chlorthalidone (Thalitone)

Hygroton, Thalitone (both discontinued in U.S.A.)

GENERIC AVAILABLE: Yes

Yes

Chlorthalidone is used in the treatment of high blood pressure, congestive heart failure, and edema (fluid retention).

Chlorthalidone generally is well tolerated.

Side effects include:

• dizziness,
• lightheadedness,
• headache,
• fatigue,
• nausea,
• vomiting,
• abdominal pain, and
• constipation.

More serious side effects include:

• Low blood levels of potassium, sodium, and magnesium due to increased excretion via urine.
• High blood calcium levels also can occur, especially in persons who are taking calcium supplements.
• Thiazide diuretics such as chlorthalidone increase the levels of uric acid in the blood, but gout (which is caused by high levels of uric acid) rarely occurs.
• Chlorthalidone can cause high blood sugars in patients with diabetes.

The optimal dose of chlorthalidone varies greatly from patient to patient.

For high blood pressure the recommended dose range is 25 to 100 mg daily. Most patients receive 12.5 to 25 mg daily.

Edema is treated with 50 to 100 mg daily or 100 mg every other day and the maximum dose is 200 mg daily.

Heart failure is treated with 12.5 to 100 mg daily.

Chlorthalidone can lower blood potassium and magnesium levels because both potassium and magnesium are lost in the urine. This is especially true in patients who are also taking another class of diuretics, called loop diuretics which includes furosemide (Lasix), bumetanide (Bumex), and torsemide (Demadex). Low potassium and magnesium levels can lead to abnormal heart rhythms, especially in patients taking digoxin (Lanoxin).

Chlorthalidone reduces the kidney's ability to eliminate lithium (Eskalith, Lithobid) in the urine. As a result, patients taking chlorthalidone at the same time as drugs containing lithium may develop high levels of lithium and lithium toxicity.

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin), naproxen (Naprosyn), and nabumetone (Relafen) can reduce the effectiveness of chlorthalidone though the reason for this is not clear. Blood sugar levels can be elevated by thiazide diuretics. Patients with diabetes may need to adjust the doses of of medications they are taking for treating diabetes.

Thiazide diuretics including chlorthalidone cross the placenta and can cause jaundice in the fetus or newborn. Therefore, chlorthalidone should not be used during pregnancy unless absolutely necessary.

Large doses of thiazide diuretics may suppress milk production, but the American Academy of Pediatrics considers thiazides to be compatible with breastfeeding.

What preparations of chlorthalidone are available?

Tablets: 15, 25, 50, and 100 mg.

How should I keep chlorthalidone stored?

Tablets should be stored at room temperature, 15 C - 30 C (59 F - 86 F).