Phase III evaluation of nortriptyline for alleviation of symptoms of cis-platinum-induced peripheral neuropathy

Effect of Vitis vinifera hydroalcoholic extract against oxaliplatin neurotoxicity: in vitro and in vivo evidence

Oxaliplatin treatment is associated with the development of a dose-limiting painful neuropathy impairing patient's quality of life. Since oxidative unbalance is a relevant mechanism of oxaliplatin neurotoxicity, we assessed the potential antioxidant properties of Vitis vinifera extract in reducing oxaliplatin-induced neuropathy as a valuable therapeutic opportunity. A hydroalcoholic extract of Vitis vinifera red leaf was characterized and tested in primary rat astrocyte cells treated with oxaliplatin (100 μM). Oxaliplatin lethality in the human adenocarcinoma cell line HT-29 was evaluated in the absence and presence of the extract. In vivo, pain hypersensitivity was measured in a rat model of neuropathy induced by oxaliplatin and ex vivo molecular targets of redox balance were studied. Vitis vinifera extract (50 μg mL^-1, 4 h incubation) significantly reduced the oxaliplatin-dependent superoxide anion increase and lipid peroxidation in rat astrocytes but did not interfere with the mortality elicited by oxaliplatin in HT-29 cancer cells. In oxaliplatin-treated rats, a repeated daily administration of the Vitis vinifera extract (300 mg kg^-1, p.o.) significantly prevented mechanical and thermal hypersensitivity to noxious and non noxious stimuli. mRNA and protein levels of Nrf2 were normalized in spinal cord and DRGs. Moreover, in the spinal cord, the extract significantly decreased the activation of astrocytes. Vitis vinifera reduced oxidative damages and relieved pain without influencing oxaliplatin anti-cancer activity.

Synthetic peripherally-restricted cannabinoid suppresses chemotherapy-induced peripheral neuropathy pain symptoms by CB1 receptor activation

Chemotherapy-induced peripheral neuropathy (CIPN) is a severe and dose-limiting side effect of cancer treatment that affects millions of cancer survivors throughout the world and current treatment options are extremely limited by their side effects. Cannabinoids are highly effective in suppressing pain symptoms of chemotherapy-induced and other peripheral neuropathies but their widespread use is limited by central nervous system (CNS)-mediated side effects. Here, we tested one compound from a series of recently developed synthetic peripherally restricted cannabinoids (PRCBs) in a rat model of cisplatin-induced peripheral neuropathy. Results show that local or systemic administration of 4-{2-[-(1E)-1[(4-propylnaphthalen-1-yl)methylidene]-1H-inden-3-yl]ethyl}morpholine (PrNMI) dose-dependently suppressed CIPN mechanical and cold allodynia. Orally administered PrNMI also dose-dependently suppressed CIPN allodynia symptoms in both male and female rats without any CNS side effects. Co-administration with selective cannabinoid receptor subtype blockers revealed that PrNMI's anti-allodynic effects are mediated by CB1 receptor (CB1R) activation. Expression of CB2Rs was reduced in dorsal root ganglia from CIPN rats, whereas expression of CB1Rs and various endocannabinoid synthesizing and metabolizing enzymes was unaffected. Daily PrNMI treatment of CIPN rats for two weeks showed a lack of appreciable tolerance to PrNMI's anti-allodynic effects. In an operant task which reflects cerebral processing of pain, PrNMI also dose-dependently suppressed CIPN pain behaviors. Our results demonstrate that PRCBs exemplified by PrNMI may represent a viable option for the treatment of CIPN pain symptoms.

Scrambler therapy efficacy and safety for neuropathic pain correlated with chemotherapy-induced peripheral neuropathy in adolescents: A preliminary study

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of chemotherapy, in need of effective treatment. Preliminary data support the efficacy of scrambler therapy (ST), a noninvasive cutaneous electrostimulation device, in adults with CIPN. We test the efficacy, safety, and durability of ST for neuropathic pain in adolescents with CIPN.

PATIENTS AND METHODS

We studied nine pediatric patients with cancer and CIPN who received ST for pain control. Each patient received 45-min daily sessions for 10 consecutive days as a first step, but some of them required additional treatment.

RESULTS

Pain significantly improved comparing Numeric Rate Scale after 10 days of ST (9.22 ± 0.83 vs. 2.33 ± 2.34; P < 0.001) and at the end of the optimized cycle (EOC) (9.22 ± 0.83 vs. 0.11 ± 0.33, P < 0.001). The improvement in quality of life was significantly reached on pain interference with general activity (8.67 ± 1.66 vs. 3.33 ± 2.12, P < 0.0001), mood (8.33 ± 3.32 vs. 2.78 ± 2.82, P < 0.0005), walking ability (10.00 vs. 2.78 ± 1.22, P < 0.0001), sleep (7.56 ± 2.24 vs. 2.67 ± 1.41, P < 0.001), and relations with people (7.89 ± 2.03 vs. 2.11 ± 2.03, P < 0.0002; Lansky score 26.7 ± 13.2 vs. 10 days of ST 57.8 ± 13.9, P < 0.001; 26.7 ± 13.2 vs. EOC 71.1 ± 16.2, P < 0.001).

CONCLUSION

Based on these preliminary data, ST could be a good choice for adolescents with CIPN for whom pain control is difficult. ST caused total relief or dramatic reduction in CIPN pain and an improvement in quality of life, durable in follow-up. It caused no detected side effects, and can be retrained successfully. Further larger studies should be performed to confirm our promising preliminary data in pediatric patients with cancer.

High-Intensity Ultrasound Treatment for Vincristine-Induced Neuropathic Pain

BACKGROUND

Vincristine is a commonly used chemotherapeutic agent that results in debilitating untreatable peripheral neuropathy.

OBJECTIVE

To determine the effects of pulsed high-intensity focused ultrasound (HIFU) on sensory thresholds in a validated vincristine-induced neuropathy (VIN) rodent model.

METHODS

VIN was induced and mechanical allodynia was confirmed by nociceptive testing. von Frey fibers and Randall-Sellito test were used as measures of innocuous and noxious mechanical thresholds, respectively, and the hot plate test for thermal thresholds. Tests were performed before VIN, after 2 wk of vincristine, at 24, 48, 72, and 120 h after HIFU applied to the left L5 dorsal root ganglia at 3 Watts for 3 min. Comparisons were made between a VIN cohort who underwent HIFU, a VIN cohort who underwent sham HIFU, and naïve rodents who underwent HIFU.

RESULTS

VIN HIFU rats had significantly increased mechanical thresholds at 24 h (P &lt; .001), 48 h (P = .008), 72 h (P = .003), and 120 h (P = .03) after treatment, when compared to pre-HIFU thresholds. Furthermore, at 24 and 48 h following treatment, VIN HIFU rats had significantly higher innocuous and noxious mechanical thresholds and thermal thresholds than VIN sham HIFU rats (P &lt; .001). Thresholds were not altered in naïve rodents who underwent HIFU. Histological data of L5 dorsal root ganglia of VIN HIFU rats suggest that transient cellular edema resolves by 48 h.

CONCLUSION

Our data suggest that HIFU increases mechanical and thermal thresholds in VIN rodents. Whether HIFU can preclude the development of reduced thresholds in the VIN model warrants further study.

Pain in Platin-Induced Neuropathies: A Systematic Review and Meta-Analysis

Introduction

Platin-induced peripheral neuropathy (PIPN) is a common cause of PN in cancer patients. The aim of this paper is to systematically review the current literature regarding PIPN, with a particular focus on epidemiological and clinical characteristics of painful PIPN, and to discuss relevant management strategies.

Methods

A systematic computer-based literature search was conducted on the PubMed database.

Results

This search strategy resulted in the identification of 353 articles. After the eligibility assessment, 282 articles were excluded. An additional 24 papers were identified by scanning the reference lists. In total, 95 papers met the inclusion criteria and were used for this review. The prevalence of neuropathic symptoms due to acute toxicity of oxaliplatin was estimated at 84.6%, whereas PN established after chemotherapy with platins was estimated at 74.9%. Specifically regarding pain, the reported prevalence of pain due to acute toxicity of oxaliplatin was estimated at 55.6%, whereas the reported prevalence of chronic peripheral neuropathic pain in PIPN was estimated at 49.2%.

Conclusion

Peripheral neuropathy is a common complication in patients receiving platins and can be particularly painful. There is significant heterogeneity among studies regarding the method for diagnosing peripheral neuropathy. Nerve conduction studies are the gold standard and should be performed in patients receiving platins and complaining of neuropathic symptoms post-treatment.

Future cancer research priorities in the USA: a Lancet Oncology Commission

We are in the midst of a technological revolution that is providing new insights into human biology and cancer. In this era of big data, we are amassing large amounts of information that is transforming how we approach cancer treatment and prevention. Enactment of the Cancer Moonshot within the 21st Century Cures Act in the USA arrived at a propitious moment in the advancement of knowledge, providing nearly US$2 billion of funding for cancer research and precision medicine. In 2016, the Blue Ribbon Panel (BRP) set out a roadmap of recommendations designed to exploit new advances in cancer diagnosis, prevention, and treatment. Those recommendations provided a high-level view of how to accelerate the conversion of new scientific discoveries into effective treatments and prevention for cancer. The US National Cancer Institute is already implementing some of those recommendations. As experts in the priority areas identified by the BRP, we bolster those recommendations to implement this important scientific roadmap. In this Commission, we examine the BRP recommendations in greater detail and expand the discussion to include additional priority areas, including surgical oncology, radiation oncology, imaging, health systems and health disparities, regulation and financing, population science, and oncopolicy. We prioritise areas of research in the USA that we believe would accelerate efforts to benefit patients with cancer. Finally, we hope the recommendations in this report will facilitate new international collaborations to further enhance global efforts in cancer control.

Risk-reduction and treatment of chemotherapy-induced peripheral neuropathy

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN), a common adverse effect of several chemotherapeutic agents, has a significant impact on quality of life and may even compromise treatment efficacy, requiring chemotherapy dose reduction or discontinuation. CIPN is predominantly related with sensory rather than motor symptoms and the most common related cytotoxic agents are platinum compounds, taxanes and vinca alkaloids. CIPN symptoms may resolve after treatment cessation, but they can also be permanent and continue for years. Areas covered: We present an overview of CIPN pathophysiology, clinical assessment, prevention and treatment identified through a Pubmed search. Expert commentary: No substantial progress has been made in the last few years within the field of prevention and/or treatment of CIPN, in spite of remarkable efforts. Continuous research could expand our knowledge about chemotherapeutic-specific neuropathic pathways and eventually lead to the conception of innovative and targeted agents for the prevention and/or treatment of this debilitating chemotherapy adverse effect.

Synergistic Interaction Between Dexmedetomidine and Ulinastatin Against Vincristine-Induced Neuropathic Pain in Rats

Antimicrotubulin chemotherapeutic agents such as vincristine (VCR), often induce peripheral neuropathic pain. It is usually permanent and seriously harmful to cancer patients' quality of life and can result in the hampering of clinical treatments. Currently, there is no definitive therapy, and many of the drugs approved for the treatment of other neuropathic pain have shown little or no analgesic effect. It is therefore vital to find new and novel therapeutic strategies for patients suffering from chemotherapeutic agent-induced neuropathic pain to improve patients' quality of life. This study shows that intrathecal injections of dexmedetomidine (DEX), or intraperitoneally administered ulinastatin (UTI) significantly reduces Sprague Dawley rats' mechanical allodynia induced by VCR via upregulation of interleukin-10 expression and activating the α2-adrenergic receptor in dorsal root ganglion (DRG). Moreover, when combined there is a synergistic interaction between DEX and UTI, which acts against VCR-induced neuropathic pain. This synergistic interaction between DEX and UTI may be partly attributed to a common analgesic pathway in which the upregulation of interleukin -10 plays an important role via activating α2-adrenergic receptor in rat dorsal root ganglion. The combined use of DEX and UTI does not affect the rat's blood pressure, heart rate, sedation, motor score, spatial learning, or memory function. All of these show that the combined use of DEX and UTI is an effective method in relieving VCR-induced neuropathic pain in rats.

PERSPECTIVE

This article documents the synergistic interaction between 2 widely used drugs, DEX and UTI, against VCR-induced neuropathic pain. The results provide a potential target and novel drug administrated method for the clinical treatment of chemotherapy-induced peripheral neuropathic pain.

Pain in chemotherapy-induced peripheral neurotoxicity

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a potentially dose-limiting side effect of the treatment of several cancers. CIPN is predominantly or exclusively sensory, and it is frequently associated with unpleasant symptoms, overall referred to as "pain." However, given the markedly different clinical presentation and course of CIPN depending on the antineoplastic drug used, the broad term "pain" in the specific context of CIPN needs to be reconsidered and refined. In fact, a precise identification of the features of CIPN has relevant implication in the design of rational-based clinical trials and in the selection of possible active drugs.

Pathophysiology of Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced neuropathy is a common, dose-dependent adverse effect of several antineoplastics. It can lead to detrimental dose reductions and discontinuation of treatment, and severely affects the quality of life of cancer survivors. Clinically, chemotherapy-induced peripheral neuropathy presents as deficits in sensory, motor, and autonomic function which develop in a glove and stocking distribution due to preferential effects on longer axons. The pathophysiological processes are multi-factorial and involve oxidative stress, apoptotic mechanisms, altered calcium homeostasis, axon degeneration and membrane remodeling as well as immune processes and neuroinflammation. This review focusses on the commonly used antineoplastic substances oxaliplatin, cisplatin, vincristine, docetaxel, and paclitaxel which interfere with the cancer cell cycle-leading to cell death and tumor degradation-and cause severe acute and chronic peripheral neuropathies. We discuss drug mechanism of action and pharmacokinetic disposition relevant to the development of peripheral neuropathy, the epidemiology and clinical presentation of chemotherapy-induced neuropathy, emerging insight into genetic susceptibilities as well as current understanding of the pathophysiology and treatment approaches.

[Chemotherapy-induced peripheral neuropathy and neuropathic pain]

The perception of the media is that chemotherapy is mainly associated with nausea, vomiting and hair loss. In the longer term the development of peripheral neuropathy, i.e. chemotherapy-induced peripheral neuropathy (CIPN) is often more important for patients. The CIPN represents a side effect of many antineoplastic substances with severe functional impairment and its prevention and treatment is an important task. In addition to many interventions, which have been shown to be ineffective, physiotherapeutic measures and possibly the prophylactic application of cold are helpful for prevention. Randomized studies on the treatment of painful CIPN provided positive data for duloxetine and to a lesser extent for venlafaxine.

Incidence of taxane-induced peripheral neuropathy receiving treatment and prescription patterns in patients with breast cancer

PURPOSE

Taxane-induced peripheral neuropathy (TIPN) can affect quality of life and treatment outcomes in breast cancer patients. Despite the high incidence, treatment of PN has not been established. This study aimed to evaluate the incidence, risk factors, and prescribing pattern of TIPN receiving pharmacologic treatment in real-world practice.

METHODS

We conducted a retrospective chart review of 1629 breast cancer patients who received taxanes at the Seoul National University Hospital from July 2012 to June 2014. We determined the incidence and predictors for TIPN treated with anti-neuropathic pain medications during taxane treatment and the 1-year follow-up period after discontinuation of taxanes. The prescribing pattern of anti-neuropathic drugs was also analyzed.

RESULTS

A total of 1516 patients with breast cancer were included, and the incidence of TIPN receiving treatment was 21.9% overall, with 42.2% of patients using paclitaxel and 15.8% using docetaxel. The median time to the first anti-neuropathic pain medication prescribed from the start of taxane treatment was 64 days and was significantly earlier in the paclitaxel group. In 21% of patients, TIPN treatment was started after the end of taxane treatment. Identified risk factors for TIPN were paclitaxel use (vs. docetaxel), old age, overweight, metastatic (vs. non-metastatic) breast cancer, and possibly a 3-weekly taxane schedule (vs. weekly). Gabapentin and pregabalin accounted for 71.7 and 24.3% of total use of anti-neuropathic agents, respectively.

CONCLUSIONS

One-fifth of breast cancer patients who were treated with taxane-based chemotherapy experienced TIPN receiving treatment, and its risk factors were paclitaxel use, old age, overweight, and metastatic cancer.

A randomized exploratory phase 2 study in patients with chemotherapy-related peripheral neuropathy evaluating whole-body vibration training as adjunct to an integrated program including massage, passive mobilization and physical exercises

BACKGROUND

Chemotherapy-induced polyneuropathy (CIPN) is a common toxicity after chemotherapy, immunomodulatory drugs or proteasome inhibitors, which is difficult to treat and may also have impact on quality of life. The objective of the study was to evaluate whole-body vibration (WBV) on the background of an integrated program (IP) including massage, passive mobilization and physical exercises on CIPN.

PATIENTS AND METHODS

In an exploratory phase-2 study patients with CIPN (NCI CTC grade 2/3) were randomized for WBV plus IP (experimental) to IP alone (standard). 15 training sessions within 15 weeks were intended. As primary endpoint we used chair-rising test (CRT) to assess physical fitness and coordination. In addition, locomotor and neurological tests and self-assessment tools were performed.

RESULTS

A total 131 patients with CIPN were randomized (standard, n = 65; experimental, n = 66). The median age was 60 (range 24-71) years; 44 patients had haematological neoplasms and 87 solid tumors. At baseline, all patients presented with an abnormal CRT. Fifteen (standard) and 22 (experimental) patients left the program due to progression/relapse or concomitant disease. There was no significant difference in the proportion of patients with normal CRT (<10 s) at follow up between experimental (68%) and standard (56%) (p = 0.20). All patients experienced less symptoms and pain (p < 0.001) and had improved CRT (p < 0.001) over time. WBV was significantly associated with a higher reduction of time needed for CRT (p = 0.02) and significantly improved warm-detection-threshold comparing baseline to follow-up assessment (p = 0.02).

CONCLUSION

Whole-body vibration on the background of an IP may improve physical fitness and coordination in patients suffering from CIPN. Trial registration Retrospectively registered at http://www.iscrtn.com (ISRCTN 51361937) and http://www.clinicaltrials.gov (NCT02846844).

Agomelatine: a new opportunity to reduce neuropathic pain-preclinical evidence

Antidepressants are first-line treatments of neuropathic pain but not all these drugs are really effective. Agomelatine is an antidepressant with a novel mode of action, acting as an MT1/MT2 melatonergic receptor agonist and a 5-HT2C receptor antagonist that involves indirect norepinephrine release. Melatonin, serotonin, and norepinephrine have been involved in the pathophysiology of neuropathic pain. Yet, no study has been conducted to determine agomelatine effects on neuropathic pain in animal models. Using 3 rat models of neuropathic pain of toxic (oxaliplatin/OXA), metabolic (streptozocin/STZ), and traumatic (sciatic nerve ligation/CCI [chronic constriction nerve injury]) etiologies, we investigated the antihypersensitivity effect of acute and repeated agomelatine administration. We then determined the influence of melatonergic, 5-HT2C, α-2 and β-1/2 adrenergic receptor antagonists in the antihypersensitivity effect of agomelatine. The effect of the combination of agomelatine + gabapentin was evaluated using an isobolographic approach. In STZ and CCI models, single doses of agomelatine significantly and dose dependently reduced mechanical hypersensitivity. After daily administrations for 2 weeks, this effect was confirmed in the CCI model and agomelatine also displayed a marked antihypersensitivity effect in the OXA model. The antihypersensitivity effect of agomelatine involved melatonergic, 5-HT2C, and α-2 adrenergic receptors but not beta adrenoceptors. The isobolographic analysis demonstrated that the combination of agomelatine + gabapentin had additive effects. Agomelatine exerts a clear-cut antihypersensitivity effect in 3 different neuropathic pain models. Its effect is mediated by melatonergic and 5-HT2C receptors and, although agomelatine has no affinity, also by α-2 adrenergic receptors. Finally, agomelatine combined with gabapentin produces an additive antihypersensitivity effect.

Influence of dosing times on cisplatin-induced peripheral neuropathy in rats

BACKGROUND

Although cis-diamminedichloro-platinum (CDDP) exhibits strong therapeutic effects in cancer chemotherapy, its adverse effects such as peripheral neuropathy, nephropathy, and vomiting are dose-limiting factors. Previous studies reported that chronotherapy decreased CDDP-induced nephropathy and vomiting. In the present study, we investigated the influence of dosing times on CDDP-induced peripheral neuropathy in rats.

METHODS

CDDP (4 mg/kg) was administered intravenously at 5:00 or 17:00 every 7 days for 4 weeks to male Sprague-Dawley rats, and saline was given to the control group. To assess the dosing time dependency of peripheral neuropathy, von-Frey test and hot-plate test were performed.

RESULTS

In order to estimate hypoalgesia, the hot-plate test was performed in rats administered CDDP weekly for 4 weeks. On day 28, the withdrawal latency to thermal stimulation was significantly prolonged in the 17:00-treated group than in the control and 5:00-treated groups. When the von-Frey test was performed to assess mechanical allodynia, the withdrawal threshold was significantly lower in the 5:00 and 17:00-treated groups than in the control group on day 6 after the first CDDP dose. The 5:00-treated group maintained allodynia throughout the experiment with the repeated administration of CDDP, whereas the 17:00-treated group deteriorated from allodynia to hypoalgesia.

CONCLUSIONS

It was revealed that the severe of CDDP-induced peripheral neuropathy was inhibited in the 5:00-treated group, whereas CDDP-treated groups exhibited mechanical allodynia. These results suggested that the selection of an optimal dosing time ameliorated CDDP-induced peripheral neuropathy.

Antidepressants and gabapentinoids in neuropathic pain: Mechanistic insights

Neuropathic pain arises as a consequence of a lesion or disease affecting the somatosensory system. It is generally chronic and challenging to treat. The recommended pharmacotherapy for neuropathic pain includes the use of some antidepressants, such as tricyclic antidepressants (TCAs) (amitriptyline…) or serotonin and noradrenaline re-uptake inhibitors (duloxetine…), and/or anticonvulsants such as the gabapentinoids gabapentin or pregabalin. Antidepressant drugs are not acute analgesics but require a chronic treatment to relieve neuropathic pain, which suggests the recruitment of secondary downstream mechanisms as well as long-term molecular and neuronal plasticity. Noradrenaline is a major actor for the action of antidepressant drugs in a neuropathic pain context. Mechanistic hypotheses have implied the recruitment of noradrenergic descending pathways as well as the peripheral recruitment of noradrenaline from sympathetic fibers sprouting into dorsal root ganglia; and importance of both α2 and β2 adrenoceptors have been reported. These monoamine re-uptake inhibitors may also indirectly act as anti-proinflammatory cytokine drugs; and their therapeutic action requires the opioid system, particularly the mu (MOP) and/or delta (DOP) opioid receptors. Gabapentinoids, which target the voltage-dependent calcium channels α2δ-1 subunit, inhibit calcium currents, thus decreasing the excitatory transmitter release and spinal sensitization. Gabapentinoids also activate the descending noradrenergic pain inhibitory system coupled to spinal α2 adrenoceptors. Gabapentinoid treatment may also indirectly impact on neuroimmune actors, like proinflammatory cytokines. These drugs are effective against neuropathic pain both with acute administration at high dose and with repeated administration. This review focuses on mechanistic knowledge concerning chronic antidepressant treatment and gabapentinoid treatment in a neuropathic pain context.

Targeting inflammation as a treatment modality for neuropathic pain in spinal cord injury: a randomized clinical trial

Background

The purpose of the present study was to examine the effectiveness of an anti-inflammatory intervention as a treatment for neuropathic pain following spinal cord injury (SCI).

Methods

This randomized, parallel-group, controlled clinical trial (NCT02099890) examined 20 participants with varying levels and severities of SCI, randomized (3:2) to either a 12-week anti-inflammatory diet, or control group. Outcome measures consisted of self-determined indices of pain as assessed using the neuropathic pain questionnaire (NPQ) and markers of inflammation as assessed by various pro- and anti-inflammatory cytokines, as well as the eicosanoids PGE2 and LTB4.

Results

A significant group × time interaction was found for sensory pain scores (p < 0.01). A Mann-Whitney test revealed that the change scores (3-month baseline) were significantly different between groups for IFN-y (U = 13.0, p = 0.01), IL-1β (U = 14.0, p = 0.01), and IL-2 (U = 12.0, p = 0.01). A Friedman test revealed the treatment group had a significant reduction in IFN-y (x² = 8.67, p = 0.01), IL-1β (x² = 17.78, p < 0.01), IL-6 (x² = 6.17, p < 0.05), while the control group showed no significant change in any inflammatory mediator. A stepwise backward elimination multiple regression analysis showed that the change in sensory neuropathic pain was a function of the change in the proinflammatory cytokines IL-2 and IFN-y, as well as the eicosanoid PGE2 (R = 0.689, R² = 0.474).

Conclusions

Overall, the results of the study demonstrate the efficacy of targeting inflammation as a means of treating neuropathic pain in SCI, with a potential mechanism relating to the reduction in proinflammatory cytokines and PGE2.

Trial registration

ClinicalTrials.gov, NCT02099890

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0625-4) contains supplementary material, which is available to authorized users.

Randomized sham-controlled pilot trial of weekly electro-acupuncture for the prevention of taxane-induced peripheral neuropathy in women with early stage breast cancer

To investigate the effect of electro-acupuncture (EA) as a non-pharmacological intervention to prevent or reduce chemotherapy-induced peripheral neuropathy (CIPN) in breast cancer patients undergoing chemotherapy of taxane. Women with stage I-III breast cancer scheduled to receive taxane therapy were randomized to receive a standardized protocol of 12 true or sham EA (SEA) weekly treatments concurrent with taxane treatment. Subjects completed the Brief Pain Inventory-Short Form (BPI-SF), Functional Assessment of Cancer Therapy-Taxane neurotoxicity subscale (FACT-NTX), and other assessments at baseline and weeks 6, 12, and 16. A total of 180 subjects were screened, 63 enrolled and 48 completed week 16 assessments. Mean age was 50 with 25 % white, 25 % black, and 43 % Hispanic; 52 % had no prior chemotherapy. At week 12, both groups reported an increase in mean BPI-SF worst pain score, but no mean differences were found between groups (SEA 2.8 vs. EA 2.6, P = .86). By week 16, the SEA group returned to baseline, while the EA group continued to worsen (SEA 1.7 vs. EA 3.4, P = .03). The increase in BPI-SF worst pain score was 1.62 points higher in the EA group than in the SEA group at week 16 (P = .04). In a randomized, sham-controlled trial of EA for prevention of taxane-induced CIPN, there were no differences in pain or neuropathy between groups at week 12. Of concern, subjects on EA had a slower recovery than SEA subjects. Future studies should focus on EA for treatment as opposed to prevention of CIPN.

Pregabalin in Chemotherapy Induced Neuropathic Pain

Chemotherapeutic agents belonging to vinca alkaloids, taxanes, and antitubulins produce peripheral neuropathy for which there is no validated treatment. Pregabalin, a gamma-aminobutyric acid analog, is known to inhibit theα2δ subunit of the voltage-gated calcium channel. Earlier studies and case reports have shown pregabalin to be effective in treating neuropathic pain. We present a case series of patients with chemotherapy-induced peripheral neuropathy who were successfully treated with pregabalin with reduction in the hyperalgesia, allodynia, and improvement in the quality of life.

New Insights into Potential Prevention and Management Options for Chemotherapy-Induced Peripheral Neuropathy

OBJECTIVE

Neurological complications such as chemotherapy-induced peripheral neuropathy (CIPN) and neuropathic pain are frequent side effects of neurotoxic chemotherapy agents. An increasing survival rate and frequent administration of adjuvant chemotherapy treatments involving neurotoxic agents makes it imperative that accurate diagnosis, prevention, and treatment of these neurological complications be implemented.

METHODS

A consideration was undertaken of the current options regarding protective and treatment interventions for patients undergoing chemotherapy with neurotoxic chemotherapy agent or experience with CIPN. Current knowledge on the mechanism of action has also been identified. The following databases PubMed, the Cochrane Library, Science Direct, Scopus, EMBASE, MEDLINE, CINAHL, CNKI, and Google Scholar were searched for relevant article retrieval.

RESULTS

A range of pharmaceutical, nutraceutical, and herbal medicine treatments were identified that either showed efficacy or had some evidence of efficacy. Duloxetine was the most effective pharmaceutical agent for the treatment of CIPN. Vitamin E demonstrated potential for the prevention of cisplatin-IPN. Intravenous glutathione for oxaliplatin, Vitamin B6 for both oxaliplatin and cisplatin, and omega 3 fatty acids for paclitaxel have shown protection for CIPN. Acetyl-L-carnitine may provide some relief as a treatment option. Acupuncture may be of benefit for some patients and Gosha-jinki-gan may be of benefit for protection from adverse effects of oxaliplatin induced peripheral neuropathy.

CONCLUSIONS

Clinicians and researchers acknowledge that there are numerous challenges involved in understanding, preventing, and treating peripheral neuropathy caused by chemotherapeutic agents. New insights into mechanisms of action from chemotherapy agents may facilitate the development of novel preventative and treatment options, thereby enabling medical staff to better support patients by reducing this debilitating side effect.

National Cancer Institute-supported chemotherapy-induced peripheral neuropathy trials: outcomes and lessons

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common and debilitating complications of cancer treatment. Due to a lack of effective management options for patients with CIPN, the National Cancer Institute (NCI) sponsored a series of trials aimed at both prevention and treatment. A total of 15 such studies were approved, evaluating use of various neuro-modulatory agents which have shown benefit in other neuropathic pain states. Aside from duloxetine, none of the pharmacologic methods demonstrated therapeutic benefit for patients with CIPN. Despite these disappointing results, the series of trials revealed important lessons that have informed subsequent work. Some examples of this include the use of patient-reported symptom metrics, the elimination of traditional--yet unsubstantiated--practice approaches, and the discovery of molecular genetic predictors of neuropathy. Current inquiry is being guided by the results from these large-scale trials, and as such, stands better chance of identifying durable solutions for this treatment-limiting toxicity.

A model of neuropathic pain induced by sorafenib in the rat: Effect of dimiracetam

BACKGROUND

Sorafenib is a kinase inhibitor anticancer drug whose repeated administration causes the onset of a peripheral painful neuropathy. Notably, the efficacy of common analgesic drugs is not adequate and this often leads pre-mature discontinuation of anticancer therapy. The aim of this study was to establish a rat model of sorafenib-induced neuropathic pain, and to assess the effect of the new anti-neuropathic compound dimiracetam in comparison with gabapentin, pregabalin and duloxetine.

METHODS

Male Sprague-Dawley rats were treated i.v. (10 mg kg(-1)), i.p. (10 and 30 mg kg(-1)) or p.o. (80 and 160 mg kg(-1)) with sorafenib once daily for 21 days. Pain behaviour measurements (cold plate, paw pressure, electronic von Frey) were performed on days 0, 7, 14 and 21.

RESULTS

Sorafenib lowered the paw-licking threshold to non-noxious cold stimuli on day 14 of all protocols evaluated. The i.p. administration resulted in greater efficacy than the other administration routes. Sorafenib treatments did not affect paw-withdrawal responses to non-noxious or to noxious mechanical stimuli. On day 14, dimiracetam (300 mg kg(-1)), gabapentin (100 mg kg(-1)), pregabalin (30 mg kg(-1)) and duloxetine (30 mg kg(-1)) were acutely administered p.o. in sorafenib i.p.-treated rats. A single oral dose of dimiracetam induced a statistically significant increase of the pain threshold 15 min after administration. Pregabalin induced a comparable effect, whereas gabapentin and duloxetine were ineffective. Repeated twice-daily administration of dimiracetam (150 mg kg(-1) p.o.), starting on the first day of i.p sorafenib administration, significantly protected rats from sorafenib-induced decrease in the paw-licking threshold.

CONCLUSIONS

A rat model of sorafenib-induced hypersensitivity to cold stimulation has been established. Dimiracetam and pregabalin are effective in prevention of sorafenib-induced neuropathy in this model.

Therapeutic strategies for cancer treatment related peripheral neuropathies

OPINION STATEMENT

Chemotherapy-induced peripheral neuropathy (CIPN) is a common toxicity associated with multiple chemotherapeutic agents. CIPN may have a detrimental impact on patients' quality of life and functional ability, as well as result in chemotherapy dose reductions. Although symptoms of CIPN can improve with treatment completion, symptoms may persist. Currently, the treatment options for CIPN are quite limited. Duloxetine, a serotonin-norepinephrine reuptake inhibitor, has the most evidence supporting its use in the treatment of CIPN. Other agents with potential benefit for the treatment of established CIPN include gabapentinoids, venlafaxine, tricyclic antidepressants, and a topical gel consisting of the combination of amitriptyline, ketamine, and baclofen; none of these, however, has been proven to be helpful and ongoing/future studies may well show that they are not beneficial. The use of these agents is often based on their efficacy in the treatment of non-CIPN neuropathic pain, but this does not necessarily mean that they will be helpful for CIPN-related symptoms. Other nonpharmacologic interventions including acupuncture and Scrambler therapy are supported by positive preliminary data; however, further larger, placebo-controlled trial data are needed to confirm or refute their effectiveness.

Cancer treatment-related neuropathic pain syndromes--epidemiology and treatment: an update

Cancer treatment-related chronic neuropathic pain (NP) is a pervasive and distressing problem that negatively influences function and quality of life for countless cancer survivors. It occurs because of cancer treatment-induced damage to peripheral and central nervous system structures. NP becomes chronic when pain signal transmission persists, eventually sensitizing neurons in the dorsal horn and other pain-processing regions in the central nervous system. Frequently overlooked, NP due to cancer treatment has been understudied. Consequently, only a few pharmacologic interventions have been shown to be effective based on the results of randomized controlled trials. Future research designed to explore pathophysiologic mechanisms and effective mechanism-targeted interventions is sorely needed.

Platinum-induced neurotoxicity and preventive strategies: past, present, and future

Neurotoxicity is a burdensome side effect of platinum-based chemotherapy that prevents administration of the full efficacious dosage and often leads to treatment withdrawal. Peripheral sensory neurotoxicity varies from paresthesia in fingers to ataxic gait, which might be transient or irreversible. Because the number of patients being treated with these neurotoxic agents is still increasing, the need for understanding the pathogenesis of this dramatic side effect is critical. Platinum derivatives, such as cisplatin and carboplatin, harm mainly peripheral nerves and dorsal root ganglia neurons, possibly because of progressive DNA-adduct accumulation and inhibition of DNA repair pathways (e.g., extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase/stress-activated protein kinase, and p38 mitogen-activated protein kinass), which finally mediate apoptosis. Oxaliplatin, with a completely different pharmacokinetic profile, may also alter calcium-sensitive voltage-gated sodium channel kinetics through a calcium ion immobilization by oxalate residue as a calcium chelator and cause acute neurotoxicity. Polymorphisms in several genes, such as voltage-gated sodium channel genes or genes affecting the activity of pivotal metal transporters (e.g., organic cation transporters, organic cation/carnitine transporters, and some metal transporters, such as the copper transporters, and multidrug resistance-associated proteins), can also influence drug neurotoxicity and treatment response. However, most pharmacogenetics studies need to be elucidated by robust evidence. There are supportive reports about the effectiveness of several neuroprotective agents (e.g., vitamin E, glutathione, amifostine, xaliproden, and venlafaxine), but dose adjustment and/or drug withdrawal seem to be the most frequently used methods in the management of platinum-induced peripheral neurotoxicity. To develop alternative options in the treatment of platinum-induced neuropathy, studies on in vitro models and appropriate trials planning should be integrated into the future design of neuroprotective strategies to find the best patient-oriented solution.

Effect of duloxetine in Japanese patients with chemotherapy-induced peripheral neuropathy: a pilot randomized trial

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is difficult to manage. A phase III trial conducted in the United States demonstrated that duloxetine was effective for CIPN caused by taxane and platinum-based chemotherapy. No randomized trial of duloxetine for CIPN has been conducted in Japan.

METHODS

In this open-label, randomized, crossover study, eligible patients were randomized to Group A or Group B. Group A received duloxetine 20 mg/day orally for the first week and 40 mg/day for the next 3 weeks. Group B received vitamin B12 (VB12) 1.5 mg/day orally for 4 weeks. After a 2- to 4-week washout period, treatment was crossed over for another 4 weeks. The severity of numbness and pain was assessed using a visual analog scale (VAS).

RESULTS

Thirty-four patients were enrolled. Obvious decreases in the mean VAS scores for numbness and pain were observed for the periods of duloxetine administration. Significant differences were observed between the duloxetine-first (Group A) and the VB12-first (Group B) groups with respect to numbness (p = 0.03) and pain (p = 0.04) at 4 weeks after administration. Fatigue was observed in six of the 34 participants (17.6 %).

CONCLUSIONS

Our data suggests that duloxetine has a beneficial effect on CIPN caused by oxaliplatin, paclitaxel, vincristine, or bortezomib in Japanese patients.

Pharmacogenetics and analgesic effects of antidepressants in chronic pain management

Antidepressants are widely administered to chronic pain patients, but there is large interindividual variability in their efficacy and adverse effect rates that may be attributed to genetic factors. Studies have attempted to determine the impact of genetic polymorphisms in enzymes and transporters that are involved in antidepressant pharmacokinetics, for example, cytochrome P450 and P-gp. The impacts of genetic polymorphisms in the targets of antidepressants, such as the serotonin receptor or transporter, the noradrenaline transporter and the COMT and monoamine oxydase enzymes, have also been described. This manuscript discusses the current knowledge of the influence of genetic factors on the plasma concentrations, efficacy and adverse effects of the major antidepressants used in pain management.

Basic science and clinical management of painful and non-painful chemotherapy-related neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting toxicity of several chemotherapeutics used in the treatment of all the most common malignancies. There are several defined mechanisms of nerve damage that take place along different areas of the peripheral and the central nervous system. Treatment is based on symptom management and there are several classes of medications found to be efficacious in the treatment of neuropathic pain. Neuropathic pain that persists despite appropriate pharmacotherapy may respond to interventional procedures that span a range of invasiveness. The purpose of this review article is to examine the basic science of neuropathy and currently available treatment options in the context of chemotherapy induced peripheral neuropathy.

Nortriptyline for neuropathic pain in adults

BACKGROUND

Antidepressants are widely used to treat chronic neuropathic pain (pain due to nerve damage), usually in doses below those at which they exert antidepressant effects. An earlier review that included all antidepressants for neuropathic pain is being replaced by new reviews of individual drugs examining individual neuropathic pain conditions.Nortriptyline is a tricyclic antidepressant that is occasionally used for treating neuropathic pain, and is recommended in European, UK, and USA guidelines.

OBJECTIVES

To assess the analgesic efficacy and associated adverse events of nortriptyline for chronic neuropathic pain in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE from inception to 7 January 2015, and the reference lists of retrieved papers and other reviews. We also searched two clinical trials databases for ongoing or unpublished studies.

SELECTION CRITERIA

We included randomised, double-blind studies of at least two weeks' duration comparing nortriptyline with placebo or another active treatment in chronic neuropathic pain. Participants were adults aged 18 years and over. We included only full journal publication articles and clinical trial summaries.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted efficacy and adverse event data, and examined issues of study quality. We considered the evidence using three tiers. First tier evidence derived from data meeting current best standards and subject to minimal risk of bias (outcome equivalent to substantial pain intensity reduction, intention-to-treat analysis without imputation for dropouts; at least 200 participants in the comparison, 8 to 12 weeks' duration, parallel design); second tier evidence from data that failed to meet one or more of these criteria and were considered at some risk of bias but with adequate numbers in the comparison; and third tier evidence from data involving small numbers of participants that was considered very likely to be biased or used outcomes of limited clinical utility, or both.We planned to calculate risk ratio (RR) and numbers needed to treat for an additional beneficial outcome (NNT) and harmful outcome (NNH) using standard methods expected by The Cochrane Collaboration.

MAIN RESULTS

We included six studies treating 310 participants (mean or median age 49 to 64 years) with various neuropathic pain conditions. Five studies used a cross-over design, and one used a parallel-group design; 272 participants were randomised to treatment with nortriptyline, 145 to placebo, 94 to gabapentin, 56 to gabapentin plus nortriptyline, 55 to morphine, 55 to morphine plus nortriptyline, 39 to chlorimipramine, and 33 to amitriptyline. Treatment periods lasted from three to eight weeks. All studies had one or more sources of potential major bias.No study provided first or second tier evidence for any outcome. Only one study reported our primary outcome of people with at least 50% reduction in pain. There was no indication that either nortriptyline or gabapentin was more effective in postherpetic neuralgia (very low quality evidence). Two studies reported the number of people with at least moderate pain relief, and one reported the number who were satisfied with their pain relief and had tolerable adverse effects. We considered these outcomes to be equivalent to our other primary outcome of Patient Global Impression of Change (PGIC) much or very much improved.We could not pool data, but third tier evidence in individual studies indicated similar efficacy to other active interventions (gabapentin, morphine, chlorimipramine, and amitriptyline), and to placebo in the conditions studied (very low quality evidence). Adverse event reporting was inconsistent and fragmented. More participants reported adverse events with nortriptyline than with placebo, similar numbers with nortriptyline and other antidepressants (amitriptyline and chlorimipramine) and gabapentin, and slightly more with morphine (very low quality evidence). No study reported any serious adverse events or deaths.

AUTHORS' CONCLUSIONS

We found little evidence to support the use of nortriptyline to treat the neuropathic pain conditions included in this review. There were no studies in the treatment of trigeminal neuralgia. The studies were methodologically flawed, largely due to small size, and potentially subject to major bias. The results of this review do not support the use of nortriptyline as a first line treatment. Effective medicines with much greater supportive evidence are available, such as duloxetine and pregabalin.

Symptoms: Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a problematic, treatment-induced toxicity that has the potential to impact quality of life and limit the doses of curative intent therapy. This therapy-induced side effect is one of the most troublesome in oncology clinical practices, considering the morbidity, the frequency, and the potential irreversibility of this problem. Patients with breast cancer are particularly impacted by this side effect as multiple agents commonly used for this disease can cause neuropathy. In this chapter, we provide an overview of CIPN, including: clinical predictors, frequency, and its impact on quality of life. Further, we highlight the pathophysiology and review the literature to date for agents designed to prevent or treat CIPN. We also highlight the most important ongoing clinical and translational research questions that hope to help better predict and prevent this toxicity. This includes optimizing the methods of assessment, using host specific factors (Race and genetics) to predict those more likely to experience CIPN, and determining how CIPN might impact clinical decisions toward therapy.

Neuronal and immunological basis of action of antidepressants in chronic pain - clinical and experimental studies

The current knowledge of the pharmacological actions of the tricyclic antidepressants (TCAs) has slowly evolved through their over 40-year history. Chronic pain represents one of the most important public health problems, and antidepressants are an essential part of the therapeutic strategy in addition to classical analgesics. This article reviews the available evidence on the efficacy and safety of antidepressants in chronic pain conditions; namely, headaches, low back pain, fibromyalgia, cancer pain and especially neuropathic pain. TCAs are traditionally the main type of depression medication used to treat chronic pain. Recently, new antidepressants were introduced into clinical use, with a significant reduction in side effects and equivalent efficacy on mood disorders. These new drugs that are effective for chronic pain belong to the tetracyclic antidepressants (TeCAs) group (amoxapine, maprotiline), the serotonin and noradrenaline reuptake inhibitors (SNRIs) group (duloxetine, venlafaxine, milnacipran) and the atypical antidepressants group (bupropion, trazodone, mirtazapine, nefazodone). In this review, we present the available publications on TCAs (amitriptyline, doxepin, imipramine, desipramine, nortriptyline), TeCAs (amoxapine, maprotiline), selective serotonin reuptake inhibitors (SSRIs) (citalopram, fluoxetine, paroxetine), SNRIs (duloxetine, venlafaxine, milnacipran) and atypical antidepressants (bupropion) for the treatment of neuropathic pain. We also review analgesics acting as both opioid receptor agonists and also acting as aminergic reuptake inhibitors. Existing data are insufficient to conclude which of these new classes of antidepressants has the best clinical profile and will be the most effective in the treatment of neuropathic pain; in addition, a lower incidence of side effects should be considered. Increased experimental and translational research is a key for further improvement of the treatment of chronic pain with antidepressants. However, evidence from basic science is needed to improve our understanding of the mechanisms of action and their possible pharmacodynamic interactions.

Current use of drugs affecting the central nervous system for chemotherapy-induced peripheral neuropathy in cancer patients: a systematic review

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is common among cancer patients who undergo chemotherapy with platinum analogues, taxanes, vinca alkaloids, epothilone, bortezomib, and thalidomide. The purpose of this study was to investigate the evidence of using drugs affecting the central nervous system (CNS) to alleviate CIPN in cancer patients.

METHODS

A systematic literature search was conducted using the CINAHL, EMBASE, and Medline databases to identify randomized controlled clinical trials (RCTs) reported in English up to 2013. We identified ten trials of CNS-acting drugs used to treat CIPN in cancer patients and reviewed efficacy and safety of CNS-acting drugs for CIPN using a standard data collection form. The risk of bias in each RCT was also assessed.

RESULTS

Antidepressants were used in six studies and anticonvulsants in four studies. We found positive results for amitriptyline (topical), venlafaxine, and oxcarbazepine in one study each, but the results were not sufficient to draw definite conclusions. One trial with duloxetine showed a moderate effect (effect size, 0.513, P = .003) on CIPN pain relief. However, none of the results has yet been duplicated in an RCT with a large sample size.

CONCLUSIONS

Insufficient RCTs exist to confirm the efficacy of CNS agents to reduce CIPN. This study highlighted the need for and the importance of conducting well-designed RCTs to generate evidence on CIPN symptom management. Additional RCTs are warranted to accelerate the potential use of CNS drugs for CIPN in cancer patients.

Pilot evaluation of Scrambler therapy for the treatment of chemotherapy-induced peripheral neuropathy

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN), a common side effect of chemotherapy, needs better effective treatments. Preliminary data support the use of Scrambler therapy, a device which treats pain via noninvasive cutaneous electrostimulation, for the treatment of CIPN. The current manuscript reports data from a pilot trial, performed to investigate the effect of Scrambler therapy for the treatment of established CIPN.

METHODS

Eligible patients had CIPN symptoms of ≥1 month duration with tingling and/or pain ≥4/10 during the prior week. Patients were treated with Scrambler therapy to the affected area(s) for up to ten daily 30-min sessions. Symptoms were monitored using a neuropathy questionnaire consisting of numerical analog scales ranging from 0 to 10, daily before therapy as well as weekly for 10 weeks after therapy. Descriptive summary statistics formed the basis of data analysis.

RESULTS

Thirty-seven patients were enrolled. Twenty-five patients were treated primarily on their lower extremities while 12 were treated primarily on their upper extremities. There was a 53 % reduction in pain score from baseline to day 10; a 44 % reduction in tingling; and a 37 % reduction in numbness. Benefit appeared to last throughout 10 weeks of follow-up. There were no substantial adverse events.

CONCLUSION

Preliminary data support that Scrambler therapy may be effective for the treatment of CIPN: a prospective placebo-controlled clinical trial should be performed.

Incidence, prevalence, and predictors of chemotherapy-induced peripheral neuropathy: A systematic review and meta-analysis

Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling pain condition resulting from chemotherapy for cancer. Severe acute CIPN may require chemotherapy dose reduction or cessation. There is no effective CIPN prevention strategy; treatment of established chronic CIPN is limited, and the prevalence of CIPN is not known. Here we used a systematic review to identify studies reporting the prevalence of CIPN. We searched Embase, Medline, CAB Abstracts, CINAHL, PubMed central, Cochrane Library, and Web of Knowledge for relevant references and used random-effects meta-regression to estimate overall prevalence. We assessed study quality using the CONSORT and STROBE guidelines, and we report findings according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. We provide a qualitative summary of factors reported to alter the risk of CIPN. We included 31 studies with data from 4179 patients in our analysis. CIPN prevalence was 68.1% (57.7-78.4) when measured in the first month after chemotherapy, 60.0% (36.4-81.6) at 3months and 30.0% (6.4-53.5) at 6months or more. Different chemotherapy drugs were associated with differences in CIPN prevalence, and there was some evidence of publication bias. Genetic risk factors were reported in 4 studies. Clinical risk factors, identified in 4 of 31 studies, included neuropathy at baseline, smoking, abnormal creatinine clearance, and specific sensory changes during chemotherapy. Although CIPN prevalence decreases with time, at 6months 30% of patients continue to suffer from CIPN. Routine CIPN surveillance during post-chemotherapy follow-up is needed. A number of genetic and clinical risk factors were identified that require further study.

Pain in the cancer patient: different pain characteristics CHANGE pharmacological treatment requirements

Twenty years ago, the main barriers to successful cancer pain management were poor assessment by physicians, and patients' reluctance to report pain and take opioids. Those barriers are almost exactly the same today. Cancer pain remains under-treated; in Europe, almost three-quarters of cancer patients experience pain, and almost a quarter of those with moderate to severe pain do not receive any analgesic medication. Yet it has been suggested that pain management could be improved simply by ensuring that every consultation includes the patient's rating of pain, that the physician pays attention to this rating, and a plan is agreed to increase analgesia when it is inadequate. After outlining current concepts of carcinogenesis in some detail, this paper describes different methods of classifying and diagnosing cancer pain and the extent of current under-treatment. Key points are made regarding cancer pain management. Firstly, the pain may be caused by multiple different mechanisms and therapy should reflect those underlying mechanisms - rather than being simply based on pain intensity as recommended by the WHO three-step ladder. Secondly, a multidisciplinary approach is required which combines both pharmacological and non-pharmacological treatment, such as psychotherapy, exercise therapy and electrostimulation. The choice of analgesic agent and its route of administration are considered, along with various interventional procedures and the requirements of palliative care. Special attention is paid to the treatment of breakthrough pain (particularly with fast-acting fentanyl formulations, which have pharmacokinetic profiles that closely match those of breakthrough pain episodes) and chemotherapy-induced neuropathic pain, which affects around one third of patients who receive chemotherapy. Finally, the point is made that medical education should place a greater emphasis on pain therapy, both at undergraduate and postgraduate level.

Prevention and treatment of chemotherapy-induced peripheral neuropathy

PURPOSE

The prevention and treatment of chemotherapy-induced peripheral neuropathy (CIPN) are reviewed.

SUMMARY

A number of agents, including amifostine, glutathione, and vitamin E, were evaluated as prevention strategies for CIPN, with no agent demonstrating efficacy. Calcium and magnesium are effective for the prevention of CIPN; however, concerns regarding reduced chemotherapy efficacy linger. Venlafaxine, a serotonin-norepinephrine reuptake inhibitor (SNRI), was evaluated for the prevention of neuropathy in a randomized, double-blind, placebo-controlled Phase III trial of patients receiving an oxaliplatin-based regimens every two weeks and demonstrated significantly less acute neurotoxicity compared with the control group. Treatment options for CIPN include reducing the dosage of the chemotherapy, changing the chemotherapy, and treating CIPN with adjunct therapy. Adjunct therapy with topical agents, tricyclic antidepressants, and anticonvulsants, such as pregabalin and gabapentin, have shown limited efficacy. However, a randomized, double-blind, crossover, Phase III trial of duloxetine versus placebo for the treatment of CIPN caused by paclitaxel or oxaliplatin found that patients treated with duloxetine 60 mg daily had a larger average decrease in pain score than those receiving placebo, regardless of the chemotherapy used.

CONCLUSION

Calcium and magnesium infusions and venlafaxine are effective in preventing CIPN but are not routinely used because of concerns related to decreased chemotherapy efficacy. Adjunct treatment options for CIPN include a topical analgesic, a tricyclic antidepressant, an anticonvulsant, or an SNRI. Duloxetine is more effective than placebo in treating oxaliplatin- or paclitaxel-induced CIPN, is well tolerated, and should be considered to be a first-line treatment option for CIPN.