Intrathecal Drug Delivery
Intrathecal Drug Delivery (IDD) Overview
For those suffering from chronic pain, IDD or an intrathecal drug delivery system, can offer renewed hope. The spinal cord is rich with Opioid receptors, along with Sodium, Calcium, adrenergic, NMDA and GABA receptors, all of which are involved in the modulation of pain. IDD takes advantage of these “local” receptors with delivery of the analgesic directly into the intrathecal space or spinal fluid. With the very small amounts of medication necessary with this technique (1mg per day intrathecal Morphine—the most commonly utilized agent -- is equivalent to more than 300mg of oral morphine) systemic and central nervous system side effects can be significantly reduced. In addition to Morphine, other FDA approved intrathecal drugs include clonidine (Duraclon), ziconotide (Prialt is a N type Calcium channel blocker), baclofen and local anesthetics. Dilaudid or hydromorphone is also commonly used. Numerous other medications are under development.
The Implantation Technique
Prior to surgical implantation, an epidural or intrathecal trial of the proposed medication is accomplished generally as an inpatient. The trial, accomplished with a temporary catheter placed percutaneously, can last as little as 24 hours or as long as one week depending on the receptor targets and agents used. Trial is deemed successful if the patient reports more than 50% pain relief. During the trial, any oral pain medications are reduced by half or more, to ensure accurate reporting of pain relief. Placement of the permanent infusion system is then scheduled electively.
Permanent implant of the infusion system, consisting of a single piece intrathecal catheter and a programmable pump or reservoir, is generally accomplished under a combination of local and spinal anesthesia, though general anesthesia is also an option. The procedure generally takes less than one hour. Overnight stay in a hospital is required for monitoring of the new system.
The newest Synchromed infusion pump by Medronics offers 20 or 40ml reservoirs. These new pumps often allow refills spaced as far as six months apart, making the IDD both convenient and therapeutic. Additionally, there is a patient control feature that allows the delivery of additional medication on demand, within the prescribed limits.
Who can benefit from IDD
The indications for IDD are extensive, and include pain of visceral origin, somatic, neuropathic and cancer pain. The only requirement is verifiable pathology as the cause of the pain and failure of more conservative pain management measures to reduce or control the pain.
CC4PM physicians currently provide IDD therapy to well over 100 patients currently under our pain management program. If you are interested in learning more about this therapy option, or believe that an intrathecal drug delivery system may be right for your chronic pain, please ask your CC4PM physician about it at your next scheduled appointment, or call us (419) 843-1370.