Amitriptyline in neuropathic cancer pain in patients on morphine therapy: a randomized placebo-controlled, double-blind crossover study. Intra-articular botulinum toxin A for refractory shoulder pain: a randomized, double-blinded, placebo-controlled trial. Oral opioid therapy for chronic peripheral and central neuropathic pain. Gabapentin in neuropathic pain syndromes: a randomised, double-blind, placebo-controlled trial. The response of neuropathic pain and pain in complex regional pain syndrome I to carbamazepine and sustained-release morphine in patients pretreated with spinal cord stimulation: a double-blinded randomized study. Pain after open preperitoneal repair versus Lichtenstein repair: a randomized trial. Gabapentin is a first line drug for the treatment of neuropathic pain in spinal cord injury. Effects of anodal transcranial direct current stimulation on chronic neuropathic pain in patients with multiple sclerosis. Efficacy of gabapentin in treating chronic phantom limb and residual limb pain. A pilot study investigating the effects of fast left prefrontal rTMS on chronic neuropathic pain. Oxcarbazepine in painful diabetic neuropathy: a randomized, placebo-controlled study. The use of oral mexiletine for the treatment of pain after peripheral nerve injury. Lack of analgesic effect of opioids on neuropathic and idiopathic forms of pain. Physical activity for men receiving androgen deprivation therapy for prostate cancer: benefits from a 16-week intervention.
Amitriptyline is the most common analgesic adjuvant used in cancer patients with neuropathic pain, even though no specific studies have demonstrated a benefit. A randomized placebo-controlled, double-blind crossover study was designed to evidence the effects of amitriptyline in patients with neuropathic cancer pain.
                Sixteen advanced cancer patients with neuropathic pain on systemic morphine therapy, no longer receiving oncologic treatment, presenting moderate pain (about 4 or more, but less than 7, on a numerical scale of 0-10) in the last week, and given a stable morphine dose in the last 2 days were admitted to the study. During the first week of study, patients were administered 25 mg of amitriptyline or equivalent drops of placebo at night for 3 days and 50 mg for the following 4 days. Doses for patients aged more than 65 years were 15 mg (first 3 days) and 30 mg (3 days after). After a week, a crossover took place for the second week, with the other treatment at an inverse sequence. Opioid consumption, pain intensity, symptoms and adverse effects, mood, sleep, patient's preference, quality of life before starting the study, the first week after and the second week after were recorded.
                No significant benefits in analgesia were found in the global pain intensity of the previous week of treatment, the least pain intensity or the pain evaluated just after a week of treatment, at the moment of the visit, when amitriptyline was compared with placebo. A significant difference was evidenced for the worst pain (P < 0.035). No differences in opioid doses during the period of study were found. Drowsiness, confusion and dry mouth were significantly more intense with amitriptyline than with placebo (P < 0.036, 0.003, and 0.034, respectively). There were no substantial differences between the two treatments in Spitzer's quality of life score and for each item. No differences in patients' preference for the two treatment periods were found. The analgesic effects of amitriptyline were slight and associated with adverse effects.
                In light of the results obtained in the study, the extensive use of the drug for cancer pain should be questioned. We compared the short-term efficacy and safety of intra-articular (IA) botulinum toxin A (BoNT/A) to IA-placebo in patients with chronic, refractory shoulder joint pain. Forty-three shoulder joints in patients with moderate-to-severe shoulder arthritis pain were randomized to receive (1) 100 units IA-BoNT/A + lidocaine or (2) IA-saline + lidocaine. The following outcomes were compared using analysis of covariance: (1) primary: change in pain severity on a visual analog scale at 1 month (VAS, 0 cm to 10 cm); (2) secondary: Shoulder Pain and Disability Index (SPADI) disability subscale, quality of life on short-form (SF)-36 subscales, percent of patients who achieved at least a 30% decrease or a 2-point reduction in VAS pain (clinically meaningful pain relief), and safety. Both BoNT/A (n = 21) and placebo (n = 22) groups were comparable at baseline. At 1 month post-injection, the VAS pain reduction was significantly more in the BoNT/A group versus the placebo group (-2.4 vs -0.8; P-value = 0.014). When comparing BoNT/A with the placebo group at 1 month, it was observed that 5 SF-36 subscale scores improved significantly (P </= 0.035), and the SPADI disability improved more with a trend toward significance (51.5 +/- 4.4 vs 64.9 +/- 3.9; P = 0.083). In addition, clinically meaningful pain relief occurred in 61% versus 36% patients (P = 0.22). The total number of adverse events was similar, which included 50 events in the BoNT/A group versus 46 events in the placebo group. A single injection of BoNT/A produced statistically significant and clinically meaningful pain relief and improvement in quality of life in patients with chronic refractory moderate/severe shoulder arthritis pain at 1 month. These data provide evidence to support the efficacy of this novel neurotoxin therapy that needs to be confirmed in a multicenter, randomized trial. Although opioids are commonly used to treat chronic neuropathic pain, there are limited data to guide their use. Few controlled trials have been performed, and many types of neuropathic pain remain unstudied.
                Adults with neuropathic pain that was refractory to treatment were randomly assigned to receive either high-strength (0.75-mg) or low-strength (0.15-mg) capsules of the potent mu-opioid agonist levorphanol for eight weeks under double-blind conditions. Intake was titrated by the patient to a maximum of 21 capsules of either strength per day. Outcome measures included the intensity of pain as recorded in a diary, the degree of pain relief, quality of life, psychological and cognitive function, the number of capsules taken daily, and blood levorphanol levels.
                Among the 81 patients exposed to the study drug, high-strength levorphanol capsules reduced pain by 36 percent, as compared with a 21 percent reduction in pain in the low-strength group (P=0.02). On average, patients in the high-strength group took 11.9 capsules per day (8.9 mg per day) and patients in the low-strength group took close to the 21 allowed (18.3 capsules per day; 2.7 mg per day). Affective distress and interference with functioning were reduced, and sleep was improved, but there were no differences between the high-strength group and the low-strength group in terms of these variables. Noncompletion of the study was primarily due to side effects of the opioid. Patients with central pain after stroke were the least likely to report benefit.
                The reduction in the intensity of neuropathic pain was significantly greater during treatment with higher doses of opioids than with lower doses. Higher doses produced more side effects without significant additional benefit in terms of other outcome measures.
                Copyright 2003 Massachusetts Medical Society A double-blind, randomised, placebo-controlled 8-week study was conducted to evaluate the efficacy and safety of gabapentin in the treatment of neuropathic pain, using doses up to 2400 mg/day. The study used a novel design that was symptom- rather than syndrome-based; an approach that aimed to reflect the realities of clinical practice. Participants had a wide range of neuropathic pain syndromes, with at least two of the following symptoms: allodynia, burning pain, shooting pain, or hyperalgesia. Patients were randomised to gabapentin (n=153) or placebo (n=152). Gabapentin was given in three divided doses, initially titrated to 900 mg/day over 3 days, followed by two further increases, to a maximum of 2400 mg/day if required by the end of week 5. The primary outcome measure was changed in average daily pain diary score (baseline versus final week). Over the 8 week study, this score decreased (i.e. improved) by 1.5 (21%) in gabapentin treated patients and by 1.0 (14%) in placebo treated patients (P=0.048, rank-based analysis of covariance). Significant differences were shown in favour of gabapentin (P<0.05) for the Clinician and Patient Global Impression of Change, and some domains of the Short Form-McGill Pain Questionnaire. Improvements were also shown in patient-reported outcomes in quality of life, as seen by significant differences in favour of gabapentin in several domains of the Short-Form-36 Health Survey. Gabapentin was well tolerated and the majority of patients completed the study (79 versus 73% for placebo). The most common adverse events were mild to moderate dizziness and somnolence, most of which were transient and occurred during the titration phase. This study shows that gabapentin reduces pain and improves some quality-of-life measures in patients with a wide range of neuropathic pain syndromes. Forty-three patients with peripheral neuropathic pain, exclusively pain reduced by spinal cord stimulation (SCS), were switched into a painful state after SCS inactivation. This mode was used to assess the pain-relieving effect of carbamazepine (CMZ) and opioids in a double-blinded, placebo-controlled trial. In Phase 1, the patients were randomly allocated to receive either CMZ (600 mg/d) or placebo during an SCS-free period of 8 days. In Phase 2, after a CMZ elimination interval of 7 days, 38 patients received either sustained-release morphine (90 mg/d) or placebo for 8 days. In cases of intolerable pain, the patients were authorized to reactivate their SCS. The pain intensity was rated on a numeric analog scale. In 38 patients who completed Phase 1, significant delay in pain increase was observed in the CMZ group as compared with placebo (P = 0.038). In Phase 2, the trend observed with morphine was insignificant (P = 0.41). Two CMZ patients and one morphine patient showed complete pain relief and preferred to continue the medication. Thirty-five patients returned to SCS. We conclude that CMZ is effective in peripheral neuropathic pain. Morphine obviously requires larger individually titrated dosages than those used in this study for results to be adequately interpreted. The open preperitoneal approach in inguinal hernia repair might have the benefit of a mesh in the preferred space without the disadvantages of an endoscopic procedure.
                A total of 172 patients with primary inguinal hernia were randomized to undergo the open preperitoneal Kugel or the standard open anterior Lichtenstein procedure in a teaching hospital. The main outcome measures were operating variables, visual analog scale (VAS) pain scores, and consumed analgesics during the first 2 weeks postoperatively and at 3 months, neurological examination, and complications.
                In the Lichtenstein group the operation took longer (54 min versus 41 min; p < .001). There were no clinically important differences in VAS pain score or number of analgesics during the first 2 weeks postoperatively. In the Kugel group the mean VAS pain score at 3 months was less (0.3 versus 0.9; p = .002), as was the proportion of patients reporting pain (21 versus 40%; p = .007). Pain was merely described as neuropathic, especially in the Lichtenstein group. With the anterior repair significantly more nerves were encountered, numbness reported, and cutaneous sensory changes found with neurological examination (all p < .001).
                For those surgeons preferring an open approach, the Kugel procedure is a feasible alternative for the standard Lichtenstein procedure and is associated with less chronic pain at three months. Most likely the neuropathic pain and numbness with the Lichtenstein technique are results of more nerves at risk with the anterior approach. Prospective, randomized, double blind, placebo-controlled, crossover clinical trial.
                To determine the efficacy of gabapentin in the treatment of neuropathic pain related to spinal cord injury.
                Neuropathic pain is initiated or caused by a primary lesion or dysfunction in the nervous system. Neuropathic pain associated with spinal cord injury is quite refractory, and current treatments are not effective. Gabapentin, an anticonvulsant, has become the first choice in the treatment of neuropathic pain. The place of gabapentin in the treatment of spinal cord injury-related neuropathic pain was questioned in only a few recent reports; however, they are retrospectively designed, nonstandardized, and uncontrolled studies, or involve a very small series of patients using less than optimum doses.
                A total of 18-week study period included a 4-week medication/placebo titration period. This was followed by a 4-week stable dosing period when the patients continued to receive maximum tolerated doses, a 2-week washout period, then a crossover of 4 weeks of medication/placebo titration, and another 4 weeks of stable dosing period. Twenty paraplegic patients (female/male: 7/13) with complete spinal cord injury at the thoracic and lumbar level, aged between 20 and 65 years, with neuropathic pain for more than 6 months were recruited for the study.
                All patients completed the study. Gabapentin reduced the intensity as well as the frequency of pain, relieved all neuropathic pain descriptors except the itchy, sensitive, dull, and cold types, and improved the quality of life (P < 0.05).
                Gabapentin can be added to the list of first-line medications for the treatment of chronic neuropathic pain in spinal cord injury patients. It is a promising new agent and offers advantages over currently available treatments. Neuropathic pain in patients with MS is frequent and is associated with a great interference with daily life activities. In the present study, we investigated whether anodal transcranial direct current stimulation (tDCS) may be effective in reducing central chronic pain in MS patients. Patients received sham tDCS or real tDCS in a 5-day period of treatment in a randomized, double blind, sham-controlled study. Pain was measured using visual analog scale (VAS) for pain and the short form McGill questionnaire (SF-MPQ). Quality of life was measured using the Multiple Sclerosis Quality of Life-54 scale (MSQoL-54). Depressive symptoms and anxiety were also evaluated as confounding factors using the Beck Depression Inventory (BDI) and VAS for anxiety. Evaluations were performed at baseline, immediately after the end of treatment, and once a week during a 3-week follow-up period. Following anodal but not sham tDCS over the motor cortex, there was a significant pain improvement as assessed by VAS for pain and McGill questionnaire, and of overall quality of life. No depression or anxiety changes were observed. Our results show that anodal tDCS is able to reduce pain-scale scores in MS patients with central chronic pain and that this effect outlasts the period of stimulation, leading to long-lasting clinical effects.
                This article presents a new, noninvasive therapeutic approach to chronic, central neuropathic pain in multiple sclerosis, poorly responsive to current conventional medications. tDCS is known to cause long-lasting changes of neuronal excitability at the site of stimulation and in the connected areas in healthy subjects. This led us to hypothesize that pain decrease may be the result of functional plastic changes in brain structures involved in the pathogenesis of chronic neuropathic pain.
                Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved. Twenty-four adults with phantom limb pain (PLP) and/or residual limb pain (RLP) participated in a double-blind crossover trial. Participants were randomly assigned to receive gabapentin or placebo and later crossed over to the other treatment, with a 5-week washout interval in which they did not receive medication. Gabapentin was titrated from 300 mg to the maximum dose of 3,600 mg. Measures of pain intensity, pain interference, depression, life satisfaction, and functioning were collected throughout the study. Analyses revealed no significant group differences in pre- to posttreatment change scores on any of the outcome measures. More than half of the participants reported a meaningful decrease in pain during the gabapentin phase compared with about one-fifth who reported a meaningful decrease in pain during the placebo phase. In this trial, gabapentin did not substantially affect pain. More research on the efficacy of gabapentin to treat chronic PLP and RLP is needed. Stimulating the human cortex using transcranial magnetic stimulation (TMS) temporarily reduces clinical and experimental pain; however, it is unclear which cortical targets are the most effective. The motor cortex has been a popular target for managing neuropathic pain, while the prefrontal cortex has been investigated for an array of nociceptive pain conditions. It is unclear whether the motor cortex is the only effective cortical target for managing neuropathic pain, and no published studies to date have investigated the effects of prefrontal stimulation on neuropathic pain.
                This preliminary pilot trial employed a sham-controlled, within-subject, crossover design to evaluate clinical pain as well as laboratory pain thresholds among four patients with chronic neuropathic pain. Each participant underwent three real and three sham 20-minute sessions of 10 Hz left prefrontal repetitive TMS. Daily pain diaries were collected for 3 weeks before and after each treatment phase along with a battery of self-report pain and mood questionnaires.
                Time-series analysis at the individual patient level indicated that real TMS was associated with significant improvements in average daily pain in 3 of the 4 participants. These effects were independent of changes in mood in two of the participants. At the group level, a decrease of 19% in daily pain on average, pain at its worst, and pain at its least was observed while controlling for changes in mood, activity level and sleep. The effects of real TMS were significantly greater than sham. Real TMS was associated with increases in thermal and mechanical pain thresholds, whereas sham was not. No statistically significant effects were observed across the questionnaire data.
                The prefrontal cortex may be an important TMS cortical target for managing certain types of pain, including certain neuropathic pain syndromes. In this multicentre, placebo-controlled, 16-week trial, the efficacy and safety of oxcarbazepine monotherapy in patients with neuropathic pain of diabetic origin was evaluated. Eligible patients had a 6-month to 5-year history of neuropathic pain symptoms of diabetic origin and a pain rating of > or =50 units on the visual analogue scale (VAS). Oxcarbazepine was initiated at a dose of 300 mg/day and titrated to a maximum dose of 1800 mg/day. In total, 146 patients (oxcarbazepine, n=69; placebo, n=77) were randomized. After 16 weeks, oxcarbazepine-treated patients experienced a significantly larger decrease in the average change in VAS score from baseline compared with placebo (-24.3 vs. -14.7 units, respectively; p=0.01). The reduction from baseline in mean VAS score for oxcarbazepine-treated patients was of a greater magnitude than placebo as early as week 2 (-8.0 vs. -4.7; p<0.05). A significantly greater proportion of oxcarbazepine-treated patients experienced a >50% reduction from baseline in VAS score at the end of treatment compared with placebo (35.2% vs. 18.4%, respectively; p=0.0156; number needed to treat=6.0). Global assessment of therapeutic effect rating was improved in more oxcarbazepine patients than placebo patients (48% vs. 22%, respectively; p=0.0025). Patients on oxcarbazepine were awakened less frequently due to pain than patients on placebo. Most adverse events were mild to moderate in severity, transient, and in line with the known tolerability profile of oxcarbazepine. These observations suggest that oxcarbazepine monotherapy, pending additional trials, may be efficacious and may provide clinically meaningful pain relief in patients with neuropathic pain of diabetic origin. Neuropathic pain is often a difficult condition to treat. Clinical and laboratory studies using intravenously administered local anesthetics or antiarrhythmic agents support the use of these drugs for the treatment of neuropathic pain. The availability of the oral antiarrhythmic medication, mexiletine, has made it possible to study the effects of an orally administered medication on chronic neuropathic pain. The study used a double-blind placebo-controlled design to examine 11 subjects in whom treatment with conventional pain medications had been unsuccessful. Subjects had a history of peripheral nerve injury or dysfunction, and all complained of symptoms consistent with neuropathic pain. After baseline pain measurements, mexiletine or placebo was given in gradually increasing doses to a maximum daily dose of 750 mg mexiletine. After 1 month at steady state, the subject received the alternative medication. Mexiletine was found to produce a statistically significant reduction in reported pain when compared to baseline or placebo. Pain scores were rated on a scale from 0 (no pain) to 10 (unbearable pain). Median pain scores prior to mexiletine were 7, after placebo treatment 7, and while receiving mexiletine (750 mg/day) 4. Side effects were mild and well-tolerated. Mexiletine may be effective in reducing neuropathic pain for patients in whom alternative pain medications have been unsatisfactory. The aim of the present study has been to assess the responsiveness of various types of chronic pain to opioids given i.v. and tested against placebo in a double-blind, randomized fashion. Pain classified as primary nociceptive was effectively alleviated (P greater than 0.001) while neuropathic deafferentation pain was not significantly influenced by morphine or equivalent doses of other opioids. Also 'idiopathic' pain, defined as chronic pain with no or little demonstrable pathology, failed to respond. The results were not related to whether the patients were regular users of narcotic analgesics or not. The outcome of our double-blind opioid test has proved useful to justify a continued, or discontinued, use of narcotic medication in individual patients. It may also support the indication and choice of invasive stimulation procedures (spinal cord or brain). The results of the study illustrate the misconception of chronic pain as an entity and highlight the importance of recognizing different neurobiological mechanisms and differences in responsiveness to analgesic drugs as well as to non-pharmacological modes of treatment. The opioid test has thus become a valuable tool in pain analysis and helpful as a guide for further treatment. Prostate cancer patients receiving androgen deprivation therapy (ADT) are vulnerable to a number of potentially debilitating side effects, which can significantly impact quality of life. The role of alternate therapies, such as physical activity (PA), in attenuating these side effects is largely understudied for such a large population. Thus, the purpose of this study was to investigate the effects of PA intervention for men receiving ADT on PA behavior, quality of life, and fitness measures.
                One hundred participants were randomized into an intervention (n = 53) or a wait-list control group (n = 47), with 11 dropping out of the intervention group and 23 dropping out of the wait-list control group prior to post-testing. The intervention consisted of both an individually tailored home-based aerobic and light resistant training program and weekly group sessions. PA, quality of life, fitness, and physiological outcomes were assessed pre and post the 16-week intervention.
                Significant increases in PA, supported by changes in girth measures and blood pressure, support the beneficial impact of the intervention. Positive trends were also evident for depression and fatigue. However, due to the high dropout rate, these results must be interpreted with caution.
                PA effectively attenuates many of the side effects of ADT and should be recommended to prostate survivors as an alternate therapy. Determining the maintenance of this behavior change will be important for understanding how the long-term benefits of increased activity levels may alleviate the late effects of ADT.
Carbamazepine is effective in chronic neuropathic pain, with caveats. No trial was longer than four weeks, of good reporting quality, using outcomes equivalent to at least moderate clinical benefit. In these circumstances, caution is needed in interpretation, and meaningful comparison with other interventions is not possible.