QT-Prolonging Meds Commonly Doled Out to Dialysis Patients

Non-nephrologists frequently prescribed QT-prolonging medications with known torsades de pointes (TdP) risk to older dialysis-dependent patients, and often these prescriptions came from nonacute settings, a cross-sectional study suggested.

Among Medicare patients with kidney failure receiving in-center hemodialysis, 52.9% filled an outpatient prescription for one of the seven most frequently filled QT-prolonging medications with known TdP risk, Jennifer Flythe, MD, MPH, of the University of North Carolina Kidney Center in Chapel Hill, and colleagues reported.

The majority (78.6% to 93.9%) of QT-prolonging medication prescriptions with known TdP risk occurred outside of an acute care event, and less than 25% occurred within 1 week of an acute care encounter, they wrote in JAMA Network Open. Most prescriptions (80.2%) originated from non-nephrologists.

"We were surprised that so many of the potentially risky medications were prescribed in the outpatient setting by non-nephrology clinicians," Flythe told MedPage Today. "This finding helps us know where and to whom to target interventions."

These patients already had higher risks for drug-related harms due to altered drug metabolism than the general population and typically had numerous comorbid conditions managed by multiple clinicians and prescription medications, Flythe pointed out. QT-prolonging medications with known TdP risk have been linked with higher risk of sudden cardiac death, which is a leading cause of mortality in hemodialysis patients.

Clinicians should perform medication reconciliation on a regular basis and look closely for pairs of potentially interacting medications, co-author Virginia Wang, PhD, of Duke University School of Medicine in Durham, North Carolina, suggested.

"At the health system [level], there are many opportunities to better coordinate care and prevent risky medication prescriptions," Wang told MedPage Today. "These include focused clinician education about high-risk medications, dedicated resources for medication reconciliation, and improving medication monitoring systems at dispensing pharmacies and prescription drug plans."

"All potential solutions require better information exchange and underscore the importance of improving clinician-to-clinician communication and increasing the interoperability of electronic health data systems," she said.

The analysis included 20,761 Medicare Parts A, B, and D beneficiaries receiving in-center hemodialysis in 2019. About 51% were male and the average age was 74. Most patients prescribed medications with a known TdP risk were prescribed antibacterials or antifungals: azithromycin (30.7%), ondansetron (30.6%), levofloxacin (21.4%), ciprofloxacin (19.3%), amiodarone (14.7%), escitalopram (9.0%), and fluconazole (7.9%).

Compared with nonusers, patients prescribed a QT-prolonging medication with known TdP risk were more often female (52.6% vs 44.7%) and white (56.0% vs 47.9%). They also had higher rates of heart failure (53.1% vs 44.2%), arrhythmias (42.4% vs 33.2%), depression (26.8% vs 16.1%), polypharmacy (65.0% vs 49.6%), and hyperpharmacy (17.7% vs 8.8%).

Less than 20% of these prescriptions originated from nephrologists; many came from general medicine clinicians (36.8% to 61%). Advanced practice clinicians wrote 13.6% to 19.6% of new prescriptions.

Up to 26.2% of QT-prolonging medication prescriptions with known TdP risk occurred with concomitant use of another pharmacodynamically interacting QT-prolonging medication.

The findings were likely a "microcosm of a larger issue of risky prescription practices among individuals receiving maintenance hemodialysis," the researchers noted. Future studies should look into prescribing patterns of other potentially harmful medications like opioids, benzodiazepines, sedative hypnotics, and muscle relaxants, they added.

The study included data on prescription fills only, not medication use, the researchers acknowledged. In addition, the analysis was descriptive and did not quantify associations of prescription fills with adverse outcomes.

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