Hydrochlorothiazide, a diuretic, treats disorders with symptoms of fluid retention and high blood pressure such as kidney conditions, congestive heart failure and cirrhosis of the liver. Hydrochlorothiazide gradually lowers and controls blood pressure effectively, but does not cure high blood pressure. Consequently it must be taken regularly and continued even after you feel well. One significant and recurrent issue with hydrochlorothiazide is potassium depletion, possibly requiring prescription potassium supplements or the addition of a potassium-sparing diuretic.
Hydrochlorothiazide boosts sodium and water excretion by acting in the kidneys to hinder reabsorption of sodium and chloride. This triggers the renin-angiotensin-aldosterone system from the adrenal glands situated on top of the kidneys. Renin and angiotensin act to lower blood pressure. The key word for potassium loss is aldosterone, an adrenal hormone, which controls sodium and water balance by excreting potassium and holding sodium and water. This system results in lower blood pressure, decreased water retention through increased urine production and potential potassium loss.
Management of the loss of potassium from hydrochlorothiazide includes a potassium-rich diet and adding a potassium-sparing diuretic such as spironolactone or triamterene. Elimination of over-the-counter medications and herbs that interfere with hydrochlorothiazide action can prevent potassium losses. Potassium-rich foods, including fruits such as tomatoes, bananas, apricots and dates, help to replace losses. Prescription potassium supplements under medical supervision are necessary when dietary and medication dosage manipulation does not stabilize potassium levels.
Additional Potassium Losses
Some medications and herbs can cause additional losses of potassium when used with hydrochlorothiazide. The medications include insulin, laxatives, steroids, amphotericin B, antacids, fluconazole and theophylline. The addition of other potassium-depleting diuretics such as furosemide, bumetanide, ethacrynic acid and torsemide cause severe chemical abnormalities and serious body fluid losses. Some herbs, such as dandelion and licorice, interfere with diuretic action or increase side effects and potassium losses.
Hydrochlorothiazide is not recommended if you have difficulties urinating or are allergic to sulfa drugs. Tell your physician about all of your medications, including herbs and over-the-counter medications. Refrain from using alcohol, as it increases hydrochlorothiazide side effects. A high salt intake lessens the effect of hydrochlorothiazide and causes water retention. Dehydration and too much sweating cause a loss of body fluids and might potentiate a drop in blood pressure. Illnesses that include vomiting and diarrhea can add to potassium depletion.
Hydrochlorothiazide might cause diarrhea, decreased appetite, stomach upset and irritation, general weakness, abdominal cramps and low blood pressure. Taking hydrochlorothiazide early in the morning alleviates frequent nightly urination. Symptoms of potassium depletion by hydrochlorothiazide include extreme thirst, heart irregularities, muscle cramping and pain. The elderly are especially vulnerable to an exaggerated response to diuretics with excessive urination and require close monitoring to detect chemical imbalances.
- California Pacific Medical Center: Thiazide Diuretics
- "Cardiovascular Pharmacology Concepts"; Diuretics; Richard E. Klabunde; 2009
- PDR Health: Hydrochlorothiazide
- "Nursing 2007 Drug Handbook"; 2007
- University of Maryland Medical Center: Possible Interactions with: Potassium
- "Current Medical Diagnosis & Treatment"; Stephen J. McPhee and Maxine A. Papadakis; 2008