Generic Name: HYDROCHLOROTHIAZIDE
Brand Name: Hydrochlorothiazide
- Substance Name(s):
Use with caution in severe renal disease.
In patients with renal disease, thiazides may precipitate azotemia.
Cumulative effects of the drug may develop in patients with impaired renal function.
Thiazides should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma.
Thiazides may add to or potentiate the action of other antihypertensive drugs.
Sensitivity reactions may occur in patients with or without a history of allergy or bronchial asthma.
The possibility of exacerbation or activation of systemic lupus erythematosus has been reported.
Lithium generally should not be given with diuretics (see PRECAUTIONS, Drug Interactions ).
Acute Myopia and Secondary Angle-Closure Glaucoma Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma.
Symptoms include acute onset of decreased visual acuity or ocular pain and typically occur within hours to weeks of drug initiation.
Untreated acute angle-closure glaucoma can lead to permanent vision loss.
The primary treatment is to discontinue hydrochlorothiazide as rapidly as possible.
Prompt medical or surgical treatments may need to be considered if the intraocular pressure remains uncontrolled.
Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy.
Drug Interactions When given concurrently the following drugs may interact with thiazide diuretics.
Alcohol, Barbiturates, or Narcotics Potentiation of orthostatic hypotension may occur.
Antidiabetic Drugs (Oral Agents and Insulin) Dosage adjustment of the antidiabetic drug may be required.
Other Antihypertensive Drugs Additive effect or potentiation.
Cholestyramine and Colestipol Resins Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins.
Single doses of either cholestyramine or colestipol resins bind the hydrochlorothiazide and reduce its absorption from the gastrointestinal tract by up to 85% and 43%, respectively.
Corticosteroids, ACTH Intensified electrolyte depletion, particularly hypokalemia.
Pressor Amines (e.g., Norepinephrine) Possible decreased response to pressor amines but not sufficient to preclude their use.
Skeletal Muscle Relaxants, Nondepolarizing (e.g., Tubocurarine) Possible increased responsiveness to the muscle relaxant.
Lithium Generally should not be given with diuretics.
Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity.
Refer to the package insert for lithium preparations before use of such preparations with hydrochlorothiazide.
Non-Steroidal Anti-Inflammatory Drugs In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics.
Therefore, when hydrochlorothiazide and non-steroidal anti-inflammatory agents are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained.
The most common signs and symptoms observed are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis.
If digitalis has also been administered, hypokalemia may accentuate cardiac arrhythmias.
In the event of overdosage, symptomatic and supportive measures should be employed.
Emesis should be induced or gastric lavage performed.
Correct dehydration, electrolyte imbalance, hepatic coma and hypotension by established procedures.
If required, give oxygen or artificial respiration for respiratory impairment.
The degree to which hydrochlorothiazide is removed by hemodialysis has not been established.
The oral LD 50 of hydrochlorothiazide is greater than 10 g/kg in the mouse and rat.
Hydrochlorothiazide is a diuretic and antihypertensive.
It is the 3,4-dihydro derivative of chlorothiazide.
It is chemically designated as 6-chloro-3,4-dihydro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide and it has the following structural formula: Hydrochlorothiazide USP is a white, or practically white, crystalline powder which is slightly soluble in water, but freely soluble in sodium hydroxide solution.
Each tablet for oral administration contains 25 mg or 50 mg hydrochlorothiazide USP.
In addition, each tablet contains the following inactive ingredients: dibasic calcium phosphate, lactose monohydrate, pregelatinized starch, FD&C yellow No.6 lake, corn starch, colloidal silicon dioxide, and magnesium stearate.
Hydrochlorothiazide Tablets USP, 25 mg are light pink colored, round shaped, flat faced beveled edge uncoated tablets, debossed with ‘D’ and ‘27’ on one side separated by scoring and plain on the other side.
Bottles of 100 NDC 65862-133-01 Bottles of 1,000 NDC 65862-133-99 Hydrochlorothiazide Tablets USP, 50 mg are light pink colored, round shaped, flat faced beveled edge uncoated tablets, debossed with ‘D’ and ‘28’ on one side separated by scoring and plain on the other side.
Bottles of 100 NDC 65862-134-01 Bottles of 1,000 NDC 65862-134-99 PHARMACIST: Dispense in a well-closed container as defined in the USP.
Use child-resistant closure (as required).
Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].
Distributed by: Aurobindo Pharma USA, Inc.
279 Princeton-Hightstown Road East Windsor, NJ 08520 Manufactured by: Aurobindo Pharma Limited Hyderabad-500 038, India Revised: 04/2020
INDICATIONS AND USAGE
Hydrochlorothiazide tablets, USP are indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.
Hydrochlorothiazide tablets, USP have also been found useful in edema due to various forms of renal dysfunction such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure.
Hydrochlorothiazide tablets, USP are 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.
Pediatric Use There are no well-controlled clinical trials in pediatric patients.
Information on dosing in this age group is supported by evidence from empiric use in pediatric patients and published literature regarding the treatment of hypertension in such patients.
(See DOSAGE AND ADMINISTRATION, Infants and Children .)
Pregnancy Teratogenic Effects Pregnancy Category B Studies in which hydrochlorothiazide was orally administered to pregnant mice and rats during their respective periods of major organogenesis at doses up to 3000 and 1000 mg hydrochlorothiazide/kg, respectively, provided no evidence of harm to the fetus.
There are, however, no adequate and well-controlled studies in pregnant women.
Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
Nonteratogenic Effects Thiazides cross the placental barrier and appear in cord blood.
There is a risk of fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults.
Nursing Mothers Thiazides are excreted in breast milk.
Because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue hydrochlorothiazide, taking into account the importance of the drug to the mother.
INFORMATION FOR PATIENTS
Non-melanoma Skin Cancer: Instruct patients taking hydrochlorothiazide to protect skin from the sun and undergo regular skin cancer screening.
DOSAGE AND ADMINISTRATION
Therapy should be individualized according to patient response.
Use the smallest dosage necessary to achieve the required response.
Adults For Edema The usual adult dosage is 25 mg to 100 mg daily as a single or divided dose.
Many patients with edema respond to intermittent therapy, i.e., administration on alternate days or on 3 to 5 days each week.
With an intermittent schedule, excessive response and the resulting undesirable electrolyte imbalance are less likely to occur.
For Control of Hypertension The usual initial dose in adults is 25 mg daily given as a single dose.
The dose may be increased to 50 mg daily, given as a single or two divided doses.
Doses above 50 mg are often associated with marked reductions in serum potassium (see also PRECAUTIONS ).
Patients usually do not require doses in excess of 50 mg of hydrochlorothiazide daily when used concomitantly with other antihypertensive agents.
Infants and Children For Diuresis and for Control of Hypertension The usual pediatric dosage is 0.5 mg to 1 mg per pound (1 to 2 mg/kg) per day in single or two divided doses, not to exceed 37.5 mg per day in infants up to 2 years of age or 100 mg per day in children 2 to 12 years of age.
In infants less than 6 months of age, doses up to 1.5 mg per pound (3 mg/kg) per day in two divided doses may be required.
(See PRECAUTIONS, Pediatric Use .)