Comparison of Commonly Used Diuretics

THIAZIDE DIURETICS are among the drugs that significantly increase blood glucose. They can also increase cholesterol and triglycerides.¹ Other side effects include hypokalemia, metabolic alkalosis, hyponatremia, and hypomagnesemia.^1,6 Thiazides reduce renal calcium excretion, an effect that may be beneficial to people at risk of osteoporosis or kidney stones.¹

Chlorothiazide (oral)
(not available in Canada)

Diuril
250 mg/5 mL, suspension

Edema
0.5-1 g QD to BID

HTN
0.5-1 g QD to BID

≤2 hrs

6 to 12 hrs

500 mg: $2.91

N/A

Chlorothiazide (IV)
(not available in Canada)

Sodium Diuril
500 mg injection (IV)

Edema
0.5-1 g QD to BID

15 min

N/A

500 mg injection: ~$120

• Only thiazide available as an injectable.

Chlorthalidone

25, 50 mg tabs (U.S.);
50 mg tabs (Canada)

Edema
50 to 200 mg QD or every other day
(Canada: 50 mg QD)

HTN
25 to 100 mg QD
(Canada: 25 to 50 mg QD)

~2 hrs⁵

At least 24 hrs⁵

U.S.:
25 mg tab: ~$0.40

Canada:
50 mg tab: $0.15

• Diuretic with most evidence for improved CV outcomes (e.g., used in ALLHAT).¹ Has not been proven to provide better cardiovascular outcomes than hydrochlorothiazide.¹⁵ Comparative study ongoning.¹⁸
• May be more effective in lowering SBP (by ~5 mmHg) over a full 24-hour period than hydrochlorothiazide.¹⁶
• 12.5 mg chlorthalidone ~ hydrochlorothiazide 25 mg.¹
• In combination products, only available with atenolol, azilsartan, or clonidine (U.S.).

Hydrochlorothiazide

12.5, 25 mg, 50 mg tabs; 12.5 mg cap (U.S.)

Edema
25 to 100 mg QD or divided (Canada: 25 to 100 mg QD or BID)

HTN
12.5 to 50 mg QD, or 25 mg BID (Canada: 50 to 100 mg QD or divided)

2 hr

6 to 12 hrs⁵

U.S.:
25 mg tab: <$0.05

Canada:
25 mg tab: <$0.05

• Most commonly prescribed thiazide.
• Most widely available diuretic in combination products with other antihypertensives.¹

Indapamide
Lozide (Canada)

1.25, 2.5 mg tabs

Edema (U.S. only)
2.5 to 5 mg QD

HTN
1.25 to 2.5 mg QD

1 to 2 hrs⁶

At least

24 hrs⁶

U.S:
1.25 mg tab: ~$0.23

Canada:
1.25 mg tab: $0.08

• Reduced CV events (heart failure and death from stroke) in hypertensive patients ≥80 years vs placebo.²
• May be more effective in lowering SBP (by ~5 mmHg) over a full 24-hour period than hydrochlorothiazide.¹⁷
• In combo product with perindopril (Canada).
• 1.25 mg ~ hydrochlorothiazide 25 mg¹⁷

Metolazone
Zaroxolyn (Canada)

U.S.: 2.5, 5, 10 mg tabs

Canada: 2.5 mg tabs

Edema
5 to 20 mg QD

HTN
2.5 to 5 mg QD

≤1 hr

≥24 hr (dose-dependent)

U.S.:
2.5 mg tab: $1.5

Canada (brand):
2.5 mg tab: $0.24

• Absorption is slow and unpredictable.³
• More effective than other thiazides at CrCl <30 mL/min.³

LOOP DIURETICS are more potent diuretics than thiazides, but are less effective antihypertensives in most patients.¹ They are best reserved for edematous conditions (e.g., heart failure, renal failure).¹ Loops are recommended over thiazides for patients with GFR <30 mL/min/1.73 m².^1,7 A thiazide can be added to a loop to enhance diuresis.⁷ Like thiazides, loops can cause hypokalemia, metabolic alkalosis, and hypomagnesemia.^1,8 Loops are less likely to cause hyponatremia.⁸ Loops increase excretion of calcium, instead of reducing it like thiazides.¹ Loops can cause ototoxicity, usually with high IV doses in conjunction with other ototoxic medications.⁴  For edematous states, loops are usually dosed intermittently, as needed. For other tips on use, see our chart, Loop Diuretic Use in Heart Failure.

Bumetanide (oral)
Bumex (U.S.)
Burinex (Canada)

U.S.:  0.5, 1, 2 mg tabs
Canada: 1, 5 mg tabs

Edema: 0.5 to 2 mg QD. If needed, repeat every 4 to 5 hrs
(max 10 mg/day).

0.5 to 1 hr

4 to 6 hrs (dose-dependent)

U.S.:
1 mg tab: ~$0.50

Canada (brand):
1 mg tab: $0.85

• Well-absorbed⁹
• 0.5 to 1 mg oral bumetanide = 40 mg oral furosemide¹⁰
• Canadian labeling recommends a max dose of 5 mg in patients with hepatic failure.

Bumetanide (IV or IM)
(not available in Canada)

0.25 mg/mL injection

Edema
0.5 to 1 mg. If needed, repeat every 2 to 3 hrs (max 10 mg/day).

IV: minutes

IM:

40 min.⁵

3 to 6 hrs⁵

1 mg injection: ~$0.60

N/A

Ethacrynic acid (oral)
Edecrin

25 mg tab

Edema
50 mg QD to 50 to 100 mg BID

Take after a meal.

30 min

6 to 8 hr

U.S.:
25 mg tab: ~$8.50

Canada (brand):
25 mg tab: $1.07

• Useful in patients resistant to other diuretics (Canada).
• 50 mg oral ethacrynic acid ~ 40 mg oral furosemide¹¹
• More ototoxic than other loops.⁷
• Only loop without a sulfa group; may be useful for patients with allergic reaction to other loops or thiazides. See our chart, Sulfa Drugs and the Sulfa-Allergic Patient, for more information.

Ethacrynate sodium (IV)
Sodium Edecrin

50 mg injection

Edema
50 mg x 1

5 min

2 hrs⁵

U.S. $~2,500

Canada:

$135

• Not for IM or subcutaneous injection.
• More ototoxic than other loops.⁷
• Only loop without a sulfa group. May be useful for patients with allergic reaction to other loops or thiazides. See our chart, Sulfa Drugs and the Sulfa-Allergic Patient, for more information.

Furosemide (oral)
Lasix

20, 40, 80 mg tabs; 10 mg/mL oral solution;

Lasix Special*(Canada)

*see comments section

Edema
20 to 80 mg (Canada: 40 to 80 mg). May repeat, or increase by 20 to 40 mg, in 6 to 8 hrs. (max 600 mg/day; Canada: 200 mg/day). When effective dose reached, give QD or divide BID (morning and early afternoon; Canada: give QD or divide BID to TID)

HTN
40 mg BID (Canada: 20 to 40 mg BID)

<1 hr

6 to 8 hr

40 mg tab: <$0.10

40 mg tab: $0.04

• Loop with poorest oral absorption.⁹
• Lasix Special* is a high-dose oral formulation (500 mg tab) of furosemide, for hospitalized patients with GFR >5 to <20 mL/min/1.73 m² not responding to usual furosemide doses. Initial dose is guided by the IV dose found to be effective. Or, in patients who do not respond adequately to 80 to 160 mg of oral furosemide, the initial dose is 250 mg. After 4 to 6 hrs, if response is inadequate, dose may be increased to 500 mg. Max daily dose 1,000 mg.

Furosemide (IV or IM)

10 mg/mL injection

Edema
20 to 40 mg. May repeat, or increase by 20 mg, in 2 hrs. (Canada: max 100 mg/day). Once effective dose reached, give QD or divide BID. For pulmonary edema, dose is 40 mg, increased to 80 mg in 1 hr if needed (Canada: 40 mg, repeated in to 1.5 hrs if needed.)

IV: 5 min

IV: 2 hr

20 mg/2 mL vial: ~$2.15

Canada:
20 mg/2 mL amp: $1.87

• When switching to/from oral furosemide, keep in mind that oral furosemide bioavailability is ~50% (range 10% to 90%).^12,13

Torsemide (not available in Canada)
Demadex

5, 10, 20 mg tabs

Edema
10 to 20 mg QD (max 200 mg/day)⁵

HTN
5 to 10 mg QD⁵

1 hr⁵

12 to 16 hrs⁹

10 mg tab: ~$0.33

• Well-absorbed.⁹
• 10 to 20 mg oral torsemide = 40 mg oral furosemide¹⁰
• Doses >40 mg/day have not been studied in cirrhosis.⁵

POTASSIUM-SPARING DIURETICS are usually weak antihypertensives, but they can be added to a thiazide to treat hypokalemia.¹ They can increase the risk for hyperkalemia and should be used cautiously in patients with reduced kidney function and in those using an ACE inhibitor or ARB.⁴

Amiloride
Midamor

5 mg tab

5 to 20 mg QD

See comments for indications.

2 hr

~24 hrs

U.S.:

5 mg tab: $0.93

Canada (brand):

5 mg tab: $0.34

• Weak diuretic and BP lowering effect in most patients.
• Indications: adjunct to thiazide or loop diuretic in patients with heart failure or hypertension, to maintain potassium levels; edema associated with cirrhosis (Canada). Rarely used alone.

Eplerenone
Inspra

25, 50 mg tabs

HFrEF post-MI
25 to 50 mg (target dose) QD

HTN
50 mg QD or BID

Note: HFrEF indication requires dose reduction if potassium level ≥5.5 mEq/mL. Max dose 25 mg QD (HF) or BID (HTN) with moderate CYP3A4 inhibitors.

Not available

Not available

U.S.:

50 mg tab: ~$2

Canada (brand):

50 mg tab: $3.08

• Eplerenone is an aldosterone antagonist with less progesterone and androgen receptor antagonism than spironolactone.³
• Option for resistant hypertension.¹
• Benefit in HFrEF (morbidity and mortality reduction) due to RAS suppression.⁷
• Helps offset loop or thiazide diuretic-related potassium and magnesium losses.¹⁴
• Do not use if K >5.5 mEq/L (Canada: >5 mmol/L) at initiation, CrCl ≤30 mL/min (<50 mL/min for HTN), or with strong CYP3A4 inhibitors.

Spironolactone
Aldactone

25, 50 (U.S. only), 100 mg tabs

Edema
25 to 200 mg QD or divided

HTN
25 to 100 mg QD or divided (Canada: 200 mg max)

HF
25 to 50 mg QD

Hypokalemia (Canada)
25 to 100 mg/day

Primary hyperaldosteronism
See comments

Not available

2 to 3 days⁵

U.S.:

50 mg tab: ~$0.36

Canada:

25 mg tab: $0.09

• Option for resistant hypertension.¹
• Benefit in HFrEF (morbidity and mortality reduction) due to RAS suppression.⁷
• Helps offset loop or thiazide diuretic-related potassium and magnesium losses.¹⁴
• P-glycoprotein inhibitor.⁵
• Do not use in hyperkalemia or severe renal impairment.
• Primary hyperaldosteronism treatment:

100 to 400 mg/day pre-op (Canada: 75 to 400 mg/day), or lowest effective dose for maintenance.

• Primary hyperaldosteronism diagnosis (Canada)

400 mg/day x 4 days (short test), or 3 to 4 weeks (long test)

Triamterene
Dyrenium

50, 100 mg cap

(Only combo products available in Canada.)

Edema
100 mg BID
(max 300 mg/day)

Take after meals.

2 to 4 hr

7 to 9 hr

U.S. (brand):

50 mg cap: ~$9

• Can be used with other diuretics for added diuretic effect or to offset potassium loss.¹
• Can be used alone, but has weak antihypertensive effect.¹