Intrathecal inflammatory masses: is the yearly opioid dose increase an early indicator?

Intrathecal drug delivery for the management of pain and spasticity in adults: British Pain Society's recommendations for best clinical practice

The British Pain Society updated their recommendations on intrathecal drug delivery (ITDD) for the management of pain and spasticity in adults. The recommendations are primarily evidence based but where necessary comprise the consensus opinion of the working group. The recommendations are accompanied by information for patients and their carers, intended to inform and support patients in their decision making. The updated guidance includes recent evidence base of ITDD use in pain and spasticity, address the issues of drug pump compatibility following the latest manufacturer and Medicines and Healthcare products Regulatory Agency (MHRA) recommendations as well as provide an update on the indications and complication management particularly endocrine complications and intrathecal granuloma formation.

Symptomatic Intrathecal Catheter Tip Granuloma Formation With Ultralow-Dose and Low-Concentration Morphine Infusion: A Case Report and Review of Literature

OBJECTIVES

This study aimed to describe catheter tip granuloma (CTG) formation in a patient on ultralow-dose, low-concentration morphine via intrathecal (IT) drug delivery system (IDDS) and to review literature for reports of IT granuloma formation and association with drug type, drug dose, and drug concentration.

MATERIALS AND METHODS

This review describes diagnosis and management of a patient with CTG on ultralow-dose, low-concentration morphine. PubMed data base search was conducted from January 1990 to July 2021 for original articles on CTG formation in humans getting intrathecal analgesics. Data were extracted on indications for IDDS, time to detect CTG, and type of drug/s with drug doses and concentrations. Percentages and average with range for age, sex, duration of infusion, drug doses, and drug concentrations were calculated.

RESULTS

We describe CTG formation and spinal cord compression with worsening of sensorimotor deficits in a patient receiving intrathecal morphine at ultralow dose (0.6 mg/d) and low concentration (1.2 mg/mL), which is the lowest reported morphine dose associated with CTG in the literature. Our literature review shows all IT drugs have the potential for granuloma formation, and there is no drug with granuloma-inhibiting effect.

CONCLUSIONS

There is no drug, dose, or concentration that has granuloma-sparing effect. It is imperative to maintain vigilance for potential CTG in all patients with IDDS. Routine monitoring and prompt evaluation for any unexplained symptoms or change in neurologic status from baseline is critical in early detection and treatment of CTG.

Intrathecal Drug Delivery: Advances and Applications in the Management of Chronic Pain Patient

Advances in our understanding of the biology of spinal systems in organizing and defining the content of exteroceptive information upon which higher centers define the state of the organism and its role in the regulation of somatic and automatic output, defining the motor response of the organism, along with the unique biology and spatial organization of this space, have resulted in an increased focus on therapeutics targeted at this extracranial neuraxial space. Intrathecal (IT) drug delivery systems (IDDS) are well-established as an effective therapeutic approach to patients with chronic non-malignant or malignant pain and as a tool for management of patients with severe spasticity and to deliver therapeutics that address a myriad of spinal pathologies. The risk to benefit ratio of IDD makes it a useful interventional approach. While not without risks, this approach has a significant therapeutic safety margin when employed using drugs with a validated safety profile and by skilled practioners. The present review addresses current advances in our understanding of the biology and dynamics of the intrathecal space, therapeutic platforms, novel therapeutics, delivery technology, issues of safety and rational implementation of its therapy, with a particular emphasis upon the management of pain.

Intrathecal Therapy for Chronic Pain: A Review of Morphine and Ziconotide as Firstline Options

Objectives

To evaluate the evidence for morphine and ziconotide as firstline intrathecal (IT) analgesia agents for patients with chronic pain.

Methods

Medline was searched (through July 2017) for “ziconotide” or “morphine” AND “intrathecal” AND “chronic pain,” with results limited to studies in human populations.

Results

The literature supports the use of morphine (based primarily on noncontrolled, prospective, and retrospective studies) and ziconotide (based on randomized controlled trials and prospective observational studies) as first-choice IT therapies. The 2016 Polyanalgesic Consensus Conference (PACC) guidelines recommended both morphine and ziconotide as firstline IT monotherapy for localized and diffuse chronic pain of cancer-related and non–cancer-related etiologies; however, one consensus point emphasized ziconotide use, unless contraindicated, as firstline IT therapy in patients with chronic non–cancer-related pain. Initial IT therapy choice should take into consideration individual patient characteristics (e.g., pain location, response to previous therapies, comorbid medical conditions, psychiatric history). Trialing is recommended to assess medication efficacy and tolerability. For both morphine and ziconotide, the PACC guidelines recommend conservative initial dosing strategies. Due to its narrow therapeutic window, ziconotide requires careful dose titration. Ziconotide is contraindicated in patients with a history of psychosis. IT morphine administration may be associated with serious side effects (e.g., respiratory depression, catheter tip granuloma), require dose increases, and cause dependence over time.

Conclusion

Based on the available evidence, morphine and ziconotide are recommended as firstline IT monotherapy for cancer-related and non–cancer-related pain. The choice of first-in-pump therapy should take into consideration patient characteristics and the advantages and disadvantages of each medication.

Unique Intradural Inflammatory Mass Containing Precipitated Morphine: Confirmatory Analysis by LESA-MS and MALDI-MS

Opioids are often used for analgesia via continuous intrathecal delivery by implantable devices. A higher concentration and daily dose of opioid have been postulated as risk factors for intrathecal granuloma formation. We present a 42-year-old female patient with chronic abdominal pain from refractory pancreatitis, with an intrathecal drug delivery device implanted 21 years prior, delivering continuous intrathecal morphine. After many years without concerning physical signs or complaints, with gradual increases in daily morphine dose, she presented with rapidly progressive neurologic deficits, including lower extremity, bladder, and bowel symptoms. These symptoms were determined to be secondary to mass effect and local inflammation related to an intrathecal catheter tip granuloma, detected on magnetic resonance imaging of the spine. The mass was urgently resected. On histopathologic examination, this granuloma was found to be unique, in that in addition to the expected inflammatory components, it appeared to contain precipitated nonpolarizable crystals. These were identified as precipitated morphine using liquid extraction surface analysis-tandem mass spectrometry (LESA-MS/MS) and matrix-assisted laser desorption ionization-Fourier transform ion cyclotron resonance-mass spectrometry imaging (MALDI-FTICR-MSI). In addition to the unique finding of precipitated morphine crystals, the long-term follow-up of both morphine concentration and daily dose increases provides insight into the formation of intrathecal granulomas.

Comparison of the Effects of Intermittent Boluses to Simple Continuous Infusion on Patients' Global Perceived Effect in Intrathecal Therapy for Pain: A Randomized Double-Blind Crossover Study

Objective

Intrathecal drug delivery (ITDD) is commonly used for intractable pain management. A paucity of good-quality studies in chronic noncancer patients and concerns over increased dosages have focused interest on different modes of administration. The aim of this international multicenter randomized double-blind crossover trial was to compare the efficacy of the same daily dose of drugs administered by intermittent boluses vs simple continuous infusion.

Methods

Eligible patients implanted with a programmable ITDD device were randomized to receive two weeks of either intermittent boluses or a simple continuous flow in period 1, followed by a crossover to the alternative mode of administration. The primary outcome measure was the Patients' Global Impression of Change (PGIC) scale.

Results

The mean proportion of positive responders (at least "minimally improved") was 38.4% in the continuous condition vs 37.3% in the bolus (difference in proportions = 1.1%, 95% confidence interval [CI] = -21.8-24.0%, P  = 0.93). The mean PGIC in the continuous condition was 3.8 vs 3.9 in the bolus (mean difference = -0.1, -0.6-0.4, P  = 0.72). Exploratory analyses revealed a tendency for the mean proportion of positive responders to be higher at low vs high flow rates for both bolus and continuous administrations. Two patients were withdrawn from the study due to adverse events during the bolus phase, both with symptoms of increased pain, and one patient with additional symptoms of numbness and urinary retention.

Conclusion

The mean PGIC and proportion of positive responders was not substantially different after intermittent bolus vs continuous administration.

Primary Hydromorphone-Related Intrathecal Catheter Tip Granulomas: Is There a Role for Dose and Concentration?

BACKGROUND

Intrathecal drug delivery therapy has been used effectively in treating patients with intractable chronic pain. The development of an intrathecal catheter tip granuloma (ICTG) related to delivery of intrathecal opiates is a relatively infrequent, but potentially devastating complication. While there are many morphine-related ICTG cases described, reports of hydromorphone-related ICTG are limited. In addition, studies suggest a strong correlation between the use of higher doses and concentrations of intrathecal opiates and ICTG formation.

OBJECTIVE

The objective of this study is to determine the incidence and the association of intrathecal hydromorphone dose, concentration, duration of treatment and concomitant agents with ICTG formation.

STUDY DESIGN

This is a retrospective analysis of 101 consecutive patients implanted with intrathecal infusion delivery devices. Data were collected from chart review, and records of pump refills from the division of Pain Medicine of University Hospitals or outsourced to a home pump refill service.

RESULTS

From a cohort of 101 consecutively implanted patients, 69 were treated with intrathecal hydromorphone and followed up postimplant for an average of 33.5 ± 24 months (range 0-93 months; 95% CI of 27-39 months). The incidence of ICTG in our patient population was 8.7% during this period of time postimplant with mean time to granuloma detection 35.1 ± 7.9 months. Patients developing granuloma (n = 6) were treated with a combination of intrathecal hydromorphone and bupivacaine infusion. Exposure time to intrathecal agents was not different between the granuloma and nongranuloma group. Monthly dose increase of hydromorphone was higher in granuloma group vs. non-granuloma group (58 ± 34 mcg/month n = 6 vs. 25 ± 8 mcg/month n = 63). Four out of six granuloma cases occurred with low dose and concentration of IT hydromorphone (160-370 mcg/day; 0.75-1.0 mg/mL concentration). Intrathecal bupivacaine dose was not different between groups. A subset of patients was treated with intrathecal fentanyl and bupivacaine. No intrathecal granulomas occurred in this patient cohort.

CONCLUSION

This is the first clinical report demonstrating an association of hydromorphone with intrathecal granulomas, particularly at low doses and concentrations of hydromorphone. This study supports the notion that using low dose of IT opioids might not protect against ICTG development but that the level of exposure and type of opioid used in IT space might be highly correlated with ICTG development. Further research and recommendations related to chronic intrathecal opioid infusions are necessary to raise awareness of significant incidence of ICTG and development of tests to isolate patient populations at high risk.

Clinical Uses of Intrathecal Therapy and Its Placement in the Pain Care Algorithm

Intrathecal drug delivery is an effective treatment option for patients with severe chronic pain who have not obtained adequate analgesia from more conservative therapies (eg, physical therapy, systemic opioids, nonsteroidal anti-inflammatory drugs, antidepressants, and anticonvulsants). This review focuses on, but is not limited to, the 2 agents currently approved by the U.S. Food and Drug Administration for intrathecal analgesia: preservative-free morphine and ziconotide (a nonopioid, selective N-type calcium channel blocker). We describe the appropriate use of intrathecal therapy in the management of severe chronic pain, based on current best practices. Topics addressed here include patient selection, trialing, dosing and titration, adverse event profiles, long-term management, intrathecal therapy for cancer-related pain, and the placement of intrathecal therapy in the pain care algorithm. In appropriately selected patients with chronic pain, intrathecal therapy can provide substantial pain relief with improved functioning and quality of life. Successful long-term management requires ongoing patient monitoring for changes in efficacy and the occurrence of adverse events, with subsequent changes in intrathecal dosing and titration, the addition of adjuvant intrathecal agents, and the use of concomitant oral medications to address side effects, as needed. Based on an infrequent but clinically concerning risk of overdose, granuloma, and other opioid-induced complications, nonopioid therapy with ziconotide may be preferred as a first-line intrathecal therapy in patients without a history of psychosis or allergy.

Intrathecal Hydromorphone and Bupivacaine Combination Therapy for Post-Laminectomy Syndrome Optimized with Patient-Activated Bolus Device

BACKGROUND

Intrathecal (IT) pumps have become a valuable tool in managing intractable non-cancer pain. The purpose of this study was to evaluate the efficacy of using a rigorous treatment algorithm for trialing and implanting IT pumps with hydromorphone and bupivacaine in managing a more homogeneous population of post-laminectomy syndrome or failed back surgery syndrome (FBSS) patients.

METHODS

This is a retrospective analysis of FBSS patients with chronic intractable back pain implanted with IT pumps delivering hydromorphone and bupivacaine.

RESULTS

A cohort of 57 (26 males, 31 females) consecutively implanted FBSS patients was analyzed. The average age at implant was 65.4 years. Average pain scores were 8.4 ± 0.2 (pre-implant), 4.9 ± 0.4 (6 months), 5.2 ± 0.5 (12 months), and 4.3 ± 0.5 (24 months). Average oral opioid doses in morphine equivalents were 56 ± 10 mg/day (pre-implant), 12.0 ± 3.5 mg/day (12 months), 15 ± 6 mg/day (24 months). Average IT hydromorphone doses were 79 ± 6.8 mcg/day (at implant), 184 ± 22 mcg/day (6 months), 329 ± 48 mcg/day (12 months), and 487 ± 80 mcg (24 months). IT hydromorphone dose escalation from baseline was 133% (6 months vs baseline), 78% (12 months vs 6 months), and 48% from 12 months to 24 months. Average IT bupivacaine doses were 5.8 ± 0.3 mg/day (implant), 9.5 ± 0.6 mg/day (6 months), 12.2 ± 0.7 mg/day (12 months), and 12.6 ± 0.9 mg/day (24 months).

CONCLUSION

IT hydromorphone and bupivacaine are effective in treating chronic pain of FBSS, as demonstrated by the reduction of pain intensity and oral opioid consumption. However, an IT dose escalation phenomenon was observed, although at a reduced rate compared with what had been previously reported in the literature. It is possible that the local anesthetic combination delivered via a patient-activaed bolus device is an important factor. Despite demonstrating effectiveness, the clinical utility of myPTM-optimized IT therapy remains limited by a lack of prospective, placebo-controlled trials and comparative effectiveness research.

Polyanalgesic Consensus Conference--2012: recommendations to reduce morbidity and mortality in intrathecal drug delivery in the treatment of chronic pain

INTRODUCTION

Targeted intrathecal drug infusion to treat moderate to severe chronic pain has become a standard part of treatment algorithms when more conservative options fail. This therapy is well established in the literature, has shown efficacy, and is an important tool for the treatment of both cancer and noncancer pain; however, it has become clear in recent years that intrathecal drug delivery is associated with risks for serious morbidity and mortality.

METHODS

The Polyanalgesic Consensus Conference is a meeting of experienced implanting physicians who strive to improve care in those receiving implantable devices. Employing data generated through an extensive literature search combined with clinical experience, this work group formulated recommendations regarding awareness, education, and mitigation of the morbidity and mortality associated with intrathecal therapy to establish best practices for targeted intrathecal drug delivery systems.

RESULTS

Best practices for improved patient care and outcomes with targeted intrathecal infusion are recommended to minimize the risk of morbidity and mortality. Areas of focus include respiratory depression, infection, granuloma, device-related complications, endocrinopathies, and human error. Specific guidance is given with each of these issues and the general use of the therapy.

CONCLUSIONS

Targeted intrathecal drug delivery systems are associated with risks for morbidity and mortality that can be devastating. The panel has given guidance to treating physicians and healthcare providers to reduce the incidence of these problems and to improve outcomes when problems occur.

Polyanalgesic Consensus Conference 2012: recommendations for the management of pain by intrathecal (intraspinal) drug delivery: report of an interdisciplinary expert panel

INTRODUCTION

The use of intrathecal (IT) infusion of analgesic medications to treat patients with chronic refractory pain has increased since its inception in the 1980s, and the need for clinical research in IT therapy is ongoing. The Polyanalgesic Consensus Conference (PACC) panel of experts convened in 2000, 2003, and 2007 to make recommendations on the rational use of IT analgesics based on preclinical and clinical literature and clinical experiences.

METHODS

The PACC panel convened again in 2011 to update the standard of care for IT therapies to reflect current knowledge gleaned from literature and clinical experience. A thorough literature search was performed, and information from this search was provided to panel members. Analysis of published literature was coupled with the clinical experience of panel members to form recommendations regarding the use of IT analgesics to treat chronic pain.

RESULTS

After a review of literature published from 2007 to 2011 and discussions of clinical experience, the panel created updated algorithms for the rational use of IT medications for the treatment of neuropathic pain and nociceptive pain.

CONCLUSIONS

The advent of new algorithmic tracks for neuropathic and nociceptive pain is an important step in improving patient care. The panel encourages continued research and development, including the development of new drugs, devices, and safety recommendations to improve the care of patients with chronic pain.

Safety and efficacy of intrathecal drug delivery for pain

SUMMARY The practice of delivering analgesic drugs into the intrathecal space has evolved over the past several decades from a ‘last-ditch’ therapy for intractable pain in patients with terminal cancer to a more widely applied strategy for treating patients with chronic nonmalignant pain as well. This review discusses the available safety and efficacy data of intrathecal drug delivery with a focus on device- and user-related safety issues.