Indapamide is a Thiazide-Like Diuretic

Indapamide is classified as a thiazide-like diuretic, specifically a non-thiazide sulfonamide diuretic. 1, 2

Classification and Chemical Structure

Indapamide belongs to a class called indolines, which are thiazide-like diuretics that differ chemically from traditional thiazides 2
Unlike traditional thiazides, indapamide does not possess the thiazide ring system and contains only one sulfonamide group 2
Its molecular structure includes both a polar sulfamoyl chlorobenzamide moiety and a lipid-soluble methylindoline moiety 2, 3

Indapamide has a longer duration of action (approximately 36 hours) compared to traditional thiazide diuretics 1, 2
It is rapidly and completely absorbed from the gastrointestinal tract, with peak blood concentrations reached in approximately 2 hours 2, 4
The terminal half-life of indapamide in whole blood is approximately 14-16 hours 2, 4
Indapamide is extensively metabolized by the liver with only about 7% of the dose excreted unchanged in urine 2, 4

Indapamide has a dual mechanism of action: diuretic effects and direct vascular effects 4, 5
At antihypertensive doses (2.5 mg daily), it produces limited diuresis while also decreasing peripheral vascular resistance 5
It acts in the cortical diluting segment of the distal tubules 4
Some evidence suggests it may have calcium channel blocking properties that contribute to its antihypertensive effect 3

Indapamide is used primarily for the treatment of hypertension 1, 2
It is also used in heart failure management for controlling sodium and water retention 1
In resistant hypertension, indapamide (particularly chlorthalidone or indapamide) is recommended as a replacement for other diuretics in step 2 of treatment 1
It has been shown to reduce stroke occurrence when combined with ACE inhibitors in patients with cerebrovascular disease 1

The usual daily dose ranges from 2.5-5 mg once daily 1, 2
Initial dosing typically starts at 2.5 mg 1
Indapamide maintains efficacy down to estimated glomerular filtration rates (eGFRs) of 30 mL/min/1.73m² 1

Chlorthalidone and indapamide (thiazide-like diuretics) are preferred over hydrochlorothiazide for hypertension management due to their longer duration of action 1
Indapamide may have fewer metabolic side effects compared to traditional thiazides 5
It has hypocalciuric effects that may be beneficial in patients with urinary stone disease 6

Like other diuretics, indapamide can cause electrolyte abnormalities, particularly hypokalemia 1
At daily doses of 2.5 mg and 5 mg, a mean decrease in serum potassium of 0.5 and 0.6 mEq/L respectively can occur 1
It may increase uric acid levels by about 1 mg/100 mL 1
Monitoring of electrolytes is recommended, particularly in patients at risk for electrolyte imbalances 1