Optimal Drug Use in Elderly Patients With CRC Requires Balance

Elderly patients with colorectal cancer tended to have poorer outcomes when they were taking five or more prescription medications, recent research showed.

Recent research found an association between polypharmacy — meaning that patients were taking five or more prescription drugs at a time — and death from any cause in older patients with colorectal cancer (CRC).

“Most older cancer patients have two or more comorbidities (other health conditions), and because of reasons such as underlying frailty, special attention is needed when prescribing drugs,” the researchers wrote in their article, which was published in the journal, Cancer.

The study, which was conducted in Korea, analyzed data from 55,228 patients aged 65 and older who received treatment for CRC and survived at least two years after being diagnosed. Patient data was split into three categories:

• Non-polypharmacy: patients who were prescribed zero to four prescribed drugs
• Polypharmacy: prescribed five to nine drugs
• Excessive polypharmacy: prescribed 10 or more drugs

Findings showed that 49.9% of patients in the non-polypharmacy group died of any cause, compared with 48.% in the polypharmacy group and 57.4% in the excessive polypharmacy group. Hospitalizations occurred in 82.1%, 85.9% and 88.8% and emergency room visits occurred in 44.1%, 51.6% and 60% in the non-polypharmacy, polypharmacy and excessive polypharmacy groups, respectively.

“(Polypharmacy) was associated with adverse outcomes, including all-cause mortality, hospitalization and ER visits among elderly CRC survivors,” the researchers wrote. “(Polypharmacy) was particularly associated with those who were aged 65 to 75 years and those with low risk of frailty.”

Patients who are not frail may be more likely to experience negative effects from polypharmacy because, according to the researchers, as people age and become frail, they may experience cognitive decline that results in decreased adherence to their medication regimens.

The researchers also noted that elderly patients are more likely than their younger counterparts to be exposed to polypharmacy, although taking five or more medications has been linked in prior research to falls, hospital readmissions, cognitive impairment, poor adherence to essential medications, chemotherapy side effects and increased mortality.

READ MORE: Taking 8-Plus Medications Before Cancer Treatment May Affect Effectiveness in Older Patients

There are a few potential reasons to why polypharmacy could be associated with increased mortality in the elderly, according to the researchers.

“Geriatric patientsare at risk of serious side effects because the physiological changes that occur as they age make their bodies more sensitive to the effects of drugs,” they explained. “Moreover, age‐related physiological changes also affect the pharmacokinetics (absorption, distribution, metabolism and excretion) and pharmacodynamics (studying the effects of drugs on the body) of drugs. These changes can affect the volume of distribution of many drugs, and if the dose is not adjusted, these changes can increase the risk of toxicity.”

The researchers also said that older patients may be more likely to experience prolonged side effects from their therapies, and taking multiple drugs in any given period increased the likelihood of harmful drug-drug interactions.

“These potential mechanisms are likely to affect elderly CRC survivors in a similar manner,” they wrote.

The dangers of polypharmacy for elderly patients with CRC could potentially be mitigated by education and open patient-provider communication, according to the study authors.

“These risks can be minimized by increasing awareness and enhancing behaviors among health care professionals, especially clinician and pharmacists should be aware of potential drug interactions, review and ongoing monitoring,” the authors wrote. “Therefore, to optimize drug use, it is necessary to find a balance between adequate treatment of diseases and avoiding adverse drug effects in survivors of CRC.”

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