BETHESDA, MD 09 November 2012—Minneapolis-based Medtronic Inc. wants pharmacists and physicians to know that using the Synchromed implantable infusion pump system to deliver drugs that are not specifically approved for the device can result in pump failure and serious adverse events.
According a Dear Healthcare Professional Letter" and related documentation, the only medications compatible with the pump are Lioresal intrathecal baclofen injection, Gablofen intrathecal baclofen injection, Infumorph intrathecal morphine sulfate injection, and Prialt intrathecal ziconotide solution. Also approved are intravascularly administered floxuridine and methotrexate solutions.
The letter describes the maximum drug concentrations for use with the pump and the appropriate use of diluents and flush solutions.
Unsafe medications for the pump include anything not on the above list, including pharmacy-compounded drugs and admixtures.
According to Medtronic, the use of unapproved drugs may lead to gear corrosion that causes the pump's motor to stall. Motor stalls may also occur during normal use, but the problem is much greater when the pump is used to deliver unapproved medications.
The failure rate for Synchromed pumps after 72 months of use is 2.8% when approved drugs are used with the device and 7% when unapproved drugs are used, according to the company.
Robert J. Coffey, medical advisor for Medtronic's Neuromodulation division, said physicians whose patients use the Synchromed pump for intrathecally administered drugs typically note the route of administration on prescriptions for the drugs. He said approved intrathecal drugs are supplied in special kits that are easy for a pharmacist to recognize.
He also said that a prescription for an unapproved medication should stand out to pharmacists because of the large volume of medication that is delivered by the pump before it needs a refill.
"No outpatient entity that I can imagine would order, under a single patient's name, a 40-mL syringe of morphine" unless it is intended for administration through a pump, Coffey said.
Medtronic Neuromodulation Quality Assurance Engineer Andrew Rennie confirmed that the letter is part of a the company's response to an FDA investigation that led to a warning letter this past July.
The warning letter declared that the Medtronic's neurologic medical and surgical devices are adulterated because the company did not follow current good manufacturing practice requirements.
FDA specifically called out problems with steps the company had taken to reduce the risk of pump corrosion and device failure and to communicate risk information to health care providers. FDA requested a September 12 meeting with company officials to discuss the agency's findings.
Rennie said Medtronic decided before the meeting to craft a "Dear Healthcare Professional" letter and has since shared with FDA the company's plan for communicating risks about the pumps. He said physicians should begin receiving the letters next week.