Table 7

Evaluation of AHRQ's Pharmaceutical Outcomes Portfolio

Table 7: Level 1 Findings: QT Prolonging Medications

CERT	Population	Findings
Arizona	General population	Population based study found that despite information provided in the package insert, drugs with the potential for QT prolongation are prescribed and dispensed frequently in the outpatient setting.
Arizona	General population & Methadone patients	The Arizona CERT developed and continues to maintain an international registry of drug-induced arrhythmias at www.qtdrug.org. From that registry, the PI describes the most striking discovery in this project as being the detection of an unexpected drug toxicity and a new risk of toxicity from a group of intravenously administered drugs [methadone].
Arizona	Methadone patients	Contrary to recent reports in the literature, we concluded from our analysis of the cases that prolonged QT and TdP (Torsade de Pointes) can occur over a wide range of dosages including those recommended for addiction treatment.
Duke	Cardiac patients	Evaluation of the dofetilide risk management program initially found the program to be effective but also found a deficit in the knowledge of other QT-prolonging medications.
Duke	Cardiac patients	Additionally, Duke CERT studied dosage of dofetilide and sotalol, drugs to treat the same problem, but one (dofetilide) with a risk management program and one without. Found that dofetilide was used in more appropriate doses but was prescribed less often.
Vanderbilt	General population	Finalizing a list of drugs for which there is strong evidence that these agents cause both QT prolongation and TdP, and with sufficient frequency to be a factor in the clinical use of these drugs, and understand drug-drug interactions and sudden cardiac death.
Duke	General population	The use of QT prolonging medications in combination with either other QT prolonging medications or medications that inhibit the clearance of QT prolonging medications... Approximately 5% of patients who received a QT prolonging drug during the study period received one more additional QT prolonging medication and/or a medication with known potential for interaction with QT prolonging medication. Most of these potential drug interactions occurred in patients with one of more risk factors for TdP.

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Page last reviewed December 2007

Internet Citation: Table 7: Evaluation of AHRQ's Pharmaceutical Outcomes Portfolio. December 2007. Agency for Healthcare Research and Quality, Rockville, MD. http://archive.ahrq.gov/research/findings/final-reports/pharmportfolio/table7.html