HTN: Benefits and Risks/Harms of Implementation (2015)

HTN: Benefits and Risks/Harms of Implementation (2015)

Benefits and Risks/Harms of Implementing the Recommendations

Safety issues should be considered for each form of treatment recommended. Use clinical judgment when evaluating patients with co-morbid conditions. A description of the general benefits and risks associated with implementation of this guideline must be addressed. 

For more specific detail concerning the risks/harms, conditions of application and costs, see individual recommendations.

Factors to consider when exploring treatment options include:

  • If an individual is unable to meet the DRI for dietary potassium, calcium, and magnesium, there is an additional cost for supplements.
  • When evaluating nutrient intake, the RDN should consider all sources of:
    • Dietary potassium intake, including use of 'lite' salt and potassium-containing salt substitutes.
    • Dietary and supplemental calcium intake, including foods and beverages fortified with calcium and calcium from over-the-counter antacids containing calcium carbonate (e.g., Tums, Rolaids) (Office of Dietary Supplements)
    • Supplemental magnesium intake from over-the-counter antacids (e.g., Rolaids) and laxatives (e.g., Phillips' Milk of Magnesia) (Office of Dietary Supplements). 
  • Physician consultation is warranted prior to beginning any exercise program
  • If the physician recommends a graded exercise test with electrocardiogram (ECG), additional costs may be incurred.

Potential Benefits

A priority aim and benefit of implementing the recommendations in this guideline would be to improve the percentage of individuals who are able to meet their treatment goal of reducing blood pressure.

Risk/Harm Considerations

Potential risks/harms to consider when exploring treatment options include:

  • Supplementation of potassium or use of potassium-containing salt substitutes may be contraindicated in the following individuals with HTN:
    • Those with certain medical conditions, such as renal failure, diabetes mellitus with hyporeninemic hypoaldosteronism and obstructive uropathy, which impair renal excretion of potassium  
    • Those taking medications, such as angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, and potassium sparing diuretics, which increase the risk of hyperkalemia (Doorenbos and Vermeij, 2003; Perazella, 2000; Pal et al, 1995; Yap et al, 1976). 
  • In healthy people, excess calcium intake from food is rare; excess intake from calcium supplements are more likely. When taking calcium supplements, individuals should not exceed the tolerable upper intake level (UL) for calcium (≥2, 500mg for age 18-50 or 2, 000mg for ≥51 years). Exceeding the UL for calcium may be associated with excessively high levels of calcium in the blood (known as hypercalcemia) that may cause renal insufficiency, vascular and soft tissue calcification, hypercalciuria (high levels of calcium in the urine) and kidney stones, constipation, interference with the absorption of iron and zinc, increased risk of kidney stones, increased risk of prostate cancer and cardiovascular disease (Office of Dietary Supplements).
  • Caution use of magnesium supplements in excess of 350 mg, in persons with impaired renal function or kidney failure due to increased risk of magnesium toxicity (Office of Dietary Supplements)
  • When taking magnesium supplements, individuals should not exceed the UL for magnesium (350mg or more). In healthy people, excess magnesium from food does not pose a health risk. High doses of supplemental magnesium (particularly the following forms: magnesium carbonate, chloride, gluconate, and oxide) or medications containing magnesium can result in diarrhea, nausea and abdominal cramping (Office of Dietary Supplements).
  • When reducing sodium to control blood pressure, the RDN should apply clinical judgment for those with certain medical conditions (e.g., heart failure) and/or who are taking medications (e.g.,  thiazide diuretics), which can cause hyponatremia.

References:

Doorenbos, CJ, Vermeij, CG. Danger of salt substitutes that contain potassium in patients with renal failure. BMJ. 2003 Jan 4; 326 (7379): 35-36. 

Yap, V, Patel, A, Thomsen, J. Hyperkalemia with cardiac arrthythmia. Induction by salt substitutes, spironolactone, and azotemia. JAMA 1976 Dec 13; 236(24): 2, 775-2, 776.

Office of Dietary Supplements. Dietary Supplement Fact Sheet: Calcium. National Institutes of Health. Reviewed November 21, 2013. Accessed online June 04, 2015:
http://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/

Office of Dietary Supplements. Dietary Supplement Fact Sheet: Magnesium. National Institutes of Health. Reviewed November 4, 2013. Accessed online June 04, 2015:
https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/

Pal, B, Hutchinson, A, Bhattacharya, A, Ralston, A. Cardiac arrest due to severe hyperkalaemia in patient taking nabumetone and low salt diet. BMJ. 1995; 311: 1, 486-1, 487.


Perazella, MA. Drug-induced hyperkalemia: old culprits and new offenders. Am J Med. 2000; 109: 307-314. 

Standing Committee on the Scientific Evaluation of Dietary Reference Intakes and its Panel on Dietary Reference Intakes for Electrolytes and Water. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Food and Nutrition Board. Institute of Medicine of the National Academies.Washington, DC,  The National Academies Press; 2005. Accessed online: http://books.nap.edu/openbook.php?record_id=10925


Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Food and Nutrition Board. Food and Nutrition Board. Institute of Medicine. Washington, DC,  The National Academies Press; 1997. Accessed online June 04,  2015:
http://books.nap.edu/openbook.php?record_id=5776