Common Polypharmacy Pitfalls

Dr. Vande Griend is an assistant professorat the University of Colorado DenverSchool of Pharmacy, Aurora, Colorado.

As the term implies, polypharmacycan be defined asthe use of multiple medicationsfor the treatment of a patient'smedical conditions. In addition, theterm polypharmacy suggests that moremedication is being used than is clinicallyindicated.^1,2 The number of medicationstaken by a patient that constitutespolypharmacy has not beendefined.

Patients at highest risk include theelderly and those with multiple comorbidmedical conditions. These 2 patientpopulations often require multiple medicationsto treat multiple health-relatedconditions. Other risk factors includerecent hospitalization, being prescribedmedication from multiple physicians,and purchasing prescription medicationfrom multiple pharmacies.^1,3

The fact that a patient is on multiplemedications to treat multiple diseasestates is not independently problematic.Consider, for instance, a patient withtype 2 diabetes and existing coronaryheart disease who has received a recentcoronary stent for a myocardial infarction.It is not unreasonable or uncommonfor this patient to be on 6 to 9medications to reduce his or her longtermrisk for diabetes complicationsand secondary coronary events. In fact,strict adherence to national treatmentguidelines for this patient will result ina minimum of 6 concurrent prescriptiontherapies. Polypharmacy becomesproblematic when negative outcomesoccur. Polypharmacy has been shownto result in unnecessary and/or inappropriatemedication prescribing; toincrease the risk for drug interactionsand adverse drug reactions; to lead tomedication nonadherence; and is alsolikely to increase overall drug expenditures.²

The prescribing of inappropriatemedication often results in polypharmacy.For example, consider an 85-yearoldwoman prescribed amitriptyline 50mg at bedtime for insomnia. Commonside effects of this medication in elderlypatients include constipation, urinaryincontinence, dizziness, dry mouth, anddry eyes. To "treat" the side effectsof this medication, a prescriber mayinitiate docusate with senna for constipation,oxybutynin for urinary incontinence,and eye drops for dry eyes. Here,the prescribing of one therapy to treatinsomnia results in a total of 5 medicationtherapies.

Treatment of Polypharmacy

Employing a structured framework maybe useful in helping pharmacists reduceinappropriate or unnecessary prescribing,adverse events, drug interactions,and nonadherence associated withpolypharmacy. The process includesthe following and can be used by allpharmacists, regardless of health caresetting:

• Obtain an accurate medicationand medical history. Identify allmedications the patient is taking,including any OTC therapies. Havinga complete list of medications candeter a provider from adding on anadditional therapy. Further, knowledgeof a specific medication beingused may explain a patient-specificsymptom or complaint. For example,knowing a patient is on an opioid analgesicmay explain why he or she hasconstipation. Obtaining a completehistory of the patient's medical conditionsalso is important. Identifying thepatient's medical history allows thepharmacist to identify inappropriatelyprescribed medications. For instance,knowing that a patient has end-stagekidney disease allows the pharmacistto know that the prescribed metforminis not appropriate for that particularpatient.
• Link each prescribed medicationto a disease state. Each medicationthe patient is prescribed shouldmatch a patient's diagnosis. Any medicationthat does not match a diagnosisis potentially unnecessary, and anattempt to discontinue the medicationshould be made.
• Identify medications that aretreating side effects. The use ofmultiple medications leads to a higherrisk of side effects. When side effectsoccur, additional medications can beinitiated to treat the side effect. Acommon example includes the use oflaxatives to treat the medication sideeffect of constipation. Other examplesare listed in the Table. Discontinuingone drug that is causing a side effectcan lead to the discontinuation ofseveral drugs.
• Initiate interventions to ensureadherence. Using combination products(eg, lisinopril/hydrochlorothiazidecombination pill) will reduceoverall pill number and potentiallyimprove adherence. Other strategiesinclude using generic options toreduce cost and using adherence aidssuch as pillboxes.²
• Reconcile medications upon anydischarge from hospital or skillednursing facility. A risk factor forpolypharmacy includes recent hospitalization.1,³ In addition, the transferof a patient from a hospital or skillednursing facility to his or her home hasbeen associated with adverse eventsand negative outcomes; a significantproportion of these events are relatedto changes made in the patient's drugtherapy during treatment in thesefacilities.^4,5 Evaluating a patient'smedication regimen and educating apatient upon discharge from a facilityis likely to reduce duplicate therapy,reduce inappropriate prescribing,and reduce unnecessary medication.Medication reconciliation has beenshown to result in a reduced risk ofdeath in patients discharged from askilled nursing facility.⁵
• Prevention. As the old adage goes,"an ounce of prevention is worth apound of cure." When recommendingor dispensing a medication, theappropriateness of the medication forthe patient and the potential for sideeffects must be considered. Any drugthat is unnecessary, inappropriate, orhas a high likelihood for causing sideeffects that would require additionaltherapy should not be recommendedor dispensed by a pharmacist.

Role of the Pharmacist

The role of the pharmacist in the preventionand treatment of polypharmacydiffers depending on the health caresetting. Long-term care pharmacistsroutinely evaluate drug therapy regimensin predominantly elderly patients.They adhere to federal regulations withthe goal of reducing negative outcomesassociated with polypharmacy. Hospitalpharmacists play a critical role in medicationreconciliation. Upon discharge,hospital pharmacists obtain a completeand accurate list of the patient's medications.They evaluate this list for drugtherapy problems that arise when medicationsare discontinued and initiatedduring hospitalization. Prior to patientdischarge, they intervene with the medicalteam to prevent or treat polypharmacy.Community pharmacists play a vitalrole in polypharmacy by preventing thedispensing of unnecessary, inappropriate,and side effect?prone medication.

In addition, any pharmacist in anysetting can obtain an accurate medicationand medical history, link each prescribedmedication to a disease state,identify medications that are treatingside effects, initiate interventions toimprove adherence, and reconcile medicationlists.

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

• 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.
• Hajjar ER, Cafiero AC, Hanlon JT. Polypharmacy in elderly patients. Am J Geriatr Pharmacother. 2007;5(4):345-351.
• Mackinnon NJ, Hepler CD. Preventable drug-related morbidity in older adults 1. Indicator development. J Manag Care Pharm. 2002;8(5):365-371.
• 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.
• 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.