Hydrochlorothiazide

Mechanism :

Hydrochlorothiazide is a thiazide diuretic. The mechanism of action of hydrochlorothiazide is an interference with the renal tubular mechanism of electrolyte reabsorption. Thiazides increase excretion of sodium and chloride in approximately equivalent amounts. Natriuresis causes a secondary loss of potassium and bicarbonate.

Indication :

• Hypertension
• Edema
• Nephrogenic diabetes insipidus
• Congestive cardiac failure
• Renal calculi

Contraindications :

Hydrochlorothiazide is contraindicated in anuria. It is also contraindicated in patients who have previously demonstrated hypersensitivity to Hydrochlorothiazide or other sulfonamide-derived drugs, severe renal and hepatic failure, Addison’s disease and hypercalcemia.

Dosing :

Adverse Effect :

Nausea and vomiting, cramping, anorexia, dizziness, paraesthesia, vertigo, xanthopsia, headache, leukopenia, thrombocytopenia, agranulocytosis, hemolytic or aplastic anemia, hypersensitivity reactions, purpura, urticaria, exfoliative ecchymosis, dermatitis, itching, necrotizing angiitis, (vasculitis, cutaneous vasculitis), respiratory distress, Stevens-Johnson syndrome, toxic epidermal necrolysis, orthostatic hypotension, weakness, muscle spasm, or restlessness; allergic glomerulonephritis, hyperuricemia, and transient blurred vision, glycosuria, hyperglycemia, ketoacidosis in diabetic patients.

Interaction :

Alcohol, Barbiturates, or Narcotics: Potentiation of ortho-static hypotension.
Anticoagulants: Bendroflumethiazide may decrease their effects.
Amphotericin B, Corticosteroids, or Corticotropin: Intensify electrolyte imbalance, particularly hypokalemia.
Antigout Medications: Bendroflumethiazide may raise the level of blood uric acid.
Antidiabetic Drugs: Elevate blood glucose levels, dosage adjustments of antidiabetic agents may be necessary.
Calcium Salts: Increased serum calcium levels due to decreased excretion.
Cardiac Glycosides: Enhanced possibility of digitalis toxicity.
Lithium Salts: May enhance lithium toxicity due to reduced renal clearance.
Nondepolarizing Muscle Advice: Effects of these agents may be potentiated; dosage adjustments may be required.
Nonsteroidal Anti-Inflammatory Agents: Can reduce the diuretic, natriuretic, and antihypertensive effect of loop, potassium-sparing or thiazide diuretics.
Pressor Amines: Decreased arterial responsiveness.
Probenecid or Sulfinpyrazone: Increased dosage of these agents may be necessary since bendroflumethiazide may have hyperuricemic effects.

Hepatic Dose :