Physicochemical Stability Study of the Morphine-Bupivacaine-Ziconotide Association.

OBJECTIVE: The aim of this study was to investigate the physicochemical stability of morphine-bupivacaine-ziconotide mixtures used in intrathecal analgesia in polypropylene syringes and intrathecal pumps. MATERIALS AND METHODS: The stability study method was conceived according to International Council for Harmonisation guidelines. For propylene syringes, six different mixtures of morphine-bupivacaine and ziconotide were assessed over seven days. Two storage temperatures were tested (5 °C ± 3 °C and 25 °C ± 2 °C). For implantable pumps, nine different mixtures were assessed over 60 days and stored at 37 °C. Assays were performed using ultrahigh-pressure liquid chromatography. Turbidity and pH also were measured throughout the study. RESULTS: Results confirmed excellent physicochemical stability for morphine and bupivacaine in the study for all conditions investigated (pumps at 37 °C, polypropylene syringes at 5 °C ± 3 °C and 25 °C ± 2 °C). Concerning ziconotide, after seven days, our study showed that every 95% confidence interval calculated had lower bounds >90% for all mixtures stored in polypropylene syringes. In implantable pumps, a decrease of the concentration was observed in all the mixtures studied. Moreover, the appearance of a degradation product confirmed the ziconotide degradation. CONCLUSION: All results are in favor with a physicochemical stable preparation for six mixture profiles when stored in polypropylene syringes at 5 °C ± 3 °C and 25 °C ± 2 °C. For mixtures stored in implantable pumps, the efficacy should decrease over time owing to the degradation of ziconotide. A trade-off between high morphine concentration and increased refill interval will need to be found by clinicians.

The Polyanalgesic Consensus Conference (PACC)®: Intrathecal Drug Delivery Guidance on Safety and Therapy Optimization When Treating Chronic Noncancer Pain.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians and scientists based on expertise with international representation to establish evidence-based guidance on intrathecal drug delivery in treating chronic pain. This Polyanalgesic Consensus Conference (PACC)® project, created more than two decades ago, intends to provide evidence-based guidance for important safety and efficacy issues surrounding intrathecal drug delivery and its impact on the practice of neuromodulation. MATERIALS AND METHODS: Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when PACC® last published guidelines) to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence is scant. RESULTS: The PACC® examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The PACC® recommends best practices regarding intrathecal drug delivery to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

Postoperative prophylactic intermittent noninvasive ventilation versus usual postoperative care for patients at high risk of pulmonary complications: a multicentre randomised trial.

BACKGROUND: Pulmonary complications are an important cause of morbidity and mortality after surgery. We evaluated the clinical effectiveness of noninvasive ventilation (NIV) in preventing postoperative acute respiratory failure. METHODS: This is an open, multicentre randomised trial that included patients at high risk of postoperative pulmonary complications after elective or semi-urgent surgery with an Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score ≥45. Patients were randomly assigned to intermittent prophylactic face-mask NIV for 6-8 h day-1 or usual postoperative care. The primary outcome was in-hospital acute respiratory failure within 7 days after surgery. Patients who underwent surgery and postoperative extubation were included in the modified intended-to-treat analysis. Results are presented as n (%) and odds ratios (ORs) with 95% confidence intervals. RESULTS: Between November 2017 and October 2019, 266 patients were randomised and 253 included in the main analysis. Of these, 203 (80.2%) were male with a mean age of 68 (11) yr and an ARISCAT score of 53 (6); 237 subjects (93.7%) underwent cardiac or thoracic surgery. There were 125 patients allocated to prophylactic NIV and 128 to usual care. Unplanned treatment termination occurred in 58 subjects in the NIV group, which was linked to NIV discomfort for 36 subjects. There was no difference in the incidence of the primary outcome of postoperative acute respiratory failure between treatment groups (NIV: 30 of 125 subjects [24.0%] vs usual care: 35 of 128 subjects [27.3%]; OR 0.97 [0.90-1.04]; P=0.54). CONCLUSIONS: Prophylactic NIV was difficult to implement after high-risk surgery because of low patient compliance. Prophylactic NIV did not prevent acute respiratory failure. CLINICAL TRIAL REGISTRATION: NCT03629431 and EudraCT 2017-001011-36.

Management of Cancer-Related Pain With Intrathecal Drug Delivery: A Systematic Review and Meta-Analysis of Clinical Studies.

BACKGROUND: Despite increased attention paid to assessment and management, pain continues to be a prevalent and undertreated symptom in patients with cancer. Intrathecal drug delivery (IDD) is a therapeutic option that allows targeted delivery of analgesics to the intrathecal space. OBJECTIVE: The aim of this review was to examine the efficacy of managing cancer-related pain with IDD. Secondary objectives included the effects of IDD on systemic opioid use and infection rates. EVIDENCE REVIEW: A systematic search of the literature published between 1990 and 2019 was performed to identify studies evaluating the efficacy and/or safety of IDD with external or implanted pumps in patients with cancer-related pain. Data were extracted and meta-analyses performed to determine the mean changes in pain levels at short-, mid-, and long-term intervals; changes in opioid (oral morphine equivalent [OME]) daily dose; and infection rates. Changes were assessed compared with baseline. FINDINGS: Pain levels were decreased from baseline: On a 0 to 10 scale, mean differences were -4.34 (95% CI [-4.93 to -3.75], p < 0.001) at 4 to 5 weeks; -4.34 (95% CI [-5.07 to -3.62], p < 0.001) at 6 to 12 weeks; and -3.32 (95% CI [-4.60 to -2.04], p < 0.001) at >6 months. Weighted mean OME consumption was reduced by 308.24 (SE = 22.72) mg/d. Weighted mean infection rates were ∼3% for external and implanted pumps. CONCLUSIONS: Meta-analyses show a statistically significant and sustained decrease in cancer pain with IDD, compared with baseline. Systemic opioid consumption was reduced on average by >50% after IDD. Infection rates were comparable with other indications.

Effectiveness and Safety of Intrathecal Drug Delivery Systems for the Management of Cancer Pain: A Systematic Review and Meta-Analysis.

OBJECTIVES: Intrathecal drug delivery systems (IDDS) and spinal cord stimulation (SCS) have been proposed and assessed for the management of cancer pain; however, such treatments remain underused. We conducted a systematic review to evaluate the effectiveness and safety of IDDS and SCS for cancer pain. MATERIALS AND METHODS: Electronic databases MEDLINE, CENTRAL, EMBASE, and WikiStim were searched from 1988 to March 2021. Randomized controlled trials and observational studies of adults with pain related to cancer or its treatment who received an implantable IDDS or SCS were eligible for inclusion. The primary outcome of the review was change in pain intensity from baseline to the last available follow-up, measured using a visual analog scale or numerical rating scale. The protocol for this review is registered on PROSPERO (CRD42021240717). RESULTS: A total of 22 studies (24 reports) included a total of 3043 participants who received either IDDS or SCS for cancer pain. Eight studies reporting data for 405 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction at the latest posttreatment follow-up time compared with baseline (mean difference [MD], -3.31; 95% CI, -4.18 to -2.45; p < 0.001). Six studies reporting data for 325 participants with an IDDS could be included in the meta-analysis of pain intensity that showed a statistically significant reduction up to one month after treatment compared with baseline (MD, -3.53; 95% CI, -4.06 to -3.00; p < 0.001). A meta-analysis including studies of participants with either an IDDS or an SCS device showed similar results. Improvements in other outcomes following implantation of IDDS also were observed. Postdural puncture headache was the most reported complication, whereas urinary retention, nausea, and vomiting were commonly reported side effects. CONCLUSION: Our findings suggest that IDDS is effective in reducing pain intensity for patients with cancer pain when compared with pretreatment.

Physicochemical Stability Study of the Morphine-Ropivacaine-Ziconotide Association in Implantable Pumps for Intrathecal Administration.

PURPOSE: This study aimed to investigate the physicochemical stability of morphine-ropivacaine-ziconotide mixtures used in intrathecal analgesia. MATERIALS AND METHODS: Eight mixtures were studied to assess their stability profiles according to the initial drug concentrations used. The solutions obtained were put in implantable pumps and stored at 37 °C over a period of 60 days. Assays were performed using ultra high-pressure liquid chromatography. Turbidity and pH were also measured throughout the study. RESULTS: Results confirmed excellent physicochemical stability for morphine and ropivacaine. Concerning ziconotide, three of the eight mixtures did not show any sign of chemical instability: average concentrations remained constant throughout the 60 days. A decrease of the concentration was observed for the five other mixtures. Moreover, the appearance of a degradation product linked to oxidation confirmed the ziconotide degradation. CONCLUSIONS: All these results are in favor of a physicochemical stable preparation for three of the mixture profiles when stored in implantable pumps at 37 °C up to 60 days. For the five others, the efficacy should decrease over time owing to the degradation of ziconotide. The decrease in kinetics of the ziconotide concentration depends on the mixing profile. One possibility is to adapt the filling intervals according to the profile of the mixture. Finally, the results show the period of stability ensuring maximum analgesic efficacy for the eight mixture profiles studied.

Ziconotide for the Management of Cancer Pain: A Budget Impact Analysis.

OBJECTIVES: Recent recommendations on starting dose, smaller dose increments, and longer intervals between dose increase have the potential to increase the safety of ziconotide administration in addition to improving its value for money. Ziconotide is not routinely commissioned in England, with one of the concerns being whether it represents the best use of resources. The aim of this project is to conduct a budget impact analysis to estimate the costs or savings associated with the changes in ziconotide dosage in addition to its use in combination with morphine for the management of cancer pain. MATERIALS AND METHODS: An open, Markov-like cohort decision analytic model was developed to estimate the budget impact of ziconotide in combination with morphine (ziconotide combination therapy) vs morphine monotherapy through intrathecal drug delivery (ITDD) for the management of cancer pain. The perspective adopted was that of the UK National Health Service, with a five-year time horizon. Sensitivity analyses were conducted to evaluate different scenarios. RESULTS: Ziconotide combination therapy was more expensive than treatment with morphine monotherapy. The total costs of ziconotide combination therapy and morphine monotherapy for the first year were £395,748 and £136,628 respectively. The estimated five-year cumulative budget impact of treatment with ziconotide combination therapy for the five-year time horizon was £2,487,539, whereas that of morphine monotherapy was £913,804. The additional costs in any of the first five years are below the resource impact significance level of £1 million for medical technologies in England. CONCLUSIONS: The results of this budget impact analysis suggest that although a combination of intrathecal ziconotide in combination with morphine is associated with higher costs to the health care system in England, the incremental costs are not significant. Routine commissioning of ziconotide alone or in combination with morphine would provide an alternative for a population with limited ITDD treatment options.

Stability of Morphine Sulfate-Clonidine and Sufentanil-Clonidine Mixtures.

BACKGROUND: Spinal analgesia is recommended for intractable cancer pain. Morphine-clonidine and sufentanil-clonidine are often used in association in intrathecal drug delivery systems, injected by intraabdominal pumps. To refill these pumps and to limit patient transport, it may be necessary to ship the mixtures in polypropylene syringes to peripheral establishments located near patient homes. The purpose of this study is to determine the stability of morphine-clonidine and sufentanil-clonidine mixtures in polypropylene syringes to ensure the best and safest transport conditions and in implantable pumps for intrathecal use. MATERIALS AND METHODS: The stability study method was conceived according to the International Council for Harmonization guidelines. For polypropylene syringes, four different mixtures of morphine-clonidine and sufentanil-clonidine were assessed over seven days. Two storage temperatures were tested (5 ± 3 °C and 25 ± 2 °C). For implantable pumps, two different mixtures of morphine-clonidine and sufentanil-clonidine were assessed over 28 days and stored at 37 °C. RESULTS: For the morphine-clonidine mixtures in polypropylene syringes, all mixtures remained stable for five days in both storage conditions (5 ± 3 °C and 25 ± 2 °C) because of relative concentrations systematically positioned between 90% and 110% (95% CIs of the mean of three samples). The two mixtures in implantable pumps remained stable for 28 days. For the sufentanil-clonidine mixtures in polypropylene syringes, cold conservation kept all the preparations stable for seven days, whereas a quick degradation was observed after only two days for ambient storage conditions. This result is similar to that with an implantable pump, in which the concentration is <90% on day 7 for low concentration mixtures. No visual modification, no significant pH modification, and no changes in turbidity assays were observed in either study. CONCLUSION: This study shows the stability of the morphine-clonidine mixtures in syringes stored at 5 °C for five days and in implantable pumps stored at 37 °C for 28 days. For the sufentanil-clonidine mixtures, the results show stability in syringes for seven days at 5 °C. Pump results show stability of seven days for low concentrations and 28 days for high concentrations.

Diagnosis, management and impact on patients' lives of cancer-related neuropathic pain (CRNP): A European survey.

OBJECTIVE: This study assessed the impact of cancer-related neuropathic pain (CRNP) on patients and the importance of the patient-healthcare professional (HCP) relationship in diagnosis and management. METHODS: A quantitative online survey was conducted involving adult patients from 13 European countries who had been diagnosed with treatable cancer and experienced symptoms of peripheral neuropathy. RESULTS: Of 24,733 screened respondents, 549 eligible persons met the inclusion criteria and completed the questionnaire. Among individuals still experiencing pain, 75% rated it as 'severe' or 'moderate'. In addition, 61% reported a negative impact on day-to-day activities, and 30% said they had stopped working as a result. A third of respondents had received no diagnosis of CRNP despite reporting painful symptoms to an HCP. HCPs spending enough time discussing pain and understanding the impact on patients' lives were each associated with an increased likelihood of a formal CRNP diagnosis. Compared with individuals currently in active cancer treatment, cancer survivors were less likely to have a diagnosis of CRNP or regular pain conversations with HCPs. CONCLUSION: CRNP remains under-recognised despite its substantial impact on patients' lives. Clinical practice may be improved by strengthening patient-HCP relationships around pain discussions and increasing the focus on pain management among cancer survivors.

Cancer Pain Management-A European Perspective.

Cancer pain management is a major challenge in both Europe and the United States. Recent studies show that the incidence of cancer pain remains high and even increases at an advanced stage of the disease.

Intrathecal Analgesia in Cancer Pain.

The number of new cancer cases has been increasing globally over the last several decades.

Stability Study of Admixtures Combining Ziconotide With Morphine or Sufentanil in Polypropylene Syringes.

BACKGROUND: The association of morphine ziconotide or sufentanil ziconotide was used to manage cancer pain. Moving these patients is sometimes difficult. In order to transport these syringes for pump refilling, it could be interesting to demonstrate the stability of the mixture and so to be able to ensure the best transport conditions of syringes. MATERIALS AND METHODS: A stability indicating UPLC-DAD method was developed and validated according to the ICH guidelines. Fur mixtures of each association have been stored in 5 ± 3°C and 25 ± 2°C and were evaluated for seven days and compared to the initial observed concentrations. RESULTS: The stability of these associations was demonstrated at 5°C for seven days thanks to relative concentrations (95% confidence intervals of the mean of three samples) systematically positioned between 95% and 105%. No degradation product was observed during the stability study. CONCLUSION: This study shows the stability of these association morphine ziconotide or sufentanil ziconotide at 5°C for seven days in polypropylen syringes. This result will allow the transport of the preparation under optimal conditions. Advance preparations for intrathecal pump refills could also be feasible.

First Evaluation Switching From Ropivacaine to Highly Concentrated Bupivacaine in Intrathecal Mixtures for Cancer Pain.

BACKGROUND: Intrathecal drug delivery is widely used for intractable cancer pain treatment. A combination of drugs with morphine and bupivacaine is recommended in first line therapy. In France, we use ropivacaine 10 mg/mL instead of bupivacaine 5 mg/mL, the only concentration available. Bupivacaine 40 mg/mL has been available in France only since July 2020 under temporary authorization of use. OBJECTIVES: The main objective of the study was to evaluate the safety, efficacy by pain assessment, to analyze drug dosage changes, to report adverse events (AEs) and conversion ratios switching from ropivacaine to bupivacaine. Secondary objective was to evaluate costs differences. MATERIALS AND METHODS: We conducted this retrospective follow-up monocentric study within the Institut de Cancérologie de l'Ouest (ICO) Pain Department in Angers, France. We included 14 patients aged 18 years and above, implanted with an Intrathecal Drug Delivery Systems (IDDS) for cancer pain treatment and followed up at ICO from July 2020 to February 2021 after switching from ropivacaine to bupivacaine. We used a continuous infusion mode and Bolus could be added through Personal Therapy Manager (PTM). RESULTS: The median conversion ratio between ropivacaine and bupivacaine was 0.68 (0.65; 0.69) and resulted in no significant change in numeric rating scale evaluation (p = 0.10). We observed moderate and rapidly reversible AEs such as clinical hypotension (29%) and motor block after bolus (21%). The estimated median hospital cost per day was significantly lower (p = 0.05) for the bupivacaine refills than for the last ropivacaine pump refill, decreasing from US$ 61.7 (49.6; 70.5) to US$ 50.4 (45.9; 60.4). The median reimbursement per day from the National Health Insurance (NHI) was three times lower for bupivacaine pump refill when compared to the last ropivacaine pump refill (p < 0.01), decreasing from US$ 179.10 (156.79; 182.91) to US$ 64.59 (59.85; 71.89). CONCLUSION: Switching from ropivacaine to bupivacaine in IDDS appears more efficacious while remaining just as secure, and at lower cost.

Study of Physicochemical Stability of Ziconotide in Medication Cassette Reservoir.

OBJECTIVE: To determine the physicochemical stability of ziconotide solutions for intrathecal administration in the Medication Cassette Reservoir (MCR). MATERIALS AND METHODS: A stability indicating UPLC-DAD method was developed and validated according to the ICH guidelines. Two mixtures of ziconotide (0.40 µg/mL and 0.60 µg/mL) stored in MCR stored at 25 ± 2°C were evaluated for 14 days and compared to the initial observed concentrations. RESULTS: The physicochemical stability of the two solutions was demonstrated for two days thanks to relative concentrations, pH measurement, visual inspections, and turbidity assays. A degradation product was observed and increased during the study. CONCLUSION: This study showed a very low physicochemical stability of diluted ziconotide stored at 25 ± 2°C in the MCR. The intrathecal administration of ziconotide does not seem appropriate with this device for outpatients.

Optimizing Initial Intrathecal Drug Ratio for Refractory Cancer-Related Pain for Early Pain Relief. A Retrospective Monocentric Study.

OBJECTIVE: Intrathecal (IT) drug delivery has shown its efficiency in treating refractory cancer pain, but switching opioids from the systemic to the intrathecal route is a challenging phase. Moreover, associations are widely used and recommended. Few data deal with the initial dosage of each drug. Analyzing conversion factors and initial dosages used in intrathecal therapy seems essential to decreasing the length of titration and to delivering quick pain relief to patients. METHODS: We retrospectively analyzed data from consecutive adult patients implanted with an intrathecal device for cancer pain and treated at the Institut de Cancérologie de l'Ouest, in Angers, France, for four years. The main goal was to identify factors associated with early pain relief after intrathecal drug delivery system (IDDS) implantation. RESULTS: Of the 220 IDDS-treated patients, 70 (32%) experienced early pain relief (EaPR) and 150 (68%) delayed pain relief (DePR). Performance Status stage and initial IT ropivacaine:IT morphine ratio were the variables independently associated with EaPR. The best IT ropivacaine:IT morphine ratio to predict EaPR was 5:1, with a 73% (95% confidence interval [CI] = 64.8% to 79.6%) sensitivity and a 67.1% (95% CI = 54.9% to 77.9%) specificity. EaPR subjects experienced better pain relief (-84% vs -60% from baseline pain score, P < 0.0001), shorter length of hospitalization (7 vs 10 days, P < 0.0001), and longer survival (155 vs 82 days, P = 0.004). CONCLUSIONS: Local anesthetic:morphine ratio should be considered when starting IDDS treatment. EaPR during the IT analgesia titration phase was associated with better pain relief and outcomes in patients with refractory cancer-related pain.

Intrathecal Drug Delivery Systems for Refractory Pancreatic Cancer Pain: Observational Follow-up Study Over an 11-Year Period in a Comprehensive Cancer Center.

BACKGROUND: Pancreatic cancer is the fourth leading cause of cancer-related death in Europe and the United States. Studies have demonstrated that patients with pancreatic cancer have a high prevalence of pain, with rates varying from 47% to 82%. Analgesia using intrathecal drug delivery systems (IDDS) has been poorly studied specifically in this population. METHODS: The IDDS for pancreatic cancer pain was a follow-up observational study designed to evaluate 11-year results of IDDS for refractory pancreatic cancer pain at the Institut de Cancérologie de L'Ouest, Paul Papin in France. Patients were followed from March 2006 to April 2017. Patients were selected for IDDS based on multidisciplinary meeting discussion. All IDDS-treated patients were prescribed a combined intrathecal analgesics regimen through a catheter placed according to painful metameric level. Postimplant assessment of pain was determined using a numerical rating scale (NRS). Patients were followed via day-hospital visits and telephone calls at least monthly until death. Pain scores were compared using the Wilcoxon signed rank test. Overall survival (OS) was estimated using the Kaplan-Meier method and compared between groups by log rank tests. RESULTS: Ninety-three patients received IDDS, and total therapy duration accounts for 10,300 IDDS days. Implanted patients suffered from severe pain before implantation (median presurgical NRS, 8 [interquartile range, 7-9]) despite a median 360 mg (260-600) oral morphine equivalent daily dose. Median OS in the whole cohort after intrathecal treatment start was 82 days (95% confidence interval, 59-95). Median OS after surgery for implantable pump was 91 days (83-111) and for external pump 27 days (20-49; P < .0001). IDDS was associated with pain relief with a significant statistical difference between preimplantation NRS pain score and 1 week (median, -6 [-7 to -4]; P < .001), 1 month (median, -5 [-6 to -3]; P < .001), and 3 months (median, -6 [-7 to -4]; P < .001). Severe pain (NRS score, ≥7) decreased from 89.2% before surgery to 4.5% after 1 week, 6.7% after 1 month, and 10.3% after 3 months of IDDS implant (P < .01). Global complications rate was low, consistent with published literature. CONCLUSIONS: Despite our study's limitations, results suggest that long-term IDDS for refractory malignant pain due to pancreatic cancer was both efficacious and safe in pancreatic cancer pain. We have demonstrated, in the largest series of IDDS for pancreatic cancer pain reported yet, a clinically and statistically significant pain reduction in patients receiving IDDS.

In vitro stability of low-concentration ziconotide alone or in admixtures in intrathecal pumps.

OBJECTIVES: Ziconotide is often administered in combination with other analgesics via an intrathecal pump. Studies have established that ziconotide is stable when delivered alone in high concentrations. No stability data are available, however, for ziconotide given in low concentrations and/or with other analgesics as usually occurs in clinical oncology practice. The objective of this study was to assess the in vitro stability of ziconotide alone and combined with other analgesics in intrathecal pumps at 37 °C, as well as in syringes at 5 °C, to evaluate conditions for storing and transporting preparations. MATERIALS AND METHODS: Various ziconotide concentrations (0.1, 0.25, 0.5, and 0.75 µg/mL) were combined with an admixture of ropivacaine (7.5 mg/mL), morphine (7.5 mg/mL), and clonidine (15 µg/mL) in 20-mL intrathecal pumps at 37 °C and in syringes at 5 °C. Solutions of ziconotide alone in concentrations of 0.25, 0.5, 0.75, and 1 µg/mL were introduced into pumps at 37 °C and syringes at 5 °C. Assays were performed using ultra high pressure liquid chromatography. RESULTS: In admixtures, mean ziconotide concentrations decreased linearly to 53.4% (± 3.33%) of baseline after 35 days. When ziconotide was introduced alone in pumps at 37 °C, the residual concentration on day 31 was 35.54% (± 0.04%) with 0.25 µg/mL, 39.37% (± 0.15%) with 0.5 µg/mL, and 44.49% (± 0.18%) with 1 µg/mL. Ziconotide alone or combined with the other analgesics was stable in syringes stored at 5 °C. The preparations complied with the prescriptions, with a mean error of less than 10%, except with the lowest ziconotide concentration (0.1 µg/mL). CONCLUSIONS: At the low ziconotide concentrations studied, the degradation of ziconotide admixed with other drugs was linear and only weakly influenced by the baseline concentration. Linear regression with intrapolation to 30 days showed that the degradation of ziconotide admixed with other drugs was consistent with previously published data.

Controversies in intrathecal drug delivery for cancer pain.

Pain and suffering related to cancer are challenging issues that continue to deserve consideration for treatment optimization. Advances in analgesic management and control of the underlying cancer have improved symptom management, yet many patients still suffer from uncontrolled pain. Intrathecal drug delivery has an established role in the management of refractory cancer pain, but there are significant knowledge gaps in our understanding and application of this therapy. This review addresses several areas of controversy, including the importance of intrathecal catheter tip location, the necessity of an intrathecal trial and the role of intrathecal ziconotide and local anesthetics. In each area, the evidence is discussed, with an emphasis on presenting practical clinical guidance and highlighting deficiencies in our knowledge that are worthy of future investigation.