Clinical studyPrescription of QT-prolonging drugs in a cohort of about 5 million outpatients☆
Section snippets
Study sample
We accessed the outpatient prescription claims database of AdvancePCS (Irving, Texas, and Scottsdale, Arizona), the largest pharmaceutical benefit manager in the United States. Health insurance carriers contract with Advance- PCS to manage their formularies and adjudicate their prescription drug claims. AdvancePCS maintains a computerized pharmacy system that records data on each prescription drug dispensed to its beneficiaries. More than 98% of the prescription drug claims are submitted and
Results
The mean (± SD) age of patients was 47.7 ± 16.3 years, and almost 60% were women (Table 1). The population was geographically diverse, with representation from all 50 states, the District of Columbia, Puerto Rico, and two U.S. territories. Of the 4.8 million patients, 1,097,871 (22.8%) filed claims for at least one QT-prolonging drug in 1999. Their mean age was 49.0 ± 16.0 years, and nearly two thirds were women (Table 1).
Nearly half (47.4%) of all patients with a claim for a QT-prolonging
Discussion
The findings of this population-based study suggest that drugs with the potential for QT prolongation, particularly antibiotics and antidepressants, are prescribed and dispensed frequently in the outpatient setting. Nearly 10% of patients who filled prescriptions for QT-prolonging drugs filled them in combination with another drug of concern; more than 25% of patients who filled a prescription for a QT-prolonging antidepressant filled an overlapping prescription for another drug of concern, as
Acknowledgements
The authors thank Damon Seils for editorial assistance and manuscript preparation, and O. Diana Bell for technical assistance.
References (33)
Proarrhythmia with class III antiarrhythmic drugstypes, risks, and management
Am J Cardiol
(1997)- et al.
Torsades de pointes and proarrhythmia
Lancet
(1993) - et al.
The QT interval
Prog Cardiovasc Dis
(2001) - et al.
Comparison of different methods to estimate prevalence of drug use by using pharmacy records
J Clin Epidemiol
(2001) - et al.
Risk of torsades de pointes with non-cardiac drugs. Doctors need to be aware that many drugs can cause QT prolongation
BMJ
(2000) - et al.
The potential for QT prolongation and pro-arrhythmia by non-anti-arrhythmic drugsclinical and regulatory implications. Report on a Policy Conference of the European Society of Cardiology
Cardiovasc Res
(2000) - et al.
Drug-induced torsades de pointes. Incidence, management and prevention
Drug Saf
(1994) - et al.
QT-interval prolongation by non-cardiac drugslessons to be learned from recent experience
Eur J Clin Pharmacol
(2000) A practical approach to torsades de pointes
Clin Cardiol
(1997)- et al.
Electrophysiologic mechanisms of the long QT interval syndromes and torsades de pointes
Ann Intern Med
(1995)
Drug Interaction Facts
Sotalol
N Engl J Med
Female gender as a risk factor for drug-induced cardiac arrhythmiasevaluation of clinical and experimental evidence
J Womens Health
Dofetilide, a new class III antiarrhythmic agent
Pharmacotherapy
The QT interval and torsades de pointes
Drug Saf
Cardiotoxic effect with convulsions in terfenadine overdose
BMJ
Cited by (0)
- ☆
This research was supported by Centers for Education and Research on Therapeutics (CERTs) cooperative agreement U18 HS10385, formerly between the Agency for Healthcare Research and Quality (AHRQ) and Georgetown University Medical Center, now between AHRQ and the University of Arizona Health Sciences Center. Drs. Curtis, Dans, Hutchison, Østbye, Schulman, Woosley, Wright, and Yasuda are supported in part by the CERTs program in Arizona. Drs. Allen LaPointe, Al-Khatib, and Califf are supported in part by the CERTs program at Duke University Medical Center.
- *
Dr. Sendersky is now with the Department of Health Economics and Outcomes Research, Novartis Pharmaceuticals Corporation, East Hanover, New Jersey.