Medical Food and Meal Replacement Nutritional Supplements

In recent years, there has been a growing trend toward marketing enteral nutrition products as meal supplements or meal replacements.

Enteral nutrition products are defined as medical foods that are used to complement an individual’s nutritional needs.¹ In general, typically formulated as semisynthetic liquids and administered via a feeding tube, enteral nutrition products provide nutrition for patients who are unable to ingest food or liquids orally as a result of a medical condition, such as cancer or stroke, or for patients with impaired digestion.¹ Some enteral formulas provide supplemental nutrition, whereas others are used as the sole source of nutrition.^1,2 Enteral products are also commonly used as oral nutritional supplements, especially among aging patients who are affected by chronic diseases or who require adjunctive nutritional sources to meet their dietary needs.^1-3

Results from some clinical studies suggest that appropriate nutrition may improve a patient’s quality of life and clinical outcome, as well as decrease overall health care costs.^2,4 In recent years, enteral formulas have been marketed as meal replacement products for healthy individuals who are attempting to lose weight, have active lifestyles, or are seeking high-protein supplements.¹ Some health care providers may recommend these products for patients who^5,6:

• Require supplemental nutrition
• Frequently experience decreased appetite
• Have difficulty swallowing or chewing solid foods
• Have had surgery or an injury and require increased nutrition during the recovery process

For many individuals, enteral formulas are a convenient and healthy alternative to eating unhealthy foods or simply skipping a meal.¹ Enteral products recommended for self-care should contain pertinent nutritional information on the label, including calories, serving size, fat and protein content, and amounts of the other ingredients.¹ Pharmacists are in a pivotal position to ascertain the appropriateness of self-care use of these products and to guide patients in product selection. Many of these supplements are formulated in a flavored beverage form, but a few pudding formulations are available for patients with fluid-restricted diets or chewing or swallowing difficulties.

Nutritional Supplement Product Categories

Enteral products are generally classified into 3 categories: polymeric, oligomeric, and modular formulas (Online Table 1).^1,7,8

TABLE 1: CATEGORIES OF ENTERAL NUTRITION PRODUCTS

Category

Comments

Polymeric formulas

· Most frequently used enteral products

· Can generally be safely used for meal replacement or self-care when taken orally

· Designed for patients with normal digestive processes

· Contain macronutrients in the form of intact proteins, fatty acids, or oils plus carbohydrates

· Majority of individuals who need nutritional support tolerate and thrive with standard polymeric formulas

Oligomeric formulas

· Rarely consumed orally because of poor palatability

· Require medical supervision

· Sometimes known as predigested (requiring minimal digestion) or elemental supplements; contain hydrolyzed or partially hydrolyzed proteins in the form of free amino acids or peptides

· Carbohydrates are less complex

· Fat content is usually altered to enhance absorption in patients with impaired absorption

Modular formulas

· Formulated to supplement a single macronutrient, such as protein powder, medium-chain triglyceride oil, and powdered flavored glucose polymers

· Can be taken with other foods to increase the caloric and protein content consumed

Adapted from references 1, 7, 8.

In addition, some specialty formulas are designed to meet the nutritional needs of patients with specific medical conditions such as diabetes and renal, pulmonary, and immune disorders (Table 2).^1,3 These specialty formulas usually require medical supervision and consultation with a dietician, board-certified nutritionist, or board-certified nutrition support pharmacist.¹ Types of specialty formulas include^1,3 :

• Diabetic formulations for patients with glucose intolerance
• Pulmonary formulas for patients with carbon dioxide retention and pulmonary conditions
• Renal formulas designed to decrease the risk for fluid overload

The Pharmacist’s Role

As the use of enteral nutrition products for meal supplementation or replacement grows in popularity, pharmacists can be instrumental in ensuring that their patients select the appropriate products and use them correctly. They can also help to ensure that these patients are monitored routinely by their physicians when warranted.

Before using any enteral nutrition product, patients should be encouraged to discuss the use of these products with their primary health care provider. While drug—nutrient interactions between enteral products and medications are not fully understood, they do have the potential to occur, and pharmacists can play a key role in identifying them.^1,9,10 One key interaction involves patients on anticoagulant therapy. Some enteral nutrition products may contain high levels of vitamin K, which could interfere with anticoagulation.^1,9,10 In addition, general recommendations for certain pharmacologic agents, such as phenytoin, carbamazepine, and warfarin, are to withhold administration of the enteral product for at least 1 to 2 hours before and after administering medication, especially when therapeutic doses are not reached with typical doses.^1,9,10 Patients taking medications should be advised to discuss this issue with their primary health care provider.

It is important for pharmacists to inform patients that the use of meal replacement products as the sole source of nutrition for longer than 2 to 3 weeks should be done only under medical supervision.¹ The pharmacist can also offer tips for making these products more palatable, such as chilling the product and trying various flavors to find a flavor of preference. Patients should be reminded to refrigerate opened products promptly and discard any unused portion after 24 hours of opening to prevent microbial growth.¹

Medical supervision is recommended when enteral products are provided via tube feedings. Caregivers should be instructed regarding proper aseptic technique with regard to tube feeding administration. Guidelines and tips for proper tube feeding can be found at the Oley Foundation website (www.oley.org/ tubetalks.html) and the American Society of Parenteral and Enteral Nutrition website (www.nutritioncare.org/About_Clinical_ Nutrition/What_is_Enteral_Nutrition/).

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.

References

1. Rollins C. Functional and meal replacement foods. In: Krinsky D, Berardi R, Ferreri S, et al, eds. Handbook of Nonprescription Drugs. 17th ed. Washington, DC: American Pharmacists Association; 2012.

2. Delivering therapeutic nutrition to patients with acute and chronic conditions. Abbott Nutrition for Healthcare Professionals website. http://abbottnutrition.com/categories/therapeutic/therapeutic-nutrition-center. Accessed December 2, 2014.

3. Enteral tube nutrition. The Merck Manual Professional Edition website. www.merckmanuals.com/professional/nutritional_disorders/nutritional_support/enteral_tube_nutrition.html. Accessed December 2, 2014.

4. De la Torre AM, de Mateo Silleras B, Pérez-García A. Guidelines for nutrition support in the elderly. Public Health Nutr. 2001;4(6A):1379-1384.

5. Ensure product information. Abbott Laboratories website. http://ensure.ca/en/faq. Accessed December 2, 2014.

6. Experts on nutrition. Nestlé Health Science website. www.boost.com/experts-on-nutrition. Accessed December 2, 2014.

7. NCI dictionary of cancer terms: polymeric enteral nutrition formula. National Cancer Institute website. www.cancer.gov/dictionary?cdrid=658777. Accessed December 2, 2014.

8. Lochs H, Allison SP, Meier R, et al. Introductory to the ESPEN Guidelines on Enteral Nutrition: Terminology, definitions and general topics. Clin Nutr. 2006;25(2):180-186.

9. Williams NT. Medication administration through enteral feeding tubes. Am J Health-System Pharmacy. 2008;65(24):2347-2357.

10. Magnuson BL, Clifford TM, Hoskins LA, et al. Enteral nutrition and drug administration, interactions, and complications. Nutr Clin Pract. 2005;20:618-624.

11. Our products. Abbott Nutrition for Healthcare Professionals website. http://abbottnutrition.com/brands/abbott-brands. Accessed December 2, 2014.

12. Products. Nestlé Health Science website. www.nestlehealthscience.com/products/Pages/home.aspx. Accessed December 2, 2014.