Indications

• Edema linked with congestive heart failure, hepatic cirrhosis, various forms of renal impairment, and corticosteroid and estrogen therapy are all indications for hydrochlorothiazide.
• In the more severe type of hypertension, management of hypertension as a solitary therapeutic agent or to increase the efficiency of additional antihypertensive medicines
• Diabetic insipidus treatment
• Treatment of acidosis in the proximal tubules of the kidney
• Idiopathic hypercalciuria and calcium nephrolithiasis, osteoporosis, and exercise-induced hyperkalemia are all examples of idiopathic hypercalciuria.

Pharmacology

Thiazides, such as hydrochlorothiazide, cause the body to lose water (diuretics). They prevent Na+/Cl- reabsorption from the kidney's distal convoluted tubules. Thiazides also cause potassium loss and a rise in serum uric acid levels. Although thiazides are commonly used to treat hypertension, their hypotensive effects are not always related to diuretic activity. Although the mechanism is unknown, thiazides have been demonstrated to reduce hypertension-related morbidity and death. Thiazides promote vasodilation in vascular smooth muscles by activating calcium-activated potassium channels (large conductance) and blocking different carbonic anhydrases in vascular tissue.

Dosage (breakdown or, not) :

Adults:

• For Edema: The usual adult dosage is 25 to 100 mg daily as a single or divided dose.
• 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. In some patients (especially the elderly) an initial dose of 12.5 mg daily may be sufficient.

Child: 

• For diuresis and for control of hypertension: The usual pediatric dosage is 1 to 2 mg/kg/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 3 mg/kg/day in two divided doses may be required.

Interaction

Potentiation of orthostatic hypotension may occur when using alcohol, barbiturates, or narcotics.

Thiazides can compromise the regulation of diabetes mellitus by diet and antidiabetic drugs (oral medicines and insulin). Antihypertensive Medications: Potentiation or additive impact.

Contraindications

Patients with anuria and those who are hypersensitive to hydrochlorothiazide or other sulfonamide-derived medications should avoid taking it. In diabetic mellitus, therapy should not be started.

Side Effects

Hydrochlorothiazide is generally well tolerated. However, weakness, restlessness, dizziness, headache, fever, diarrhea, vomiting, sialadenitis, cramps, constipation, stomach irritation, nausea, anorexia, and hypotension are all possible adverse effects. Hyperglycemia, glycosuria, hyperuricemia, and muscular spasm may occur in rare cases.

Pregnancy:

Although there is evidence of fetal danger with hydrochlorothiazide medication, it is recommended if the benefits outweigh the risks. When edema is caused by a pathologic condition, thiazides should be used during pregnancy.

Precautions & Warnings

Thiazides should be used with caution in patients with severe renal disease, impaired hepatic function or progressive liver disease and gout.

Storage Conditions

Store between 15-30°C. Protect from light, moisture and freezing.