Complex med regimens lead to nonadherence in heart failure patients

The U.S. population is aging. More people are being diagnosed with heart failure. The 5.7 million Americans currently with the condition is expected to jump to eight million by 2030.

A team from the University of Colorado (UC) in Boulder and Vanderbilt Heart and Vascular Institute in Tennessee published a study of the impact of polypharmacy in patients with heart failure in Clinical Interventions in Aging.

Previous work suggested heart failure patients take, on average, 6.8 prescription medications in addition to any OTC or alternative medications. Such complexity can produce significant

“Opportunities exist for pharmacists and other health care professionals to address polypharmacy and medication regimen complexity in patients with heart failure, which may include extended counseling for patients and caregivers, frequent patient follow-up, simplification of medication and clinic-based adherence assessments,” wrote lead author Michael Cobretti, with UC’s Department of Pharmaceutical Sciences, and colleagues.

The researchers compared medication complexity using the Medication Regimen Complexity Index (pMRCI), while also comparing those with ischemic cardiomyopathy (ISCM) to nonischemic cardiomyopathy (NISCM). The team divided 145 patients into “young-old” (60 to 74 years old) and “old-old” (75 to 89 years old) groups.

Nearly two-thirds were men (64.1 percent) with an average age of 73. The mean medication count was 13.3, with 28 percent taking 10 or less, 43 percent taking 11 to 15 and 29 percent taking 16 or more.

pMRCI scores did not differ significantly between young-old and old-old groups. Medication counts for were substantially higher for ISCM patients compared to NISCM (14.1±4.9 vs 12.2±4.5).

“Polypharmacy is a major risk factor for medication nonadherence, and 72 percent of the patients in our ambulatory cohort were taking eleven or more medications,” Cobretti et al. wrote. “From a public health perspective, this finding is of considerable importance, as the probability of an adverse drug reaction increases to 82 percent when seven or more medications are prescribed.”