Complete Nurse's Guide to Diabetes Care, 3rd Edition

Chapter 25:


Barbara Kocurek, PharmD, BCPS, CDE, FAADE1

1Kocurek is the Director of Chronic Care Continuum for Baylor Scott and White Health in Dallas, TX.

There is no standard definition of polypharmacy. A commonly used definition is “the concomitant use of four or more medications.”

Many patients with diabetes will be on multiple medications and experience polypharmacy. Medications are considered the standard of medical care for diabetes and its related complications and it is not uncommon for patients to take five or more medications (Table 25.1).1–4 Since the use of multiple medications is likely unavoidable, the goal is to use the most appropriate medications to achieve control with minimal adverse effects, which would be appropriatepolypharmacy. Taking too many medications that cause harm, called inappropriate polypharmacy, is more common in patients with multiple prescribers, complex drug regimens, increased age, psychosocial factors, and adverse drug reactions that are interpreted as new medical conditions.5

Table 25.1—Drug Therapy for the Prevention and Management of Diabetes and Its Complications

Table 25.1—Drug Therapy for the Prevention and Management of Diabetes and Its Complications

Source: Adapted from the American Diabetes Association.3

Practical Point

The use of multiple medications (polypharmacy) is often required and beneficial in helping patients with diabetes achieve optimal blood glucose, blood pressure, and lipid control and manage other diabetes-related complications and comorbidities.


Polypharmacy can and often does result in patients experiencing adverse events, such as drug reactions, drug–drug interactions, drug–disease interactions, and decreased adherence to medications.5 The risk of an adverse drug event has been estimated to be 13% for two drugs, 58% for five drugs, and 82% for seven or more.1 The majority of adverse events among older adults involve patients using five or more concurrent medications, and two-thirds of adverse events are attributable to only four medication classes (either alone or in combination): warfarin (33%), insulins (14%), oral antiplatelet agents (13%), and oral hypoglycemic agents (13%).6

A report by the IMS Institute for Healthcare Informatics estimated that health-care costs caused by improper and unnecessary use of medications exceeded $200 billion in 2012, and these costs were attributed to 10 million hospital admissions, 78 million outpatient treatments, and 246 million prescriptions.7 The report examined avoidable costs in six “opportunity” areas, which included nonadherence, delayed evidence-based treatment practice, misuse of antibiotics, medication errors, suboptimal use of generics, and mismanaged polypharmacy. The avoidable cost opportunity from polypharmacy mismanagement among older adults was estimated to be $1.3 billion, with a range from $900 million to $1.7 billion.7 Most of these costs were incurred through emergency room visits and hospitalizations resulting from complications and adverse drug events.7


Many nondiabetes medications can directly affect blood glucose levels. Glucocorticoids, for example, commonly cause an increase in blood glucose levels. The following medications are known to raise blood glucose levels:8,9

• Glucocorticoids

• Niacin

• Thiazide diuretics

• HIV medications (e.g., protease inhibitors, nucleoside reverse transcriptase inhibitors)

• Atypical antipsychotics (e.g., clozapine, olanzapine, risperidone)

Conversely, some medications may cause a decrease blood glucose levels, including some antibiotics (e.g., quinolones), angiotensin-converting enzyme ACE inhibitors, and large doses of salicylates.

Patients should be counseled to monitor their blood glucose levels more frequently when starting or stopping medications that can affect blood glucose control. If the patient experiences hyperglycemia or hypoglycemia, they should notify their health-care provider.

Some commonly used prescription and over-the-counter medications can raise blood pressure or interfere with the effectiveness of blood pressure medications.10 These include the following:

• Glucocorticoids

• Nonsteroidal anti-inflammatory drugs, such as ibuprofen

• Nasal decongestants (e.g., naphazoline, ephedrine, oxymetazoline)

• Diet pills

• Cyclosporine

• Erythropoietin

• Tricyclic antidepressants

• Monoamine oxidase inhibitors

• Oral contraceptives

If these medications are used, the patient’s blood pressure should be monitored more frequently, and if a patient’s blood pressure increases, this should be communicated to the health-care provider.


Many factors contribute to medication nonadherence, and the number of medications that a patient takes is one of them. Adherence to medication is difficult to accurately measure, and currently, no generally accepted gold standard exists to measure adherence.11 Self-reporting often is used; however, it tends to be overestimated, making it difficult for the patient and health-care provider to effectively evaluate how medications are working and what changes may need to be made to the medication regimens. A 2007 systematic review on medication taking in patients with diabetes reported adherence rates to diabetes medications that varied from 31% to 87% in retrospective studies and from 53 to 98% in prospective studies.12

Practical Point

Common Factors Affecting Medication Adherence12,13

Regimen complexity

Dosing frequency more than twice a day

Remembering doses and refills


Adverse effects or fear of them

Lack of belief that the medication will help


As part of the assessment of medication-taking behaviors, it is important to address barriers patients may have to taking medications. Common barriers to taking medications include unacceptable side effects, lack of perceived effectiveness, and cost of the medications. Cultural barriers also should be assessed, as some cultures may have differing beliefs regarding the use of medications or have incorrect perceptions about taking medications. For example, some patients may not understand the chronic nature of diabetes and may see medication as a temporary measure, or they may discontinue medications once they have achieved glycemic or blood pressure goals. Patients may use cultural or folk remedies that could interact or cause side effects when combined with their prescription medications. Some patients may utilize nontraditional treatments and may resist adding prescription medications to their regimens.14

No one intervention improves medication adherence in all settings; however, interventions that improve patients’ understanding of their treatment regimens, provide counseling and accountability, offer strategies to assist patient self-monitoring, and increase access to affordable medications can improve medication adherence.15


A 2012 Cochrane Review evaluated the literature to determine which interventions improved appropriate polypharmacy and reduced medication-related problems in older adults.4 Interventions that were evaluated included pharmaceutical care and computerized decision support. The authors concluded that some evidence indicated that pharmaceutical care, provided by pharmacists in various settings, was beneficial in reducing inappropriate prescribing and medication-related problems. It was not clear, however, that this intervention always resulted in clinical improvements.

The 2015 American Geriatrics Society Beers Criteria provide guidelines to help manage polypharmacy and inappropriate medication use by improving prescription drug selection, evaluating drug use patterns, and educating clinicians and patients on proper drug use.16

Nurses can help ensure appropriate medication use by reviewing the patient’s medication list with the patient or caregiver at every visit. When possible, ask patients to bring in all the bottles of medicines they current are taking and assess the following:

• Completeness of the list: Does it include all prescription medications, over-the-counter drugs, herbal products, and vitamin and mineral supplements that the patient is taking? Does it match the prescriber’s medication list (medication reconciliation)?

• Medication adherence and possible barriers: Is the patient experiencing any problems with their medications? Do they have any concerns? Do they have any problems obtaining medications because of cost? This part of the assessment will be easier if open-ended questions are used, such as the following:

• During the past week, have you missed taking your medications?

• What makes it hard or gets in the way of you taking your medications?

• What do you do when you miss a dose?

If problems are noted during this review, they should be addressed at that visit or a follow-up visit scheduled.

Resources for Medication Information

• Pharmacists (many large hospitals and schools of pharmacy have drug information centers)

• Package inserts (usually found on the manufacturer’s website)

• Drugs@FDA (; a site providing therapeutic equivalents, approval history, labeling information, and consumer information)

• Drug Interaction Checker (available at

• Epocrates (, also available as an app)

If appropriate, review the patient’s medications to identify potential problems or opportunities to simplify the medication regimen.2,16

• Use the 2015 AGS Beers Criteria as a guide and identify medications in which the risks of use in older adults outweigh the benefits.16

• Determine whether the medications are prescribed by different providers. Are they filled at different pharmacies? If so, is communication clear among all providers and pharmacies?

• Could nonpharmacological or lifestyle changes be used to treat the medical condition?

• Are any medications duplicated (brand/generic or drugs from the same drug class)?

• Is there an indication for each medication?

• Is the medication having a positive therapeutic response?

• Is a generic version of the medication available?

• Is there a way to simplify the regimen (e.g., use a combination pill)?

• Is a medication being used to treat symptoms that are related to an adverse drug reaction?

Consider teaming up with a pharmacist who provides pharmaceutical care to have them assist with medication reviews. Communicate any potential drug-related problems to the patient’s health-care provider in a timely manner.


The following strategies may help patients with medication adherence:2

• Suggest pillboxes, calendars, watch alarms, or some other system that will help patients remember when to take their medications, if needed.

• Encourage patients to keep an up-to-date list of all their medications, including vitamins, over-the-counter medications, and herbal products. Patients often can obtain a list of their prescription medications from their pharmacy and develop a complete list from there.

• Prescribers should include the purpose for each medication and give specific directions for use—for example, “Take one tablet two times a day with breakfast and dinner for diabetes.”

• Encourage patients to use just one pharmacy to get their prescriptions, vitamins, and over-the-counter medications filled. This can help decrease the potential for drug–drug interactions, and the pharmacist is one of the best sources of information for over-the-counter medications.

• Encourage patients to discuss their medications and medication concerns with their health-care providers. Patients can use several medication-related websites and phone apps to obtain information and even help with medication-taking behaviors (e.g., some applications include MyMedSchedule, MyMeds, and RxRemindme).

For additional resources, see Dayer et al.17

Resources for Safe Medication Use

• Check Your Medicines: Tips for Taking Medicines Safely (

• Be An Active Member of Your Health Care Team (

• Medication Use Safety Training for Seniors (


The use of multiple medications (polypharmacy) is common in patients with diabetes. Medications can have both positive (e.g., improved glycemic control) and negative (e.g., emergency department visits and hospitalizations for adverse events) effects on patient outcomes. Nurses need to be aware of factors that can contribute to inappropriate polypharmacy and understand that steps can be taken to help ensure appropriate medication use. Nurses are in a key position to promote improved medication adherence by assessing for potential barriers and helping the patient to develop a plan to overcome these barriers.


1. Fulton MM, Allen ER. Polypharmacy in the elderly: a literature review. J Am Acad Nurse Pract 2005;17:123–131

2. Good CB. Polypharmacy in elderly patients with diabetes. Diabetes Spectrum 2002;15:240–248

3. American Diabetes Association. Standards of medical care in diabetes—2017. Diabetes Care 2017;40(Suppl. 1):S11–S24

4. Patterson SM, Hughes, C, Kerse N, et al. Interventions to improve the appropriate use of polypharmacy for older people (Review). 2012. The Cochrane Collaboration. Available from Accessed 26 May 2014

5. Austin RP. Polypharmacy as a risk factor in the treatment of type 2 diabetes. Diabetes Spectrum 2006;19:13–16

6. Budnitz DS, Lovegrove MC, Shehab N, et al. Emergency hospitalizations for adverse drug events in older Americans. N Engl J Med 2011;365:2002–2012

7. Avoidable Costs in U.S. Healthcare. The $200 billion opportunity from using medicines more responsibly. Report by the IMS Institute for Healthcare Informatics. Available from Accessed 26 May 2014

8. Pharmacist Letter Detail. Document, drugs that significantly increase blood glucose. Pharmacist’s Letter/Prescriber Letter, May 2014

9. American Diabetes Association, American Psychiatric Association, American Association of Clinical Endocrinologists, North American Association for the Study of Obesity. Consensus development conference on antipsychotic drugs and obesity and diabetes. Diabetes Care 2004;27:596–601

10. American Heart Association. Over the counter medications. Updated 4 April 2012. Available from Accessed 26 May 2014

11. Vik, SA, CJ Maxwell, DB Hogan. Measurement, correlates, and health outcomes of medication adherence among seniors. Ann Pharmacother 2004;38:303–312

12. Odegard PS, Capoccia K. Medication taking and diabetes: a systematic review of the literature. Diabetes Educ 2007;33:1014–1029

13. Grant RW, Devita NG, Singer DE, Meigs JB. Polypharmacy and medication adherence in patients with type 2 diabetes. Diabetes Care 2003;26:1408–1412

14. Tseng CW, Tierney EF, Gerzoff RB, Dudley RA, Waitzfelder B, et al. Race/ethnicity and economic differences in cost-related medication underuse among insured adults with diabetes: the Translating Research Into Action for Diabetes Study. Diabetes Care 2008;31:261–266

15. Zullig LL, Peterson ED, Bosworth HB. Ingredients of successful interventions to improve medication adherence. JAMA 2013;310:2611–2612

16. American Geriatrics Society. 2015 Updated Beers criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc 2015;63:2227–2246

17. Dayer L, Heldenbrand S, Anderson P, Gubbins PO et al. Smartphone medication adherence apps: potential benefits to patients and providers. J Am Pharm Assoc 2013;53:172–181