The FDA on November 14 issued a "safety communication" to prescribers and patients reminding them that only 2 drugs are approved for use in implanted intrathecal pumps, and that any other drugs, including any compounded drugs, could lead to serious complications and even damage the tubing and other components of the pump system.1
The FDA issued this safety communication after reviewing medical device reports, premarket device applications, mandated FDA postapproval studies, publicly available scientific literature, current device labeling, and information from health care providers and device manufacturers.2
Patients and providers, who experience an adverse event due to an implanted pump or suspect an infusion pump is having problems, are encouraged to file a voluntary report through MedWatch, the FDA Safety Information and Adverse Event Reporting program.
That Leaves Only Two Choices-or Sometimes Just One
The FDA has approved only 2 drugs for use in intrathecal pumps. The safety communication contained Table 1, showing those 2 drugs, and examples of drugs that have been used off-label in the pumps for patients who did not find enough relief or suffered side effects from the 2 approved drugs.
For patients who have not had pain relief from other less invasive approaches, implanted pumps are surgically inserted under the skin and connected to an implanted catheter to deliver medicines into the spinal fluid to manage pain. Complications may include dosing errors, pump failure, opioid withdrawal, infection and other complications, such as pain, fever, vomiting, muscle spasms, cognitive changes, weakness, and cardiac or respiratory distress.
"The treatment of pain has become increasingly complex," said Scott Gottlieb, MD, commissioner of the FDA, in a press release.2
"While medical devices, such as implanted pumps that deliver medication directly into the spinal fluid, have the potential to play an important role in treating pain, their use must be judicious and their instructions for use must be carefully followed," Gottlieb said.
"This is especially true when it comes to implantable pumps that deliver analgesic medicine directly into the nervous system," he continued. "We urge health care providers, patients and caregivers to be aware of the information the FDA is providing today so they can make informed treatment decisions. The FDA will continue to monitor the safety of these and other medical devices involved in the treatment of pain, and take action where needed to protect patients."
Implanted pumps require a health care provider to periodically refill the pump with medication. Currently, the FDA-approved implanted pump labeling (Instructions for Use) identifies pain medicines that have been evaluated by the FDA for compatibility with the pump, including Infumorph and Prialt (not all pumps are currently approved for use with Prialt).
The FDA has found that patients are sometimes being treated with medications that are not approved (including compounded medicines, hydromorphone, bupivacaine, fentanyl, and clonidine) for use with an intrathecal implanted pump. The reasons sometimes cited for the use of drugs not approved for use with implanted pumps have included that approved medications listed in the pump labeling may have undesirable side effects or may fail to deliver adequate pain relief for some patients.2
"The FDA has determined that implantable intrathecal pump failure is more frequent with the use of medicines not approved for use with the pump. For example, some medicines or fluids may contain preservatives or other characteristics that can damage the pump tubing or lead to corrosion of the pumping mechanism," according to the FDA press release.
"This may cause the implanted pump to perform in unexpected ways, including motor stalls, which ultimately stop the medication delivery, leading to potential opioid withdrawal," according to the press release.
When a pump fails, patients must undergo surgery to remove or replace the pump.
Dosage errors may also occur, because programmable implanted pumps have dose calculation software that provides options for users to select preprogrammed medicines and concentrations identified in the approved pump labeling to help prevent unintended dosing errors, according to the FDA. The accuracy of the software calculations depends on using the approved medicine. For example, if there is more than one medicine in the pump reservoir, the pump software can only calculate the dose based on the infusion rate of a single medicine, according to the FDA.
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