Chlorothiazide is a diuretic and antihypertensive. It is 6-chloro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide.
Chlorothiazide is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.
Chlorothiazide has also been found useful in edema due to various forms of renal dysfunction such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure.
Chlorothiazide is indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effectiveness of other antihypertensive drugs in the more severe forms of hypertension.
Use in Pregnancy
Routine use of diuretics during normal pregnancy is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy and there is no satisfactory evidence that they are useful in the treatment of toxemia.
Edema during pregnancy may arise from pathologic causes or from the physiologic and mechanical consequences of pregnancy. Thiazides are indicated in pregnancy when edema is due to pathologic causes, just as they are in the absence of pregnancy (see PRECAUTIONS: Pregnancy). Dependent edema in pregnancy, resulting from restriction of venous return by the gravid uterus, is properly treated through elevation of the lower extremities and use of support stockings. Use of diuretics to lower intravascular volume in this instance is illogical and unnecessary. During normal pregnancy there is hypervolemia which is not harmful to the fetus or the mother in the absence of cardiovascular disease. However, it may be associated with edema, rarely generalized edema. If such edema causes discomfort, increased recumbency will often provide relief. Rarely this edema may cause extreme discomfort which is not relieved by rest. In these instances, a short course of diuretic therapy may provide relief and be appropriate.
Published Studies Related to Chlorothiazide
Effects of sodium restriction and hydrochlorothiazide on RAAS blockade efficacy
in diabetic nephropathy: a randomised clinical trial. 
blockade on residual albuminuria in patients with type 2 diabetic nephropathy... INTERPRETATION: We conclude that sodium restriction is an effective
Effect of valsartan, hydrochlorothiazide, and their combination on 24-h ambulatory blood pressure response in elderly patients with systolic hypertension: a ValVET substudy. [2011.08]
BACKGROUND: Stage 2 hypertension often requires combination antihypertensive therapy. Ambulatory blood pressure monitoring (ABPM) is a useful tool for studying antihypertensive drugs and their combinations. OBJECTIVE: This multicenter, double-blind, parallel-group, prompted-titration study of patients of at least 70 years of age with systolic hypertension compared the efficacy of valsartan, hydrochlorothiazide, and their combination on ambulatory blood pressure (ABP) reduction... CONCLUSION: In elderly hypertensives, starting combination therapy with valsartan/hydrochlorothiazide provides more effective 24-h blood pressure control than the monotherapy components, with few therapy-related side-effects.
A comparison of the efficacy and safety of irbesartan/hydrochlorothiazide combination therapy with irbesartan monotherapy in the treatment of moderate or severe hypertension in diabetic and obese hypertensive patients: a post-hoc analysis review. [2011.07]
Hypertension is difficult to treat in patients with type 2 diabetes mellitus (T2DM) or obesity. Combination therapies are often required to effectively lower blood pressure (BP) and attain BP goals... In patients with moderate or severe hypertension and with a BMI >/= 30 kg/m(2), initial treatment with irbesartan/HCTZ combination therapy was more effective than irbesartan monotherapy.
Moderate versus intensive treatment of hypertension using amlodipine/valsartan and with the addition of hydrochlorothiazide for patients uncontrolled on angiotensin receptor blocker monotherapy: results in racial/ethnic subgroups. [2011.07]
Combination therapy may reduce racial/ethnic differences in response to antihypertensives. In this post-hoc analysis, we evaluated treatment response by race/ethnicity among hypertensive adults enrolled in a 12-week, double-blind study in which patients previously uncontrolled (mean sitting systolic blood pressure [MSSBP] >/=150 and <200 mm Hg) on angiotensin receptor blocker (ARB) monotherapy (other than valsartan) for 28 days or more (n = 728) were randomized to amlodipine/valsartan 10/320 mg (intensive) or 5/160 mg (moderate)...
A titrate-to-goal study of switching patients uncontrolled on antihypertensive monotherapy to fixed-dose combinations of amlodipine and olmesartan medoxomil +/- hydrochlorothiazide. [2011.06]
In the prospective, open-label, titrate-to-goal Blood Pressure Control in All Subgroups With Hypertension (BP-CRUSH) study, 999 patients with hypertension uncontrolled on monotherapy (mean age, 55.6 +/- 11.4 years; baseline blood pressure [BP], 153.7 +/- 9.2/91.9 +/- 8.6 mm Hg) were switched to fixed-dose amlodipine/olmesartan medoxomil (AML/OM) 5/20 mg...
Clinical Trials Related to Chlorothiazide
Determining the Effect of Spironolactone on Electrolyte Supplementation in Preterm Infants With Chronic Lung Disease [Recruiting]
Bronchopulmonary dysplasia (BPD), also known as chronic lung disease (CLD), is a major
complication of premature birth and is associated with a significant increased risk of
complications including death. Diuretics have been used for decades in babies with BPD and
are considered a standard of care. Patients receive electrolyte supplementation to replace
the electrolytes removed by the diuretics. Spironolactone is not as good as other diuretics
at removing extra fluid, but it is different from chlorothiazide and furosemide because
instead of removing potassium, it actually can increase potassium levels in our body.
Spironolactone is used with chlorothiazide to try to minimize the potassium lost; therefore,
reduce the electrolyte supplementation needed. However, studies have suggested that preterm
babies aren´t developed enough to appropriately respond to spironolactone. Also, one study
has shown that adding spironolactone to chlorothiazide in patients with BPD has no effect on
whether or not patients receive electrolyte supplementation. This study will examine whether
there is a difference in the amount of electrolyte supplementation between patients
receiving chlorothiazide only or chlorothiazide plus spironolactone. the investigators
hypothesize there will be no difference in the amount of electrolyte supplementation between
the two groups.
Study of Genotype and Phenotype Expression in Congenital Nephrogenic Diabetes Insipidus [Completed]
I. Determine the relationship between genotype variations and clinical phenotype in
patients with congenital nephrogenic diabetes insipidus.
Treatment of Hypertension [Completed]
To determine whether the long-term treatment of essential hypertension without significant
target organ disease materially influenced mortality and/or cardiovascular renal morbidity.
Protocolized Diuretic Strategy in Cardiorenal Failure [Recruiting]
This research study is a randomized clinical trial to evaluate if taking diuretics
(medications that increase urine production and help with fluid removal from the body) in a
standardized fashion (using a guideline for adjusting doses based on measured urine output)
could improve health outcomes in patients with cardiorenal failure or cardiorenal syndrome
(combined heart and kidney failure) with edema (too much fluid in their arms, legs, and/or
lungs). Under usual care, these patients are treated with diuretics and other medications
in increasing doses, but not necessarily to maintain a specific amount of urine output per
day. Current heart failure (HF) treatment guidelines do not provide any standard protocol,
or guideline, for adjusting diuretic doses. At the point when kidney function worsens to
the degree that the kidneys are no longer able to respond to the medications used to remove
fluid, either ultrafiltration (UF) or dialysis (also called hemodialysis [HD]) is typically
started in order to remove fluid. In both UF and dialysis, excess fluid is removed from the
body by using a machine. In dialysis, both waste products and fluid are removed and
electrolyte abnormalities are corrected. In UF, only fluid is removed. Both procedures use
the same machine. This study will test whether a Protocolized Diuretic Strategy (ProDiuS),
a plan for adjusting diuretic doses based on measured urine output, will improve clinical
care for cardiorenal syndrome. Such a plan for adjusting diuretic doses is needed to
improve symptoms, decrease the length of hospital stays and rehospitalization rates, and
improve health-related quality of life (HRQOL) in cardiorenal syndrome patients.
Renin-Guided Therapeutics in the Management of Untreated, Uncontrolled, or Complicated Hypertension [Completed]
Plasma renin values determine whether volume or vasoconstrictor (renin) factors predominate
in elevating blood pressure and are useful in selecting effective antihypertensive
The researchers hypothesize that:
1. Plasma renin-guided therapeutics will improve systolic and diastolic blood pressure
control in patients with untreated hypertension as well as in patients with treatment
refractory or resistant hypertension that are managed by Clinical Hypertension
2. Renin-guided therapeutics will reduce the number of medications required to maintain
blood pressure control to <140/90 mmHg in hypertensive patients receiving 3 or more
medications, while under the care of a Clinical Hypertension Specialist.
3. Renin-guided therapeutics selection will reduce the total cost of antihypertensive care
provided by Clinical Hypertension Specialists.
Page last updated: 2015-08-10