Chlorthalidone

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Jul 26, 2022

Warnings


Chlorthalidone Risks, Warnings, and Complications


Chlorthalidone can cause serious health problems in certain groups of people. Talk to your doctor or pharmacist about other treatment options if you are at high risk of complications from chlorthalidone.

  • ELECTROLYTE ABNORMALITIES: Chlorthalidone helps the kidneys get rid of more salt and water in the body. This can lead to a loss of electrolytes like serum potassium, sodium, and magnesium. The resultant electrolyte imbalance can lead to health complications. Keep all your laboratory appointments while taking chlorthalidone. Your healthcare professional may order blood tests to keep an eye on your electrolyte levels.

  • LOW BLOOD PRESSURE: Chlorthalidone can cause dizziness or lightheadedness due to low blood pressure. The risk is higher if you are taking other medications that also cause dizziness or if you drink alcohol. Arise slowly from a sitting or lying position while on chlorthalidone. Tell your healthcare professional if you feel dizzy.

  • RISK OF GOUT ATTACKS: Chlorthalidone can lead to higher levels of uric acid and an increased risk of gout attacks. Tell your healthcare professional if you have a history of gout before starting chlorthalidone.

  • INCREASED BLOOD SUGAR LEVELS: Chlorthalidone can increase blood glucose levels. If you notice that your blood sugars are higher while on chlorthalidone, call your doctor. Your doctor may recommend dose adjustment of your diabetes medication or chlorthalidone or choose another antihypertensive drug.

  • REDUCED KIDNEY FUNCTION: Chlorthalidone oral tablet works by helping the kidneys get rid of excess salt and water in the body. In people with kidney disease such as azotemia or acute kidney failure, chlorthalidone can cause the kidneys to work too hard. Tell your health care professional if you have a history of kidney problems before starting chlorthalidone.

  • CAUTIOUS USE IN PATIENTS WITH LIVER DISEASE: Chlorthalidone should be used with caution in people with liver problems since it can lead to changes in the body’s chemistry and increase the risk of hepatic coma. Tell your health care professional if you have a history of liver disease before starting chlorthalidone.

If you are at high risk of complications from chlorthalidone, discuss other treatment options with your healthcare professional.

Precautions Before Starting Chlorthalidone

Tell your doctor if you are allergic to chlorthalidone, other sulfa drugs, or any other medications. 

Give your healthcare provider a complete medical history. Chlorthalidone may not be right for people with certain medical problems, such as diabetes, liver disease, kidney disease, gout, thyroid disease, or parathyroid disease.

Give your healthcare professional a complete list of medications, including prescription drugs, over-the-counter medicines, vitamins, supplements, and herbal products. This can help avoid possible drug interactions.

Older adults (age 65 years and above) should talk to their healthcare professional about the safety of chlorthalidone treatment, dosing modifications, etc. Health care professionals may prescribe this medication at a lower dose for older adults.

Tell your doctor if you are pregnant, could be pregnant, are planning a pregnancy, or are breastfeeding.

Precautions During Use of Chlorthalidone

Keep all your appointments while on chlorthalidone diuretic therapy. Your healthcare professional may want to order certain blood tests to check for electrolyte disturbances, uric acid levels, blood sugar levels, and fluid status.

Tell your doctor immediately if you become pregnant while on chlorthalidone. 

Tell all your doctors you are taking chlorthalidone before any surgery, including dental procedures.

Chlorthalidone can lower blood pressure and make you dizzy and drowsy. Do not drive or operate machinery until you know how this medicine affects you. Arise slowly from a sitting or lying position to avoid falls.

Avoid drinking alcohol while on chlorthalidone, as this can worsen the side effects.

If you are also taking cholesterol-lowering medications like colestipol or cholestyramine, take them at least 1 hour after you take chlorthalidone.

Chlorthalidone can increase sensitivity to sunlight. Use proper sun protection and wear protective clothing while on this drug.

Chlorthalidone Drug Interactions

Taking chlorthalidone with certain other drugs can affect how it works. Possible drug interactions between chlorthalidone and other medicines can also increase the risk of severe adverse effects. The following medications can have possible drug interactions with chlorthalidone: 

  • Other medicines used to treat high blood pressure (hypertension)
  • Steroid medicine like prednisone
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Motrin, Advil) and naproxen (Naprosyn, Aleve)
  • Diabetes medication
  • Lithium (Lithobid, Eskalith)
  • Probenecid (Benemid)

The above list may not describe all possible interactions of chlorthalidone. Give your doctor or pharmacist a complete list of your medications, including prescription drugs, over-the-counter medications, dietary supplements, and herbal remedies. Also, tell your health care professional if you smoke, drink alcohol, or use recreational drugs because some of these substances can cause serious health complications when used with prescription medicines.