactone is available as a single agent and in a combination drug product.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
Avoid: Adverse interaction—Avoid these supplements when taking this
medication because taking them together may cause undesirable or dangerous results. |
Buchu
Cleavers
Dandelion
Gravel root
Horsetail
Juniper
Magnesium*
Uva ursi
|
Check: Other—Before taking any of these supplements or eating any of
these foods with your medication, read this article in full for details. |
Potassium
Sodium
|
| Depletion or interference |
None known
|
| Side effect reduction/prevention |
None known
|
| Supportive interaction |
None known
|
| Reduced drug
absorption/bioavailability |
None known
|
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
evidence.
Interactions with Dietary Supplements
Folic
acid
One study showed that people taking diuretics for more than six months had dramatically lower
blood levels of folic acid and higher levels of
homocysteine compared with individuals not taking diuretics.1 Homocysteine, a
toxic amino acid byproduct, has been associated with atherosclerosis. Folic acid is also an important cause
of elevated homocysteine levels. Until further information is available, people taking
diuretics for longer than six months should probably supplement with folic acid.
Magnesium
Preliminary research in animals suggests that
amiloride, a drug similar to spironolactone, may inhibit the urinary excretion of
magnesium.2 It is unknown if this same effect would occur in humans or with
spironolactone. Persons taking more than 300 mg of magnesium per day and spironolactone should
consult with a doctor as this combination may lead to potentially dangerous increases in the
level of magnesium in the body. The combination of spironolactone and hydrochlorothiazide would likely eliminate this
problem, as hydrochlorothiazide may deplete magnesium.
Potassium
As a potassium-sparing diuretic, spironolactone reduces urinary loss of potassium, which can
lead to elevated potassium levels.3 People taking spironolactone should avoid
potassium supplements, potassium-containing salt substitutes (Morton Salt Substitute, No Salt,
Lite Salt, and others), and even high-potassium foods (primarily fruit). Doctors should monitor potassium blood levels
in patients taking spironolactone to prevent problems associated with elevated potassium
levels.
However, one medication (Aldactazide) contains the combination of the potassium-sparing
drug spironolactone and the potassium-depleting drug hydrochlorothiazide. With the use of Aldactazide,
potassium excess and potassium depletion are both possible. People taking this combination
drug should have their potassium levels monitored by a doctor to determine whether their
potassium intake should be increased, reduced, or kept the same.
Sodium
Diuretics, including spironolactone, cause
increased loss of sodium in the urine. By removing sodium from the body, diuretics also cause
water to leave the body. This reduction of body water is the purpose of taking diuretics.
Therefore, there is usually no reason to replace lost sodium, although strict limitation of
salt intake in combination with the actions of diuretics can sometimes cause excessive sodium
depletion. On the other hand, people who restrict
sodium intake and in the process reduce blood pressure may need to have their dose of
diuretics lowered. People taking spironolactone should talk with their prescribing doctor
before severely restricting salt.
Interactions with Herbs
Diuretic herbs
Herbs that have a diuretic effect should be avoided when taking diuretic medications, as they
may increase the effect of these drugs and lead to possible cardiovascular side effects. These
herbs include dandelion, uva ursi,
juniper, buchu, cleavers,
horsetail, and gravel root.4
Interactions with Foods and Other Compounds
Food
Food can increase absorption of spironolactone.5 Spironolactone should be taken at
the same time and always with food or always without food, every day for best results. People
with questions about spironolactone and food should ask their prescribing doctor or
pharmacist.
References:1. Morrow LE, Grimsley EW. Long-term diuretic therapy in hypertensive
patients: effects on serum homocysteine, vitamin B6, vitamin B12, and red blood cell folate
concentrations. South Med J 1999;92:866–70.
2. Devane J, Ryan MP. The effects of amiloride and triamterene on urinary
magnesium excretion in conscious saline-loaded rats. Br J Pharmacol
1981;72:285–9.
3. Ramsay LE, Hettiarachchi J, Fraser R, Morton JJ. Amiloride,
spironolactone, and potassium chloride in thiazide-treated hypertensive patients. Clin
Pharmacol Ther 1980;27:533–43.
4. Brinker F. Herb Contraindications and Drug Interactions.
Sandy, OR: Eclectic Institute, 1997, 102–3.
5. Threlkeld DS, ed. Diuretics and Cardiovasculars, Potassium-Sparing
Diuretics, Spironolactone. In Facts and Comparisons Drug Information. St. Louis, MO:
Facts and Comparisons, Jul 1993, 138h–8j.