Health Information

Loop Diuretics

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These powerful diuretics are used to reduce fluid accumulation in the body.

Drugs in this family include bumetanide (Bumex), ethacrynic acid (Edecrin), furosemide (Lasix), and torsemide (Demadex) among others.

 

Potassium

Loop diuretics cause a constant and significant loss of potassium. The classic treatment for this is to eat bananas and drink orange juice. Potassium supplements are also frequently prescribed.

Magnesium

Long-term use (more than 6 months) of loop diuretics might lead to magnesium deficiency. 1,2,3 In turn, magnesium depletion can increase loss of potassium. 4

Since magnesium deficiency is common anyway, taking a magnesium supplement at standard U.S. Dietary Reference Intake (formerly known as the Recommended Dietary Allowance) levels might make sense.

Vitamin B1

Evidence suggests that loop diuretics interfere with the body’s metabolism of vitamin B 1 (thiamin). 5,9,10

This effect may cause adverse consequences in one group of individuals who commonly take loop diuretics: people with heart failure. The heart depends on B 1 for proper function; therefore, this finding suggests that taking a B 1 supplement may be advisable. In fact, preliminary evidence suggests that thiamin supplementation does indeed improve heart function in individuals with congestive heart failure (CHF). 6,7,11

Licorice

Licorice, too, affects potassium, and the combination of licorice and loop diuretics might cause unexpectedly rapid potassium loss. 8 However, the special form of licorice known as DGL (deglycyrrhizinated licorice) should not affect potassium levels.

Dong QuaiSt. John's Wort

Loop diuretics have been reported to cause increased sensitivity to the sun, amplifying the risk of sunburn or skin rash. Because St. John's wort and dong quai may also cause this problem, taking these herbal supplements during treatment with loop diuretics might add to this risk.

It may be a good idea to wear a sunscreen or protective clothing during sun exposure if you take one of these herbs while using a loop diuretic.

Revision Information

  • 1

    al-Ghamdi SM, Cameron EC, and Sutton RA. Magnesium deficiency: pathophysiologic and clinical overview. Am J Kidney Dis 24: 737–752, 1994.

  • 2

    Dorup I. Magnesium and potassium deficiency. Its diagnosis, occurrence and treatment in diuretic therapy and its consequences for growth, protein synthesis and growth factors. Acta Physiol Scand Suppl 618: 1–55, 1994.

  • 3

    Martin BJ and Millian K. Diuretic-associated hypomagnesemia in the elderly. ArchIntern Med 147: 1768–1771, 1987.

  • 4

    Whang R, Whang DD, and Ryan MP. Refractory potassium repletiona consequence of magnesium deficiency. Arch Intern Med 152: 40–45, 1992.

  • 5

    Brady JA, Rock CL, and Horneffer MR. Thiamin status, diuretic medications, and the management of congestive heart failure. J Am Diet Assoc 95: 541–544, 1995.

  • 6

    Seligmann H, Halkin H, Rauchfleisch S, et al. Thiamine deficiency in patients with congestive heart failure receiving long-term furosemide therapy: A pilot study. Am J Med 91: 151–155, 1991.

  • 7

    Shimon I, Almog S, Vered Z, et al. Improved left ventricular function after thiamine supplementation in patients with congestive heart failure receiving long-term furosemide therapy. Am J Med 98: 485–490, 1995.

  • 8

    Shintani S, Murase H, Tsukagoshi H, et al. Glycyrrhizin (licorice)-induced hypokalemic myopathy. Report of two cases and review of the literature. Eur Neurol 32: 44–51, 1992.

  • 9

    Hardig L, Daae C, Dellborg M, et al. Reduced thiamine phosphate, but not thiamine diphosphate, in erythrocytes in elderly patients with congestive heart failure treated with furosemide. J Intern Med. 2000;247:597-600.

  • 10

    Yue QY, Beermann B, Lindstrom B, et al. No difference in blood thiamine diphosphate levels between Swedish Caucasian patients with congestive heart failure treated with furosemide and patients without heart failure. J Intern Med. 1997;242:491-495.

  • 11

    Sole MJ, Jeejeebhoy KN. Conditioned nutritional requirements: therapeutic relevance to heart failure. Herz. 2002;27:174-178.