Polypharmacy: A Look into Over Medicating

Abstract

Polypharmacy is the use of multiple medications simultaneously by an individual patient.  It is growing and becoming more popular in the United States, especially among the elderly.  There has been little research to determine safety and health risks in combining multiple medications.  Most medication errors are a serious safety concern and most errors are preventable.  There are different kinds of polypharmacy that are appropriate and others that are not.  Although polypharmacy is sometimes appropriate, it still remains an issue for elderly people and patients with complex needs.

Polypharmacy:  A Look Into Over Medicating

There are many definitions of polypharmacy.  Some definitions are broad, stating that it is the use of potentially unnecessary and excessive amounts of medications; and some are narrower, stating that polypharmacy is prescribing more than one drug from the same class for the same patient at the same time (Klein). Even though polypharmacy may occur in all age groups, it is a common occurrence in elderly people.  While medication errors have received national attention, research about medication errors has not adequately addressed the factors associated with them or the factors that may prevent them.  Polypharmacy has been associated with increased mortality rates.  For example, it has been reported that each year 106,000 Americans die from properly prescribed and correctly taken medications (Picone).

The use of drugs is becoming more and more common.  Many people become more dependent on them and begin to abuse them; making polypharmacy more noticeable in today’s society.  Most people do not realize that using drugs, even prescriptions, have consequences that can be life long.  I chose this topic because the problem of polypharmacy is everywhere.  I expect to find that polypharmacy is not well known and little is being done about it. 

In the article by Hogan and Kwan (2006), they talk about how many drugs are used today for the prevention and treatment of diseases and other medical conditions.  They are either prescribed by healthcare practitioners or available over the counter without a prescription.  With each additional medication taken, people are at increased risk of adverse reactions from side effects and from interactions between drugs.  So, without knowledge, communication, and organization people become more susceptible to polypharmacy. 

Although polypharmacy may occur in all age groups, it is a common occurrence in elderly people.  In the article by Miller (2005), he studied data from the 1996 Medical Expenditure Panel Survey Nursing Home Component, which is a national survey of nursing home staff and residents.  The survey assessed nursing home use and expenditures for nursing home residents admitted during 1996.  Medication data was obtained from charts.  The information gathered from residents’ age 65 years and older revealed inappropriate medication prescribing, inappropriate drug choice, excessive dosage, and drug-disease interaction.  The final analysis included 3,372 residents.  During one year, one third was hospitalized and nearly one in five died.  Residents that are exposed to inappropriate medications are at greater risk for hospitalization and death. 

The American journal of Medical Quality (2008), states that medication errors are a serious safety concern and most errors are preventable.  Although medication errors have received national attention, research about medication errors has not adequately addressed the factors associated with them or the factors that may prevent them.

Sources of medication errors are errors in prescribing, transcribing, dispensing, or administering a medication (Picone).  Few healthcare providers have been educated in geriatric medicine and understand the uniqueness of prescribing medications for older adults.  The differences may be a greater or lesser medication effect or a unique effect that does not occur in a younger patient.  Elderly patients also my have a more varied and less predictable response.  Part of the problem comes from not understanding pharmacokinetics, which is knowing the time course and deposition of a drug in the body, based on its absorption, distribution, metabolism, and elimination.  Many of these problems arise from a lack of basic knowledge.     

Understanding the basics of Pharmacokinetics

Many factors influence the efficacy, safety, and success of drug therapy with older patients (Williams).  One factor is understanding pharmacokinetics.  It describes how the body absorbs a medication into the bloodstream, distributes it to the appropriate site of action, and how the medication is inactivated and excreted.  Age-related changes in the pharmacokinetic process put elderly patients at a risk for medication interactions when they take multiple medications.  Each phase of the process is subject to age-related effects that may alter the intent of the medications.  As a person grows older, muscle and lean body mass are lost and the ratio of fatty tissue to lean tissue changes, altering the volume of distribution of drugs.  Phases of pharmacokinetics include absorption, distribution, metabolism, and excretion. 

Gastrointestinal absorption of drugs is the process by which a medication enters the body and moves into the blood stream and lymphatic system before moving to its site of action (Sloan).  Age-related changes that affect absorption include increased gastric pH, decreased gastric emptying, and increased duodenal diverticula.  In general, medications with a narrow therapeutic range are most affected by age-related changes in absorption. 

Distribution occurs after a medication reaches the systemic circulation.  How a medication is distributed is determined mainly by body composition.  As an individuals age, their body composition is altered (decreased lean muscle mass, increased fat mass, and decreased total body water) (Williams).    Drug dosage recommendations may have to be modified based on the patients composition. 

The liver is the major organ responsible for medication metabolism.  Hepatic metabolism is variable and depends on age, genotype, lifestyle, hepatic blood flow, hepatic diseases and interactions with other medications (Williams).  Aging decreases the liver mass, alters hepatic blood flow, and reduces protein synthesis and enzymatic activity. 

Renal elimination is the primary route of excretion for most medications; however, age related renal system changes in elderly patients significantly affect this process.  Drug elimination is correlated with creatinine clearance, which declines by 50 percent between 25 and 85 years of age (Williams).  Metabolites medication produced in the liver may depend on the kidneys for excretion and therefore will accumulate due to reduced renal function.

There are many other reasons for polypharmacy.  Medication interactions are far more likely to occur in the elderly that in the younger population primarily because older adults take more medications.  With aging, the incidence of having at least one chronic disease or condition increases substantially.  Elderly patients tend to have medical conditions that require them to take multiple drugs.  With each additional medication taken, they are at increased risk of adverse reactions from side effects and from interactions between drugs (Hogan, Kwan).  With chronic conditions, a number of different medications may be used to treat the diseases, and all prescribed medications may be justified; however, there usually are several physicians treating one patient.  Patients can have multiple healthcare providers prescribing multiple medications for several conditions with little, if any, coordination of care or medications.  Healthcare providers also willingly write multiple prescriptions because that is what the provider thinks the patient wants.  Little attention may be given to non-prescriptive methods of treatment, and both the patient and the physician may not think the visit was “successful” unless a prescription was written.  More than 60 percent of all physician visits include a prescription for medication (Williams).  Some interactions develop from a combined effect of three or more medications in the regimen.  Although not all medication interaction result in adverse drug reactions (ADRs), the potential for ADRs further complicates medication therapy in elderly patients.  Two drugs taken together increase the risk of adverse events by only six percent; yet five drugs taken regularly by an elderly patient will increase the risk of adverse reactions by 50 percent (Young). 

Prescribing inappropriate medications occurs in various healthcare settings, and older patients are especially at risk of adverse effects from polypharmacy.  Studies have found a link between inappropriate medication prescriptions and subsequent major health events including falls, hospitalizations, and death.  Inappropriate drug choice was the most common error, but other errors included excessive medication dosage and drug-disease interactions (Miller).  Polypharmacy is particularly harmful when the patient receives numerous amounts of medications for extended periods and in high dosage.  Most polypharmacy problems can be preventable.  Iatrogenic means a problem that you caused that could have been preventable. To prevent an iatrogenic illness caused by over prescribing, it is important to consider any new signs and symptoms in an older patient to be a possible consequence of current drug therapy (Williams).  Medication reactions may be misdiagnosed as new disease processes.  The problem of misdiagnosis is compounded because many symptoms that are actually side effects of medical treatment may be dealt with by adding medications to a regimen rather than removing the offending drug. 

According to Klein in Behavioral Healthcare Tomorrow, there are five different types of polypharmacy.  There is same-class polypharmacy, multi-class polypharmacy, adjunctive polypharmacy, augmentation, and total polypharmacy.  Same-class polypharmacy is the use of more than medication from the same medication class.  Multi-class polypharmacy is the use of full therapeutic doses of more than one medication from different medication classes for the same symptom cluster.  Adjunctive polypharmacy is the use of one medication to treat the side effects or secondary symptoms of another medication from a different medication class.  Augmentation is the use of one medication at a lower-than- normal dose along with another medication from a different medication class.  Total polypharmacy is the total count of medications used in a patient (Klein).

Occurrence of polypharmacy

Werder and Preskorn state that polypharmacy typically occurs in five prescribing situations:

1. Attempting to treat multiple illnesses.
2. Attempting to control symptomatology.
3. Attempting to accelerate the onset of actions or augment the effects of a preceding drug.
4. Attempting to treat phasic illness, such as many affective, anxiety, seizure, and neurodegenerative disorders.
5. Attempting to prevent or treat adverse effects of other drugs.

Methods

My participants were randomly chosen at several of the local nursing homes, mental health evaluation clinics and hospitals.  A total of 500 subjects (284 women, 216 men) (mean age 65).  I had my study and survey questions reviewed by the university IRB.  I made sure all the patients and residents information is kept confidential based upon HIPPA guidelines.  My study was approved by the ETSU VA IRB.  The study did not include any invasive procedures and did not perceive any psychological manipulation analyzed was 65 and older.  Within the randomized sample the participants were put into subgroups based on their amount of time spent within these facilities.  The staff and residents were included in the survey questions.  Resident, facility characteristics, hospitalization and death data were obtained from the facility records.  Pharmaceutical interventions were entered into the database by generic name and American Hospital Formulary Service (AHFS).  If an intervention was used for more than 95% of hospitalizations, it was grouped into quartiles (1 = low use to 4 = high use) with low use as the reference category. When an intervention was used for at least 5% 220 of the hospitalizations, but less than 95%, it was divided into 4 groups where 0 = no use, 1 = lowest third of use, 2 = median third of use, and 3 = highest third of use.  Each of the 500 subjects was tested for its association with a medication error.  A total of 76 variables were not significantly correlated with the dependent variable and were eliminated.  Descriptive information (N = 10 187 Hospitalizations) the average number of unique medical interventions provided was 4.03 per hospitalization.  A total of 66% of the medication errors involved drugs within 5 AHFS classification codes: central nervous system agents (20.2%); electrolytes, caloric, and water balance (18.6%); anti-infective agents (17.6%); cardiovascular drugs (11.9%); and blood formation and coagulation (7.3%).  The most common medications involved in errors were furosemide (n = 42), potassium-chloride (n = 39), heparin (n = 38), IV fluids (n = 32), insulin (n = 28), morphine sulfate (n = 25, warfarin (n = 23, metoprolol (n = 21), and phenytoin (n = 20).  Most of these medications have been identified by the Institute for Safe Medication Practices and others as having a heightened risk for causing patient harm.  In the final analysis, 2 patient characteristics were significant: gender and ethnicity.  The odds of a medication error were less for male patients than female patients (odds ratio [OR] = 0.81), and less for all other races as compared with Caucasians (OR = 0.57). The results showed that the importance of understanding that medication can have a significantly negative impact on older patients. 

Discussion

During my studies I found that polypharmacy occurs more often in the elderly population.  I found that the issue of polypharmacy has not been truly and properly researched.  I also found out that there are preventable measures that may help the lives of people.  Properly assessing patient’s medications will have a big impact on their reactions to drugs.  People should know their medications they are taking.  They should know their names, why they are taking them, how they should be taking them, the most serious side effects, and what to do if a problem should arise.  Communicating with your doctor and pharmacist will help minimize risks.

Conclusion

Medication therapy in elderly patients is difficult to manage and always has the potential of being hazardous.  With the age-related changes that affect the pharmacokinetics of a medication, prescribing medications is further complicated.  Assessment of a medication’s efficacy is difficult.  The situation becomes more complicated when the patient is taking multiple medications. 

 References

Duxbury, Andrew S. (1996).  Geriatrics: unmasking ‘polypharmacy’ problems and adverse drug effects. Consultant.

Hogan, David B.  Kwan, Marilyn.  (2006). Patient sheet: tips for avoiding problems with polypharmacy. (Public Health).  CMAJ: Canadian Medical Association Journal.

Kingsbury, Steven J. Lotito, Megan Leahy. (2007). Psychiatric Polypharmacy: The Good, the Bad, the Ugly.  Psychiatric Times.

Klein, Charles. (2004). Managing polypharmacy: reviewing literature to identify best practices.  Behavioral Health Tomorrow.

Miller, Karl E. (2005). Inappropriate prescriptions associated with poor outcomes.  American Family Physician.

Picone, Debra Masten ( 2008).  Predictors of Medication Errors Among Elderly Hospitalized Patients.  American Journal of Medicine.

Sloan, Richard W. (1992). Principles of drug therapy in geriatric patients.  American Family Physician.

Williams, Cynthia M. (2002).  Using medications appropriately in older adults. American Family Physician.

Young, Melodie S. (2001).  Polypharmacy in the elderly. Dermatology Nursing.