Massive clonidine overdose during refill of an implanted drug delivery device for intrathecal analgesia: a review of inadvertent soft-tissue injection during implantable drug delivery device refills and its management.

OBJECTIVES: The study aims to highlight the potentially serious consequences of inadvertent soft-tissue injection of intrathecal drugs such as clonidine, during refills of implanted drug delivery devices, and to suggest strategies to reduce this complication. DESIGN: Case report and literature review were used. RESULTS: We report the case of a 51-year-old female with chronic arm pain who sustained a massive clonidine overdose (18,000 mcg) due to inadvertent soft-tissue injection during a refill of an implanted drug delivery device, resulting in rapid loss of consciousness and significant cardiovascular instability requiring urgent resuscitation, subsequent myocardial infarction, cardiac failure, and other significant complications. The risks of inadvertent soft-tissue injection of intrathecal drugs during implanted drug delivery device refills and management of such events is poorly documented in the literature. CONCLUSION: Inadvertent soft-tissue injection is possibly an underappreciated and underreported complication of intrathecal analgesia via an implanted drug delivery device. Under some circumstances, large doses of other intrathecal drugs such as bupivacaine, opioids, ziconotide, and baclofen may also be delivered by inadvertent soft-tissue injection with potentially life-threatening consequences. We recommend that practitioners, institutions, and professional bodies who manage patients with intrathecal analgesia via intrathecal drug delivery devices highlight and audit this complication and develop systems to manage it.