Common Polypharmacy Pitfalls

Author: Joseph P. Vande Griend, PharmD, BCPS


Dr. Vande Griend is an assistant professor at the University of Colorado Denver School of Pharmacy, Aurora, Colorado.


As the term implies, polypharmacy can be defined as the use of multiple medications for the treatment of a patient's medical conditions. In addition, the term polypharmacy suggests that more medication is being used than is clinically indicated.1,2 The number of medications taken by a patient that constitutes polypharmacy has not been defined.

Patients at highest risk include the elderly and those with multiple comorbid medical conditions. These 2 patient populations often require multiple medications to treat multiple health-related conditions. Other risk factors include recent hospitalization, being prescribed medication from multiple physicians, and purchasing prescription medication from multiple pharmacies.1,3

The fact that a patient is on multiple medications to treat multiple disease states is not independently problematic. Consider, for instance, a patient with type 2 diabetes and existing coronary heart disease who has received a recent coronary stent for a myocardial infarction. It is not unreasonable or uncommon for this patient to be on 6 to 9 medications to reduce his or her longterm risk for diabetes complications and secondary coronary events. In fact, strict adherence to national treatment guidelines for this patient will result in a minimum of 6 concurrent prescription therapies. Polypharmacy becomes problematic when negative outcomes occur. Polypharmacy has been shown to result in unnecessary and/or inappropriate medication prescribing; to increase the risk for drug interactions and adverse drug reactions; to lead to medication nonadherence; and is also likely to increase overall drug expenditures.2

The prescribing of inappropriate medication often results in polypharmacy. For example, consider an 85-yearold woman prescribed amitriptyline 50 mg at bedtime for insomnia. Common side effects of this medication in elderly patients include constipation, urinary incontinence, dizziness, dry mouth, and dry eyes. To "treat" the side effects of this medication, a prescriber may initiate docusate with senna for constipation, oxybutynin for urinary incontinence, and eye drops for dry eyes. Here, the prescribing of one therapy to treat insomnia results in a total of 5 medication therapies.

Treatment of Polypharmacy

Employing a structured framework may be useful in helping pharmacists reduce inappropriate or unnecessary prescribing, adverse events, drug interactions, and nonadherence associated with polypharmacy. The process includes the following and can be used by all pharmacists, regardless of health care setting:

  1. Obtain an accurate medication and medical history. Identify all medications the patient is taking, including any OTC therapies. Having a complete list of medications can deter a provider from adding on an additional therapy. Further, knowledge of a specific medication being used may explain a patient-specific symptom or complaint. For example, knowing a patient is on an opioid analgesic may explain why he or she has constipation. Obtaining a complete history of the patient's medical conditions also is important. Identifying the patient's medical history allows the pharmacist to identify inappropriately prescribed medications. For instance, knowing that a patient has end-stage kidney disease allows the pharmacist to know that the prescribed metformin is not appropriate for that particular patient.
  2. Link each prescribed medication to a disease state. Each medication the patient is prescribed should match a patient's diagnosis. Any medication that does not match a diagnosis is potentially unnecessary, and an attempt to discontinue the medication should be made.
  3. Identify medications that are treating side effects. The use of multiple medications leads to a higher risk of side effects. When side effects occur, additional medications can be initiated to treat the side effect. A common example includes the use of laxatives to treat the medication side effect of constipation. Other examples are listed in the Table. Discontinuing one drug that is causing a side effect can lead to the discontinuation of several drugs.
  4. Initiate interventions to ensure adherence. Using combination products (eg, lisinopril/hydrochlorothiazide combination pill) will reduce overall pill number and potentially improve adherence. Other strategies include using generic options to reduce cost and using adherence aids such as pillboxes.2
  5. Reconcile medications upon any discharge from hospital or skilled nursing facility. A risk factor for polypharmacy includes recent hospitalization. 1,3 In addition, the transfer of a patient from a hospital or skilled nursing facility to his or her home has been associated with adverse events and negative outcomes; a significant proportion of these events are related to changes made in the patient's drug therapy during treatment in these facilities.4,5 Evaluating a patient's medication regimen and educating a patient upon discharge from a facility is likely to reduce duplicate therapy, reduce inappropriate prescribing, and reduce unnecessary medication. Medication reconciliation has been shown to result in a reduced risk of death in patients discharged from a skilled nursing facility.5
  6. Prevention. As the old adage goes, "an ounce of prevention is worth a pound of cure." When recommending or dispensing a medication, the appropriateness of the medication for the patient and the potential for side effects must be considered. Any drug that is unnecessary, inappropriate, or has a high likelihood for causing side effects that would require additional therapy should not be recommended or dispensed by a pharmacist.

Role of the Pharmacist

The role of the pharmacist in the prevention and treatment of polypharmacy differs depending on the health care setting. Long-term care pharmacists routinely evaluate drug therapy regimens in predominantly elderly patients. They adhere to federal regulations with the goal of reducing negative outcomes associated with polypharmacy. Hospital pharmacists play a critical role in medication reconciliation. Upon discharge, hospital pharmacists obtain a complete and accurate list of the patient's medications. They evaluate this list for drug therapy problems that arise when medications are discontinued and initiated during hospitalization. Prior to patient discharge, they intervene with the medical team to prevent or treat polypharmacy. Community pharmacists play a vital role in polypharmacy by preventing the dispensing of unnecessary, inappropriate, and side effect?prone medication.

In addition, any pharmacist in any setting can obtain an accurate medication and medical history, link each prescribed medication to a disease state, identify medications that are treating side effects, initiate interventions to improve adherence, and reconcile medication lists.

Table
Selected Side Effects, Medication Cause, and Treatment That May Lead to Polypharmacy

Side Effect

Common Drugs Causing Side Effect

Common Drugs Treating Side Effect

Constipation

- Tricyclic antidepressants
- First-generation antihistamines
- Verapamil or diltiazem
- Opioid analgesics
- Calcium supplementation

- Psyllium
- Docusate/senna
- Lactulose

Insomnia

- Prednisone, pseudoephedrine
- Stimulants, antidepressants
- Theophylline

- First-generation antihistamines
- Benzodiazepines
- Zolpidem, zaleplon

Somnolence

- Antihistamines
- Benzodiazepines
- Gabapentin
- Opioid analgesics

- Stimulants
- Caffeine
- Modafinil

Cognitive impairment

- Oxybutynin/tolterodine
- Antihistamines
- Opioid analgesics
- Benzodiazepines

- Donepezil
- Rivastigmine
- Galantamine
- Memantine

Diarrhea

- Metformin
- Antidepressants
- Proton pump inhibitors
- Antibiotics

- Loperamide
- Diphenoxylate


References

  1. Zarowitz BJ, Stebelsky LA, Muma BK, Romain TM, Peterson EL. Reduction of high-risk polypharmacy drug combinations in patients in a managed care setting. Pharmacotherapy. 2005;25(11):1636-1645.
  2. Hajjar ER, Cafiero AC, Hanlon JT. Polypharmacy in elderly patients. Am J Geriatr Pharmacother. 2007;5(4):345-351.
  3. Mackinnon NJ, Hepler CD. Preventable drug-related morbidity in older adults 1. Indicator development. J Manag Care Pharm. 2002;8(5):365-371.
  4. Forster AJ, Murff HJ, Peterson JF, Gandhi TK, Bates DW. The incidence and severity of adverse events affecting patients after discharge from the hospital. Ann Intern Med. 2003;138(3):161-167.
  5. Delate T, Chester EA, Stubbings TW, Barnes CA. Clinical outcomes of a home-based medication reconciliation program after discharge from a skilled nursing facility. Pharmacotherapy. 2008;28(4):444-452.