23 July 2007
The use of diuretics is well established in the treatment of
hypertension. Thiazide diuretics are cheap and are the most widely used
antihypertensive agents. When used in patients with essential
hypertension and relatively normal renal function, thiazides are more
potent than the loop diuretics. However in patients with renal
insufficiency, thiazides are less effective and loop diuretics should
be used instead.
the elderly with no co-morbid conditions, diuretics are the drugs of
choice in the treatment of systolic diastolic hypertension and isolated
systolic hypertension. Diuretics not only reduce the incidence of fatal
and non-fatal strokes but also cardiovascular morbidity and mortality
and all-cause mortality. Several large clinical trials have also
demonstrated that even low dose thiazides effectively lower BP.
in combination with beta-blockers are effective in the treatment of
hypertension in the elderly. They can also be used in combination with
ACEIs for the treatment of heart failure. Low dose diuretics (e.g.,
hydrochlorothiazide < 25 mg) can potentiate the action of other
antihypertensive agents with minimal adverse metabolic effects even in
Diuretics should be avoided in patients with
gout as they can precipitate an acute attack. Potassium-sparing
diuretics may exacerbate hyperkalaemia due to ACEIs or ARBs and also in
patients with underlying renal insufficiency.
are uncommon, unless high doses are used. These include increased serum
cholesterol, glucose, uric acid and calcium levels; decreased
potassium, sodium and magnesium levels; and erectile dysfunction.
Potassium supplements may be required.
| Diuretic|| Starting Dose|| Recommended Maximum Dose|
| Chlorothiazide|| 250 mg|| 500 mg|
| Hydrochlorothiazide|| 12.5 mg|| 50 mg|
| Chlorthalidone|| 12.5 mg|| 50 mg|
5 mg/50 mg
| 1/2 tablet|| 1 tablet|
| Indapamide SR|| 1.5 mg|| 1.5 mg|
| Indapamide|| 2.5 mg|| 2.5 mg|
50 mg/25 mg
| 1 tablet|| 2 tablets|
Table12: Diuretics commonly used for the treatment of hypertension in Malaysia
Clinical Practice Guidelines on the Management of Hypertension