Medical device maker Medtronic PLC said two people have died following dosing errors with its problem-plagued SynchroMed II infusion pump, an implanted device made in Minnesota that slowly injects pain medications into a patient's spinal canal.
More than 238,000 of the devices have been implanted in patients with advanced metastatic cancer, chronic pain and severe spasticity. Various problems with the device have been linked to more than a dozen deaths in recent years. The Food and Drug Administration filed a consent decree against Medtronic in 2015 for repeated failures to correct manufacturing problems.
On Tuesday, regulators in the United Kingdom published an update from Medtronic on the specific problem of "overinfusion," which happens when the programmable SynchroMed II puts out more pain medication than intended.
The issue of overinfusion was first disclosed in March 2014. A three-page update published online Tuesday by the U.K.'s Medicines and Healthcare Products Regulatory Agency said an ongoing analysis by Medtronic has concluded two patients have died and 103 pumps were affected by issues that led to overinfusion of pain drugs through July 5, 2016.
"Medtronic has been unable to establish a definitive causal relationship between the adverse events and overinfusion, due to potential contributing factors. However, it is reasonable to conclude that overinfusion was a contributing factor," Medtronic's letter to doctors on the overinfusion issue said.
The other contributing factors include the dosage of the infused drug, patient medical history, and simultaneous use of other drugs including oral opioids, the letter said. Of the 103 pumps linked to adverse events, 99 of the devices were filled with "non-indicated" drug formulations the last time the pumps' reservoirs were refilled.
Medtronic recommends using only approved drugs and concentrations in the pumps, and to examine patients for signs of overdose or withdrawal during refill appointments. Withdrawal from medication is a potential issue because overinfusion can potentially deplete the pump's reservoir without setting off the device alarm, causing the drug to stop flowing unexpectedly.
The company does not recommend removing the device without first seeing signs of problems.
Medtronic's neuromodulation division, which makes the devices, is based in Columbia Heights.
Last year, Medtronic CEO Omar Ishrak signed an FDA consent decree, which was similar to a legal settlement but required ongoing monitoring of the company and placed tight controls over when doctors can prescribe a SynchroMed II pump.
The consent decree came after a series of FDA recall notices in 2013 about different issues with the device associated with 14 deaths at the time, including one in Minnesota.
The biggest risk among those four issues was linked to a problem that led doctors to inject pain drugs into the tissue near the pump, rather than into the pump itself, during refills; 11 deaths were associated with that at the time. Two more patients died after problems with misalignment of the drug-delivery tube and the pump's connection site, and another person died after a potential electrical short caused a loss of therapy.
The company has repeatedly counseled doctors on the best ways to use the pumps and avoid problems.