Audit and Service Evaluation 20 Years Experience of Ziconotide Therapy in Leeds, UK.

Black S.; Farquhar E.; Jennings J.; Titterington J.

Audit and Service Evaluation 20 Years Experience of Ziconotide Therapy in Leeds, UK.

All Authors

Black S.

Farquhar E.

Jennings J.

Titterington J.

LTHT Author

Black, Sheila
Farquhar, Elisabeth
Jennings, Jenny
Titterington, John

LTHT Department

Theatres & Anaesthesia
Anaesthetics
Pain Management
Medicines Management & Pharmacy Services
Clinical Pharmacy
Neurosciences
Spinal Services

Non Medic

Advanced Clincal Pharmacist For Chronic Pain Management
Pain Nurse Specialist

Publication Date

2024

Item Type

Conference Abstract

Subject

ANALGESICS , CLINICAL AUDIT , PAIN MANAGEMENT

Abstract

BACKGROUND: Ziconotide is an analgesic agent for neuropathic and nociceptive pain, delivered intrathecally. It has benefits over intrathecal opioids and local anaesthetic agents, including lack of tolerance, or risk of withdrawal; less logistical issues due to it not being a controlled drug; it is a licensed drug with a secure supply chain. However, there are few large studies and lack of experience in UK pain centres of long-term use of this agent, due to restriction of use. Despite recent relaxation of these restrictions, there can be reluctance to adopt this therapy due to lack of familiarity or guidance on dosing schedules. AIMS: We share our centre's experience in patient selection, commencement and adjustment of dosing, side-effects and stability of therapy. As this data spans 20 years, it includes the experience of the current team, and that of our predecessors. METHOD(S): Electronic hospital records, local clinic databases and pharmaceutical records were searched to identify those who received ziconotide injection or infusion via intrathecal pump. Local commissioning records were analysed to identify patients who had individual funding request (IFR) for ziconotide therapy accepted or rejected. RESULT(S): In total, 19 patients received ziconotide therapy in our service during 2004-2024. Indications included a variety of pain conditions: post-surgical back pain, CRPS, pelvic pain, post-stroke central neuropathic pain, spinal cord injury, spinal trauma/infection, lumbar spondylosis, myeloma, bowel cancer, osteogenesis imperfecta, post spinal/pelvic trauma, acoustic neuroma. Sixteen patients had intrathecal pump implanted, of which ten had ziconotide first in the pump. Six were switched over from combinations of hydromorphone/diamorphine, bupivacaine and clonidine. Five patients had a single-shot test of 2.5mcg before decision to implant the pump. Initial starting doses ranged from 1.2-2.5mcg per day, except for one patient who we inherited into our service already established on a dose of 8mcg/day. Doses were titrated up as tolerated, with the commonest limitation being neurological side effects such as slurred speech and dizziness. Maintenance doses ranged from 1.6mcg per day to 17.7 mcg per day, mean dose 9.14mcg per day. Twelve patients had successful therapy, of which six continue the therapy to the current day. Five patients died whilst benefitting from ziconotide infusion, duration of therapy ranging from 8 months to 9 years. One patient received infusion for 7 years before it was discontinued on balance of side effects compared with pain relief. Four patients commenced but did not continue the therapy, duration ranging from 2 months to 1 year. All suffered neurological side effects including headache, dizziness, depression and confusion. Four patients only had a singleshot trial injection of ziconotide, of 2.5mcg, of which two patients had poor response to the drug; one had good response but opted for spinal cord stimulation instead; one had good response but IFR was denied. Five patients commenced ziconotide from 2004-2008. From 2009 onwards, IFR was required to commence ziconotide therapy. During 2009-2014, 13 IFR's were requested of which 12 were granted. Following NHS England change to not for routine commissioning from 2014-2017 four applications IFR requests were made directly to NHS England though none were granted on basis of lack of exceptionality and need for clinical psychology input. We currently have 6 ziconotide patients, 4 male, 2 female. The longest duration of therapy is 20 years, since 2004. Average duration for therapy is 14.5 years. Five patients are extremely stable on their maintenance dose. One patient requires adjustment of dose according to mental health issues which pre-date the start of ziconotide, achieving a balance of pain relief against risk of psychotic symptoms. CONCLUSION(S): We demonstrate the safe and effective use of ziconotide in 19 patients over a 20 year period.