IDSA News - April 2013  (Plain Text Version)

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In this issue:
Patient Care and Science
•  EIN Update: Antimicrobials, Heart Rhythm Effects, and Monitoring
•  Guideline-Related Tools Available from IDSA
•  CDC Issues H7N9 Health Advisory for Clinicians
Clinical Practice Management
•  Report Details ID Participation in CMS Incentive Programs
Global ID
•  High Court Hears Arguments in “Anti-Prostitution Pledge” Case
•  Report from Mozambique: Workshop to Scale Up HIV/TB Activities
•  Obama Budget Continues Support for Global Fund, Cuts PEPFAR Funds
Policy and Advocacy
•  President’s Budget Supports Some ID/HIV Priorities, Shortchanges Others
•  Thousands Rally to Support Medical Research in D.C.
•  More Data Needed on Antimicrobial Use in Animals
•  Redefined Scope, Additional Guidance Needed in DURC Oversight Policy for Institutions
Your Colleagues
•  Check Out “My IDSA” for Latest Member News
Education & Resources
•  Free IDSA Lyme Disease Online Course Offers CME Credit
•  Bright Minds Turn to the ID/HIV Career Center
Top Stories
•  From the President: Your Voice Can Make a Difference
•  IDSA Report: Antibiotic Pipeline Progress “Alarmingly Elusive”
•  “Ask the Coder” Your Tough Coding Questions
•  IDSA Journal Club

 

EIN Update: Antimicrobials, Heart Rhythm Effects, and Monitoring

The Emerging Infections Network (EIN) is a forum for infectious diseases consultants and public health officials to report information on clinical phenomena and epidemiological issues with public health significance. Any diagnostic or therapeutic recommendations and all opinions presented are those of the individual contributor. They do not necessarily represent the views of EIN, IDSA (EIN’s sponsor), or the Centers for Disease Control and Prevention (CDC), which funds EIN. The reader assumes all risks in using this information.

EIN members recently discussed antimicrobials affecting electrical activity of the heart, following a recent safety communication issued by the Food and Drug Administration on the use of azithromycin and clarithromycin.

“Fluoroquinolones and voriconazole are commonly used in my practice of ID oncology, and can cause QTc prolongation,” an EIN member in Florida wrote. “Is it a standard in your practice to check a baseline electrocardiogram (EKG), or follow-up EKG, when using these antimicrobials? Also, when other drugs that can prolong the QTc interval are being used concomitantly with the aforementioned antimicrobials, is it imperative to get a baseline EKG, or follow-up EKG?”

The member cited two related journal articles:

“This came up for me recently when I treated a woman with IgA nephropathy and M. fortuitum infection of the finger,” a respondent in Louisiana wrote. “Hoping to avoid trimethoprim-sulfamethoxazole, I put her on clarithromycin and levofloxacin. I was unable to find any guidelines or good recommendations for when to obtain EKGs in this setting, so I decided to do an EKG at baseline, and then at days three and 10 of treatment. There was no significant increase in QTc.”

An EIN member in Wisconsin cited a March 2013 article in Antimicrobial Agents and Chemotherapy assessing QTc prolongation in hematology/oncology patients treated with both a fluoroquinolone and azole. Twenty-one percent of the studied patients had clinically significant prolongation of QTc while receiving combination fluoroquinolone-azole therapy.

Another respondent, in Florida, suggested a website, www.azcert.org/index.cfm, maintained by the University of Arizona Center for Education and Research on Therapeutics, an independent academic center whose mission is to improve therapeutic outcomes and reduce adverse events caused by drug interactions and drugs that cause heart arrhythmias.

“Since it’s known that most torsades de pointes (TdP) cases associated with non-cardiac drugs have risk factors, I usually do a risk assessment,” wrote a member in Iowa, citing a July 2003 article in the journal Medicine. “I look at both the proarrhythmic potential of the antimicrobial (definite, possible, conditional risk, per www.azcert.org/medical-pros/drug-lists/bycategory.cfm) and the patient's concomitant risk factors, in descending order of frequency,” per the Medicine article:

  1. Female gender (after puberty)
  2. Heart disease, defined as myocardial infarction, heart failure, valvulopathy, or cardiomyopathy
  3. Hypokalemia (potassium serum levels <3.5 meq/L)
  4. Drug toxicity (higher than recommended dosages or patients with impaired drug metabolism)
  5. Drug interactions (concurrent therapy with another QT interval-prolonging drug (amiodarone or antidepressant) or with a drug inhibiting the metabolism of the antimicrobial
  6. Family history of long QT syndrome, history of drug-induced TdP, or QT interval prolongation in absence of drugs

The member suggested doing an EKG in patient “with one of the above risk factors before starting an antimicrobial with definite evidence of TdP (like azithromycin, clarithromycin, moxifloxacin, pentamidine, etc.). If the patient is also on QT-prolonging drugs, I would get an on-drug EKG the next day.”

The member added, “The most difficult decision to me is about voriconazole, which is where I have been called most often, because of a single case report of a female teen with concentration-independent torsade,” published in the Sept. 15, 2004, issue of Clinical Infectious Diseases.


E-mail the Emerging Infections Network.

The Emerging Infections Network (EIN) is a provider-based sentinel network designed to help the public health community detect trends in emerging infectious diseases.

A joint project of IDSA and the Pediatric Infectious Diseases Society (PIDS) with funding from the Centers for Disease Control and Prevention (CDC), EIN tracks emerging infectious diseases and keeps the public health community up to date with new disease trends, difficult cases, and other issues affecting members’ clinical practices. The Network provides a great opportunity for members to share knowledge quickly across large geographical distances. Both IDSA and PIDS members are eligible to join. Click here for more information or to join EIN.