Intrathecal Analgesia for Chronic Refractory Pain: Current and Future Prospects.
The intrathecal drug-delivery system (IDDS) is one mode of infusing analgesic medications directly into the cerebrospinal fluid in close proximity to their site of action. This modality has been employed in patients with refractory pain either due to malignant or non-malignant causes for over 30 years. Unfortunately, and despite the number of years it has been in use, there is still a scarcity of rigorous evidence to guide its integration into clinical practice. Current best evidence is inconclusive as to the comparative effectiveness and harms of the IDDS relative to routine medical care of patients. There are far more systematic reviews than high-quality primary comparative studies of the IDDS vs. conventional pain treatment. Existing clinical practice recommendations are best viewed as expert opinion with competing interests. This article will review the existing literature for indications, contraindications, consensus statements, different technologies, and complications of the IDDS. Although approved analgesics for IDDS delivery are limited to morphine and ziconotide, many other analgesics, alone or in combination, are routinely used in this setting. This review will also focus on the pharmacology, clinical efficacy, and safety of intrathecal medications extensively used in clinical practice; including agents approved, unapproved, and under development.
Department of Anesthesiology, University of Ottawa and Ottawa Hospital Research Institute, The Ottawa Hospital-General Campus, 501 Smyth Rd., CCW 1551, Ottawa, ON, K1H 8L6, Canada. csmyth@toh.on.ca.
Catherine
C
Smyth
Knowledge Synthesis Group, Ottawa Hospital Research Institute, Ottawa, ON, Canada.
Nadera
N
Ahmadzai
Department of Pharmacy, The Ottawa Hospital, Ottawa, ON, Canada.
Jason
J
Wentzell
Department of Anesthesiology, University of Ottawa, The Ottawa Hospital-General Campus, 501 Smyth Rd., CCW 1551, Ottawa, ON, K1H 8L6, Canada.
Ashley
A
Pardoe
Department of Anesthesiology, University of Ottawa, The Ottawa Hospital-General Campus, 501 Smyth Rd., CCW 1551, Ottawa, ON, K1H 8L6, Canada.
Andrew
A
Tse
Department of Pharmacy, The Ottawa Hospital, Ottawa, ON, Canada.
Tiffany
T
Nguyen
Department of Anesthesiology, University of Ottawa, The Ottawa Hospital-General Campus, 501 Smyth Rd., CCW 1551, Ottawa, ON, K1H 8L6, Canada.
Yvette
Y
Goddard
Department of Anesthesiology, University of Ottawa, The Ottawa Hospital-General Campus, 501 Smyth Rd., CCW 1551, Ottawa, ON, K1H 8L6, Canada.
Shona
S
Nair
Departments of Anesthesiology and Psychology, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada.
Patricia A
PA
Poulin
, Ottawa, Canada.
Becky
B
Skidmore
Faculty of Medicine, School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, ON, Canada.
Mohammed T
MT
Ansari
D000700:Analgesics / Q000008:administration & dosage* / Q000627:therapeutic use; D000075202:Contraindications; D004864:Equipment and Supplies; D006801:Humans; D007278:Injections, Spinal / Q000009:adverse effects / Q000379:methods / Q000592:standards; D008959:Models, Neurological; D059408:Pain Management / Q000379:methods*; D010148:Intractable Pain / Q000188:drug therapy*
D000700:Analgesics