Diuretics are a class of medications used to treat fluid build-up and swelling caused by certain conditions like cirrhosis, congestive heart failure and kidney problems. They may also be used alone or in combination with other medications to lower blood pressure. Thiazide and loop diuretics are two different kinds of diuretics that work through different mechanisms. Thiazides are the most widely used diuretics for hypertension and include chlorothiazide (Diuril), hydrochlorothiazide (HydroDiuril, Esidrix), indapamide (Lozol), metolazone (Zaroxolyn), chlorthalidone (Hygroton) and others. Furosemide (Lasix), torsemide (Demadex), ethacrynic acid (Edecrin) and bumetanide (Bumex) are all examples of loop diuretics.
Mechanism of Action:
Thiazide diuretics initially lower blood pressure by increasing sodium and water loss (as well as other electrolytes and nutrients) in the kidneys and decreasing the volume of blood required for the heart to circulate in the body, thereby reducing blood pressure. The initial mechanism of thiazides is short lived and the continued decrease in blood pressure is poorly understood, but thiazide diuretics are thought to work directly on the arteries to cause them to dilate and thereby reduce blood pressure.
Loop diuretics work in a different part of the kidneys by inhibiting the absorption of sodium, potassium, and chloride leading to electrolyte loss (sodium, potassium, chloride, magnesium, and calcium) and water loss, thereby decreasing blood pressure.
Although thiazide and loop diuretics work differently to reduce blood pressure and treat other conditions such as heart failure and fluid retention, they both lead to a loss of essential nutrients listed below.
| Vitamin/Nutrient | Mechanism of depletion | Suggested Action |
| Vitamin B1 | Thiamine, or Vitamin B1 deficiency has been evidenced in people using long-term diuretic therapy. | Supplement with a B vitamin complex as interrelationships create synergistic effect. Exercise increases requirements. |
| Folic Acid | Urinary excretion of folic acid may be increased. | Supplement 400-800 mcg daily. |
| Calcium | Loop diuretics increase urinary calcium excretion and may reduce serum calcium levels. | 500 – 750 mg of high quality calcium daily with magnesium and other minerals for a healthy bone matrix. Recommend to take no more than 500 mg at a time with food for maximal benefits. |
| Potassium | Loop and thiazide diuretics increase potassium loss from the urine. Potassium supplements may be necessary. | No specific dosage level has been established. Potassium citrate or malate can be obtained in the diet from fruits and vegetables. Safe supplement range can be 100 to 6000 mg daily. |
| Magnesium | Loop and thiazide diuretic action interferes with magnesium reabsorption in the kidney, leading to low blood levels of this important mineral. Low magnesium levels increase the risk of cardiac arrhythmias and impaired insulin signaling. | 250-300 mg magnesium daily with food or before bed. |
| Zinc | Thiazide diuretics increase urinary zinc excretion by 50-60% although serum zinc levels are often maintained through an unknown compensatory mechanism. Zinc depletion could be related to the associated impotence sometimes seen with thiazides. | 15 – 30 mg zinc daily with food. Zinc (especially zinc sulfate) can cause nausea if taken on an empty stomach. |
To avoid drug/nutrient depletions, we suggest the CPW B-50 complex once daily with food, and 1-2 tbsp. of our CPW Liquid Cal-Mag with zinc and potassium daily. Some people may choose to take additional zinc or potassium if needed.
Ask our pharmacist or our wellness specialists if:
You have concerns about mineral/vitamin deficiency.
You would like more information about choosing an appropriate supplement.
References:
- “Diuretics” High Blood Pressure (Hypertension. Mayo Foundation for Medical Education and Research. 2/2014 http://www.mayoclinic.org/diseases-conditions/high-blood-pressure/in-depth/diuretics/art-20048129 Accessed 6/10/2015
- Wittner, M, DiStefno, A, Wangemann P, Greger, R. “How Do Loop Diuretics Act? Drugs., 1991; 41 Suppl3:1-13 http://www.ncbi.nlm.nih.gov/pubmed/1712711 Accessed 6/10/2015
- Duarte, Julio D, and Rhonda M Cooper-DeHoff. “Mechanisms for Blood Pressure Lowering and Metabolic Effects of Thiazide and Thiazide-like Diuretics.” Expert review of cardiovascular therapy6 (2010): 793–802. PMC. Web. 18 June 2015.
- Junji Takaya, Hirohiko Higashino, Yohnosuke Kobayashi. Intracellular magnesium and insulin resistance. Magnesium Research. 2004; 17(2):126-136. Accessed 18 June 2015
- Stargrove M, Treasure J, McKee D. Herb, Nutrient and Drug Interactions. Mosby Elsevier Publishing, Missouri p. 222 – 224, 260, 274, 327-328, 351, 569-570, 615, 828.