Understanding Consequences of Concurrent Therapies

Carl C. Peck, MD; Robert Temple, MD; Jerry M. Collins, PhD
JAMA. 1993;269(12):1550-1552. doi:10.1001/jama.1993.03500120088033.
Text Size: A A A
Published online

In 1989, the occurrence of a rare, life-threatening ventricular arrhythmia (torsades de pointes) in an otherwise healthy young woman led alert clinicians at the Naval Hospital in Bethesda, Md, to consider the possibility that the patient's near-fatal arrhythmia was triggered by a drug-drug interaction involving her antihistamine (terfenadine) and her antifungal (ketoconazole) medications.1 Consulting clinical pharmacologists from the Uniformed Services University of the Health Sciences and the US Food and Drug Administration (FDA) suggested that ketoconazole inhibited the oxidative metabolism of terfenadine. Analysis of blood samples revealed that the patient had high levels of unmetabolized terfenadine, a compound not usually detectable in blood because it is metabolized so quickly. Review of reports to the FDA's spontaneous reporting system revealed that among additional cases of torsades de pointes in patients receiving terfenadine, many were also receiving ketoconazole. This evidence led the FDA to ask Marion Merrill Dow, Kansas City, Mo,


Sign In to Access Full Content

Don't have Access?

Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more

Subscribe for full-text access to content from 1998 forward and a host of useful features

Activate your current subscription (AMA members and current subscribers)

Purchase Online Access to this article for 24 hours




Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).


Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

Related Content

Customize your page view by dragging & repositioning the boxes below.