Intrathecal drug delivery maintenance: Refill and programming

Abstract

Treatment of noncancer pain with intrathecal opioids in patients with chronic intractable pain has been an important breakthrough in the pain management field over the past four decades [1]. It has been increasingly used in patients with chronic intractable pain in whom conservative therapies have failed, or those who cannot tolerate side effects of oral opioid medications. Delivering opioids within the cerebrospinal fluid allows the administration of only a small amount of opioid to provide analgesia without the overt systemic side effects that may be experienced when the drugs are given orally or intravenously. A number of reviews have documented the safety and efficacy of intrathecal drug delivery (IDD) therapy in patients with chronic pain. IDD therapy for noncancer pain is effective, cost-neutral, and appropriate [1]. Although the overall safety of IDD systems has been documented, there have been case reports of adverse events. Most notably, respiratory depression with concomitant use of central nervous system depressant medications such as benzodiazepines has been implicated in IDD-related fatalities [1]. Potential problems also can occur during the pump refill, such as a pocket fill. Although respiratory depression is rare in patients who are opioid tolerant, missed refill dates may predispose the patient to an opioid-naïve state in which a medication refill of morphine at the same concentration and dose may result in delayed respiratory depression [2]. (Early respiratory depression has not been reported with morphine.) A number of other important matters need particular care and attention during the refill and maintenance process to avoid likely complications. Proper physician training and understanding of the pharmacology and dosing of intrathecal medications is imperative to limit life-threatening complications including pocket fills and respiratory depression.