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Smartphone app offers online access to QT-prolonging drugs database
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CredibleMeds has released a free smartphone app to help physicians, pharmacists, nurses and other health care providers manage the overwhelming amounts of information on drugs that prolong the QT interval and increase the risk for torsades de pointes arrhythmia and sudden death. The app is available in iOS, Android and Windows Mobile formats and makes CredibleMeds’ online “QTdrugs” database instantly available and always up-to-date.
Supported by a contract from the FDA, CredibleMeds independently analyzes all available evidence and places drugs into categories based on the evidence supporting their association with QT interval prolongation and torsades de pointes (TdP). The QTdrugs database lists more than 135 QT-prolonging medicines that have some potential for causing life-threatening TdP and another 85 that carry this risk but only under certain clinical conditions (eg, drug overdose, congenital long QT syndrome [cLQTS], drug interactions, etc). These lists are regularly accessed by more than 85,000 registered visitors to the CredibleMeds website (www.CredibleMeds.org, www.torsades.org or www.QTdrugs.org).
Source: CredibleMeds; printed with permission.
The development of a mobile platform for the QTdrugs lists greatly expands access to this critical information for the safe use of medicines. The app has an advanced search feature so users can easily enter the name of a drug to determine whether it is in one of four TdP risk categories. Also, for each drug, the app provides a direct link to the National Library of Medicine’s PubMed service to display a list of articles using search terms for the specific drug and “QT or Torsad*.”
TdP risk categories
Because TdP can occur under a variety of conditions and the evidence is often incomplete, CredibleMeds places the drugs in the QTdrugs database in one of four categories.
Drugs with “known risk of TdP” are those for which there is conclusive evidence that, when administered as recommended in the drug’s FDA-approved label, they can cause TdP.
Drugs found to prolong the QT interval but which lack convincing evidence of TdP are classified as having a “possible risk of TdP.”
The “conditional risk” category includes drugs found to have a risk for TdP but only under certain specific conditions, such as overdose, hypokalemia, hypomagnesemia, bradycardia or when there is an interaction with another drug(s) that can induce TdP. This category also includes drugs that are associated with TdP because they have pharmacologic actions that create the conditions that enable another drug to cause TdP (eg, loop diuretics or metabolic inhibitors of a QT-prolonging drug).
The fourth category is those drugs that have special risk for TdP for patients with cLQTS due to their ability to prolong QT or activate the adrenergic nervous system.
Features of the smartphone app
There are two general aspects to the information in the app. The first, “Drugs and LQTS,” focuses on drug-induced TdP and the drugs responsible. The second, “Congenital LQTS,” focuses on the special risk of some drugs for patients with cLQTS. As shown the Figure, the app’s menu lists:
Drugs and LQTS
- descriptions of the TdP risk categories to explain their differences;
- searchable list of all drugs in the QTdrugs database;
- the drug’s primary medical indication;
- major brand names (partial list);
- TdP risk category;
- route(s) of administration associated with risk; and
- PubMed link for instant search of medical literature for relevant articles.
Congenital LQTS
- information on cLQTS and drugs to avoid — explanation of risk categories;
- A searchable list of all drugs to avoid for patients with cLQTS; and
- background medical information on LQTS, prolonged QT, TdP and FAQs.
Clinical uses for providers
The app is especially useful when one needs to quickly ascertain whether a medicine may cause harm to a patient, especially one known to be at increased clinical risk for TdP (ie, a patient with hypokalemia, hypomagnesemia, bradycardia, cLQTS, sepsis, structural heart disease, female sex, etc). It is also very helpful when one is trying to identify which one (or more) of the many medications on a patient’s drug list is responsible when the patient has developed a prolonged QT or TdP.
This tool should be especially useful for those who are conducting medication reconciliation, because QT drug interactions is one of the CMS quality measures being implemented in 2017.
Uses for patients, family members
Because patients receive prescriptions from many physicians, cardiologists may want to recommend that their patients with congenital long QT or their family members use the app to check any new medicine they might consider taking. Approximately 30,000 patients and family members worldwide regularly download a copy of the list of “Drugs to Avoid in cLQTS.” Now, cardiologists and other health care providers can recommend that their patients use the app and remove the possibility of using outdated lists. Nearly 10,000 apps were installed in the first month, mostly due to endorsement by the Sudden Arrhythmic Death Syndromes (SADS) Foundation.
- Reference:
- Woosley RL, et al. Drug Safety. 2017;doi:10.1007/s40264-017-0519-0. For more information:
- Raymond L. Woosley, MD, PhD, is professor of biomedical informatics and medicine and Flinn Foundation Visiting Scholar at the College of Medicine-Phoenix at the University of Arizona. Woosley is also a member of Practice Management and Quality Care section of the Cardiology Today Editorial Board. He can be reached at rwoosley@azcert.org.
Disclosure: Woosley reports no relevant financial disclosures.