Thiazide diuretics are a family of drugs that remove water from the body. They are referred
to as potassium-depleting because they cause the body to lose potassium as well as water. Potassium-depleting
diuretics also cause the body to lose
magnesium. Thiazide diuretics are used to lower blood pressure in people with high blood pressure. Diuretics are also used to reduce water accumulation caused by other diseases.
Helpful Products
Try these helpful products which may be beneficial if taken with this medicine
Potassium
To avoid depleting potassium, which can lead to muscle cramps, twitches, and an irregular
heartbeat, take a potassium supplement and eat more fruits (especially bananas), vegetables,
and juices
Magnesium
To avoid depleting magnesium, which can lead to weakness, muscle tremors, twitches, and
mental dullness, supplement with 300 to 600 mg per day, or eat more nuts, grains, and
beans
Folic acid
Preliminary research suggests that this medicine might deplete this nutrient, so
supplementing with 400 mcg per day may help improve blood levels
These recommendations are not comprehensive and are not intended to
replace the advice of your doctor or pharmacist. Continue reading the full article for more
information on interactions with vitamins, herbs, and foods.
Thiazide diuretics are also combined with other drugs to treat various conditions.
The information in this article pertains to thiazide diuretics in general. The interactions
reported here may not apply to all the Also Indexed As terms. Talk to your doctor or
pharmacist if you are taking any of these drugs.
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.
May Be Beneficial:Depletion or
interference—The medication may deplete or interfere with the absorption or
function of the nutrient. Taking these nutrients may help replenish them.
Folic acid *
Magnesium
Potassium
Zinc
Avoid:Adverse interaction—Avoid these supplements when taking this
medication because taking them together may cause undesirable or dangerous results.
Alder Buckthorn*
Buchu
Buckthorn*
Cleavers
Dandelion
Digitalis
Ginkgo biloba*
Gravel root
Horsetail
Juniper
Licorice
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.
Calcium
Sodium
Vitamin D
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
Calcium
Thiazide diuretics decrease calcium loss in the urine due to actions on the
kidneys.1 As a result, it may be less important for some people taking thiazide
diuretics to supplement calcium than it is for other people.
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.2 Homocysteine, a
toxic amino acid byproduct, has been associated with atherosclerosis. Until further information is
available, people taking diuretics for longer than six months should probably supplement with
folic acid.
Magnesium and Potassium
Potassium-depleting diuretics, including thiazide diuretics, cause the body to lose potassium;
they may also cause cellular magnesium depletion,3 although this deficiency may not
be reflected by a low blood level of magnesium.4 Magnesium loss induced by
potassium-depleting diuretics can cause additional potassium loss. Until more is known, it has
been suggested that people taking potassium-depleting diuretics, including thiazide diuretics,
should supplement both potassium and magnesium.5
People taking thiazide diuretics should be monitored by their prescribing doctor, who will
prescribe potassium supplements if needed. Such supplementation is particularly critical
before surgery in patients with a history of heart
disease. In a preliminary study, people with low blood levels of potassium (in part
related to diuretic use) had a higher incidence of serious problems resulting from surgery
(including death) compared with those having normal potassium levels.6 A
double-blind trial showed that thiazide diuretic use led to a reduction in blood levels of
potassium in some participants. Those experiencing decreased potassium levels were also more
likely to experience cardiovascular events, such as heart attacks, stroke,
heart failure, aneurysm, and sudden
cardiac death.7Fruit is high in
potassium, and increasing fruit intake (especially bananas) is another way of supplementing
potassium.
Magnesium supplementation for people taking
thiazide diuretics is typically 300–600 mg per day, though higher amounts (over 800 mg
per day) have been reported in a controlled study to reduce side effects of
thiazides.8 Combining supplementation of both potassium and magnesium has been reported to correct
abnormally low blood levels of potassium and also to protect against excessive loss of
magnesium.9
Vitamin
D
The reduction in urinary calcium loss resulting from treatment with thiazide diuretics is due
primarily to changes in kidney function and may also be due, in part, to changes in vitamin D
metabolism.10 However, there is no evidence to suggest that people taking diuretics
have different requirements for vitamin D.
Zinc
Thiazide diuretics can increase urinary zinc loss.11
Sodium
Diuretics, including thiazide diuretics, 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.
Interactions with Herbs
Herbs that have a diuretic effect should be avoided when taking diuretic medications, as
they may enhance 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.12
Alder Buckthorn,
Buckthorn(Rhamnus catartica, Rhamnus
frangula, Frangula alnus)
Use buckthorn or alder buckthorn for more than ten days consecutively may cause a loss of
electrolytes (especially the mineral potassium). Medications that also cause potassium loss,
such as some diuretics, should be used with caution when taking buckthorn or alder
buckthorn.13
Digitalis (Digitalis purpurea)
Digitalis refers to a family of plants commonly called foxglove, which contains digitalis
glycosides, chemicals with actions and toxicities similar to the prescription drug digoxin. Thiazide diuretics can increase the risk of
digitalis-induced heart disturbances.14 Thiazide diuretics and digitalis-containing
products should be used only under the direct supervision of a doctor trained in their
use.
Ginkgo
biloba
One case was reported in which ginkgo use was associated with high blood pressure in a person treated with a
thiazide diuretic.15 Ginkgo was not proven to be the cause of this reaction.
Licorice(Glycyrrhiza glabra)
Licorice may increase the side effects of potassium-depleting diuretics, including thiazide
diuretics.16 Thiazide diuretics and licorice should be used together only under
careful medical supervision. At the time of this writing, no evidence was found of
interactions between deglycyrrhizinated licorice (DGL) and any diuretic was found in the
medical literature.
Interactions with Foods and Other Compounds
Food
Thiazide diuretics may be taken with food to avoid stomach upset.17
References (To view, roll mouse over the "References" heading; to hide, click on the heading)
1. Threlkeld DS, ed. Diuretics and Cardiovasculars, Thiazides and Related
Diuretics. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Jul 1993, 135a–7c.
2. 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.
3. Martin B, Milligan K. Diuretic-associated hypomagnesiumia in the
elderly. Arch Intern Med 1987;147:1768–71.
4. Kroenke K, Wood DR, Hanley JF. The value of serum magnesium
determination in hypertensive patients receiving diuretics. Arch Intern Med
1987;147:1553–6.
5. Whang R, Whang DD, Ryan MP. Refractory potassium repletion—a
consequence of magnesium deficiency. Arch Intern Med 1992;152:40–5.
6. Wahr JA, Parks R, Boisvert D, et al. Preoperative serum potassium
levels and perioperative outcomes in cardiac surgery patients. JAMA
1999;281:2203–10.
7. Franse LV, Pahor M, Di Bari M, et al. Hypokalemia associated with
diuretic use and cardiovascular events in the Systolic Hypertension in the Elderly Program.
Hypertension 2000;35:1025–30.
8. Ruml LA, Gonzalez G, Taylor R, et al. Effect of varying doses of
potassium-magnesium citrate on thiazide-induced hypokalemia and magnesium loss. Am J
Ther 1999;6:45–50.
9. Ruml LA, Pak CYO. Effect of potassium magnesium citrate on
thiazide-induced hypokalemia and magnesium loss. Am J Kidney Dis
1999;34:107–13.
10. Riis B, Christiansen C. Actions of thiazide on vitamin D metabolism:
A controlled therapeutic trial in normal women early in the postmenopause. Metabolism
1985;34:421–4.
11. Reyes AJ, Leary WP, Lockett CJ, et al. Diuretics and zinc. S Afr
Med J 1982;62:373–5.
12. Brinker F. Herb Contraindications and Drug Interactions.
Sandy, OR: Eclectic Institute, 1997, 102–3.
13. European Scientific Cooperative on Phytotherapy (ESCOP). Frangulae
cortex, frangula bark. Monographs on the Medicinal Uses of Plant Drugs. Exeter, UK:
University of Exeter, Centre for Complementary Health Studies, 1997.
14. Threlkeld DS, ed. Diuretics and Cardiovasculars, Thiazides and
Related Diuretics. In Facts and Comparisons Drug Information. St. Louis, MO: Facts
and Comparisons, Apr 1993, 135a–7c.
15. Shaw D et al. Traditional remedies and food supplements: a 5-year
toxicological study (1991–1995). Drug Safety 1997;17:342–56.
16. Shintani S, Murase H, Tsukagoshi H, Shiigai T. Glycyrrhizin
(licorice)-induced hypokalemic myopathy. Report of two cases and review of the literature.
Eur Neurol 1992;32:44–51.
17. Threlkeld DS, ed. Diuretics and Cardiovasculars, Thiazides and
Related Diuretics. In Facts and Comparisons Drug Information. St. Louis, MO: Facts
and Comparisons, Jul 1993, 135a–7c.
The information presented in Aisle7 is for informational purposes only.
It is based on scientific studies (human, animal, or in vitro), clinical experience,
or traditional usage as cited in each article. The results reported may not necessarily occur
in all individuals. For many of the conditions discussed, treatment with prescription or over
the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist
for any health problem and before using any supplements or before making any changes in
prescribed medications. Information expires February 2010.
