Warning about cybersecurity; constipation drug approved

This column reviews details on recent recalls, warnings, and approvals.

Recalls and warnings

A warning that St. Jude Medical's radio frequency-enabled implantable cardiac devices and Merlin@@home transmitter have potential cybersecurity vulnerabilities. If exploited, such vulnerabilities could allow an unauthorized user to remotely access a patient's device by altering the transmitter. Programming commands could then be modified, resulting in rapid battery depletion and/or inappropriate pacing or shocks. The manufacturer has applied a software patch to the transmitters, and the FDA has ensured that the patch reduces the risk of exploitation and subsequent patient harm. There have been no related reports of patient harm.


Plecanatide (Trulance) to treat adult patients with chronic idiopathic constipation. The oral medication is taken once per day and works in the upper gastrointestinal tract to stimulate secretion of intestinal fluid, supporting regular bowel function. Safety and efficacy were demonstrated in two 12-week, placebo-controlled trials of 1,775 participants diagnosed with constipation. Those who received the medication were more likely than those who received placebo to experience improvements in stool frequency, consistency, straining, and the frequency of complete spontaneous bowel movements. The most common side effect was diarrhea, and patients should stop taking the medication and contact their clinician if severe diarrhea occurs. The medication should not be used in patients under 18 years or those with known or suspected mechanical gastrointestinal obstruction.

Art 1

The G5 Mobile Continuous Glucose Monitoring System to be used without confirmation from traditional fingerstick blood glucose testing. Prior to the expanded approval, the system (which still requires calibration with at least two fingersticks per day) was approved to complement, not supplant, fingerstick testing. In effect, the approval allows patients ages 2 and older and their clinicians to use results directly from the device to make diabetes treatment decisions. The device measures and monitors glucose levels with a small, subcutaneous sensor wire and provides real-time results every five minutes. The new approval is based on the results of two clinical trials of 130 patients that over a seven-day period compared the system's readings with blood glucose meter values and a laboratory test method that measures glucose values. Risks include hypoglycemia or hyperglycemia if results are inaccurate, as well as skin irritation or redness around the adhesive patch.


A safety communication about reports of serious adverse events, including patient injury and death, associated with implantable infusion pumps in the magnetic resonance imaging (MRI) environment. The reports describe dosing inaccuracies (e.g., over- or under-infusion, unintended bolus) and mechanical problems with the pump (e.g., motor stall, pump not restarting after MRI). The only implantable infusion pumps that may be used safely in the magnetic resonance environment are labeled as MR Conditional, and specific instructions vary by make and model. The FDA is working with manufacturers to update MRI safety information in their device labeling to ensure safe use.