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chlorothiazide (klor-oh-thye-a-zide)



Therapeutic: antihypertensives, diuretics

Pharmacologic: thiazide diuretics


Management of mild-to-moderate hypertension. Treatment of edema associated with Congestive heart failure, Renal dysfunction, Cirrhosis, Corticosteroid therapy, Estrogen therapy.


Increases excretion of sodium and water by inhibiting sodium reabsorption in the distal tubule. Promotes excretion of sodium, chloride, potassium, magnesium, phosphate, water, and bicarbonate. May produce arteriolar dilation. Therapeutic Effects: Lowering of blood pressure in hypertensive patients and diuresis with mobilization of edema.

Adverse Reactions/Side Effects

CNS: dizziness, drowsiness, lethargy, weakness. CV: hypotension. GI: anorexia, cramping, hepatitis, nausea, vomiting, pancreatitis. Derm: photosensitivity, rashes. Endo: hyperglycemia. F and E: hypokalemia, dehydration, hypercalcemia, hypochloremic alkalosis, hypomagnesemia, hyponatremia, hypophosphatemia, hypovolemia. Hemat: rarely blood dyscrasias, thrombocytopenia. Metab: hyperuricemia, hypercholes-terolemia. MS: muscle cramps. Misc: blurred vision.


Examination and Evaluation

  • Assess blood pressure periodically and compare to normal values (See Appendix F) to help document antihypertensive effects. Report low blood pressure (hypotension), especially if patient experiences dizziness or syncope.

  • Monitor signs of fluid, electrolyte, or acid-base imbalances, including lethargy, drowsiness, blurred vision, confusion, hypotension, and muscle cramps and weakness. Report excessive of prolonged symptoms to the physician.

  • Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

  • When used to treat edema, help determine drug effects by assessing peripheral edema using girth measurements, volume displacement, and measurement of pitting edema (See Appendix N). Also monitor signs of pulmonary edema such as dyspnea and rales/crackles (See Appendix K). Document whether peripheral and pulmonary symptoms are controlled adequately by diuretic therapy.

  • Be alert for signs of hyperglycemia, including confusion, drowsiness, flushed/dry skin, fruit-like breath odor, rapid/deep breathing, polyuria, loss of appetite, and unusual thirst. Patients with diabetes mellitus should check blood glucose levels frequently.

  • Monitor and report signs of thrombocytopenia (bruising, nose bleeds, bleeding gums), or unusual weakness and fatigue that might be due to anemia or other blood dyscrasias.


  • Implement fall-prevention strategies, especially in older adults of if patient exhibits sedation, dizziness, blurred vision, or other impairments that affect gait and balance (See Appendix E).

  • Use caution during aerobic exercise, especially in hot environments. Increased sweating will cause fluid and electrolyte loss, and may exaggerate diuretic side effects (dizziness, muscle cramps, and so forth).

  • To minimize orthostatic hypotension, patient should move slowly when assuming a more upright position.

  • Causes photosensitivity; use care if administering UV treatments. Advise patient to use sunscreens, protective clothing, and avoid prolonged sun exposure.

Patient/Client-Related Instruction

  • Remind patients to take medication ...

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