Double-blind, placebo-controlled trial of lamotrigine in combination with other medications for neuropathic pain

This randomized, double-blind, placebo-controlled study was undertaken to evaluate the efficacy and tolerability of lamotrigine added to gabapentin, a tricyclic antidepressant, or a nonopioid analgesic in patients whose neuropathic pain was inadequately controlled with these medications. Patients with neuropathic pain from diabetic peripheral neuropathy, postherpetic neuralgia, traumatic/surgical nerve injury, incomplete spinal cord injury, trigeminal neuralgia, multiple sclerosis, or HIV-associated peripheral neuropathy, who had a mean weekly pain score > or =4 on an 11-point numerical rating scale, were randomized to receive a flexible dose of lamotrigine 200, 300, or 400mg daily (n=111) or placebo (n=109) for up to 14 weeks (including eight weeks of dose escalation) in addition to their prestudy regimen of gabapentin, a tricyclic antidepressant, or a nonopioid analgesic. No statistically significant difference in the mean change in pain-intensity score from baseline to Week 14 (primary endpoint) was detected between lamotrigine and placebo (P=0.67). Differences between lamotrigine and placebo were not statistically significant for secondary efficacy assessments, including mean changes from baseline in the Short-Form McGill Pain Questionnaire, the Neuropathic Pain Scale, rescue medication use, and the percentages of patients rated as much improved or very much improved at the end of treatment on the Clinician Global Impression of Change scale and the Patient Global Impression of Change scale. Lamotrigine was generally well tolerated. Lamotrigine (up to 400 mg/day) added to gabapentin, a tricyclic antidepressant, or a nonopioid analgesic did not demonstrate efficacy as an adjunctive treatment of neuropathic pain but was generally safe and well tolerated.     

Gabapentin in postherpetic neuralgia: a randomised, double blind, placebo controlled study.

A multicentre double blind, randomised, placebo controlled 7-week study evaluated the efficacy and safety of gabapentin 1800 or 2400 mg/day in treating postherpetic neuralgia. Three hundred and thirty-four men and women aged at least 18 years (mean 73) received gabapentin 1800 or 2400 mg daily or placebo in three divided doses with a forced titration schedule. The primary outcome measure was change in average daily pain diary score (baseline week v final week). Secondary outcomes included mean weekly sleep interference score; Short Form-McGill Pain Questionnaire (SF-MPQ); Clinician and Patient Global Impression of Change (CGIC/PGIC); Short Form-36 Health Survey (SF-36). From week 1, pain scores showed a significantly greater improvement with gabapentin: the final difference v baseline was -34.5% for the 1800 mg dose, -34.4% for the 2400 mg dose compared with -15.7% for the placebo group. The difference vs. placebo was 18.8% for the 1800 mg dose (95% confidence interval 10.9-26.8%; P<0.01) and 18.7% for the 2400 mg dose (10.7-26.7%; P<0.01). Sleep interference diaries showed a similar pattern. There were significant differences in favour of gabapentin for number of patients reporting >50% reduction in their pain intensity, in the CGIC and PGIC, in the sensory and total scores of the SF-MPQ (both doses), in the visual analogue scale of pain of the SF-MPQ (2400 mg only) and in the vitality, bodily pain and mental health domains of the SF-36. Overall gabapentin was well tolerated. The most common adverse events were dizziness and somnolence, particularly during the titration phase. Thus, this study confirms the role of gabapentin as an efficacious and well-tolerated treatment for postherpetic neuralgia.     

Gabapentin in neuropathic pain syndromes: a randomised,double-blind,placebo-controlled trial

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.     

Pregabalin for relief of neuropathic pain associated with diabetic neuropathy: A randomized,double‐blind study

Seven published, randomized, placebo‐controlled clinical trials with pregabalin have shown robust efficacy for relief of neuropathic pain from DPN and PHN. An investigation of the efficacy and safety of twice daily pregabalin enrolled 395 adults with painful DPN for ≥1 year in a 12‐week, double‐blind, placebo‐controlled trial. Patients were randomized to placebo, 150, 300, or 600mg/day pregabalin (n=96, 99, 99, and 101). Primary efficacy measure was change from baseline in endpoint mean pain score from patients’ daily pain diaries. Secondary efficacy measures included pain‐related sleep‐interference scores, Patient and Clinical Global Impressions of Change (PGIC, CGIC), and the EuroQOL Health Utilities Index (EQ‐5D). Statistically significant reduction in pain was observed in patients receiving pregabalin 600mg/day, and 46% of patients treated with 600mg/day pregabalin reported ≥50% improvement in mean pain scores from baseline (vs 30% of placebo patients, p=0.036). Number needed to treat to achieve such response was 6.3. Pregabalin 600mg/day was significantly superior to placebo in improving pain‐related sleep‐interference scores (p=0.003), PGIC (p=0.021), and CGIC (p=0.009). (Neither pregabalin 150 nor 300mg/day separated from placebo on these measures, largely because of an atypically large placebo response in one country representing 42% of patients.) All pregabalin dosages were superior to placebo in improving EQ‐5D utility scores (all p≥0.0263 vs placebo). Pregabalin was well tolerated at all dosages; adverse events were generally mild to moderate. Number needed to harm (discontinuation because of adverse events) was 10.3 for pregabalin 600mg/day.     

Efficient assessment of neuropathic pain drugs in patients with small fiber sensory neuropathies

We sought to develop an enrichment crossover study design that would allow us to efficiently evaluate and compare promising candidate neuropathic pain drugs. We evaluated the efficacy of gabapentin or tramadol vs. active placebo (diphenhydramine) in subjects with biopsy-proven painful idiopathic small fiber neuropathy (SFN) who were self-reported gabapentin responders. Eligible subjects entered two single blind run-in phases. In the first phase (Period A), subjects were treated with single blinded gabapentin at their prestudy dose followed by a second run-in phase (Period B) in which they were treated with diphenhydramine active placebo. Subjects with ?3 pain and a ?30% increase in pain intensity in Period B compared to Period A were then randomized to a double-blind three period cross over trial of gabapentin at pre study dosage, tramadol 50 mg QID and diphenhydramine 50 mg qhs. Of the 59 subjects enrolled, 41 subjects were excluded: Twenty-three had an insufficient rise in pain intensity in Period B; eight had skin biopsies that did not confirm SFN. Eighteen subjects were randomized into the double-blind, crossover phase. There was a significant treatment effect of gabapentin vs. diphenhydramine (p = 0.001) and tramadol vs. diphenhydramine (p = 0.018) by the before-bed daily pain score averaged over the final 7 days of each treatment period. We conclude that gabapentin and tramadol were effective in the treatment of painful SFN and that this experimental enrichment paradigm is attractive to screen potential neuropathic pain compounds for efficacy in proof-of-concept studies.     

A Randomized,Double-Blind,Placebo-Controlled Trial to Assess the Efficacy and Safety of Gabapentin Enacarbil in Subjects With Neuropathic Pain Associated With Postherpetic Neuralgia (PXN110748)

Gabapentin enacarbil (GEn) is an actively transported prodrug of gabapentin that provides sustained, dose-proportional exposure to gabapentin. This randomized, double-blind, parallel-group, placebo-controlled study evaluated the safety and efficacy of 3 different maintenance doses of oral GEn in subjects with postherpetic neuralgia. Adults with a 24-hour average pain intensity score of ≥4.0 received GEn 1,200 mg, 2,400 mg, 3,600 mg, or placebo for 14 weeks (including a 1-week up-titration, 12-week maintenance, and 1-week taper). The primary endpoint was change from baseline to end of maintenance treatment in mean 24-hour average pain intensity score. The intent-to-treat population consisted of 371 subjects (GEn 1,200 mg = 107, 2,400 mg = 82, 3,600 mg = 87, placebo = 95). With regard to the primary endpoint, all 3 GEn treatment groups demonstrated a statistically significant difference relative to placebo. The adjusted mean change from baseline for the treatment groups ranged from ?2.36 to ?2.72 versus ?1.66 for the placebo group. Exposure-response modeling suggested an ED50 around 1,200 mg/day, which was consistent with historical findings reported for gabapentin. The most commonly reported adverse events were dizziness and somnolence. All studied doses of GEn significantly improved pain associated with postherpetic neuralgia as compared to placebo and were well tolerated.PerspectiveGEn provides clinically important pain relief with doses from 1,200 mg to 3,600 mg and is generally well tolerated and efficacious. As an actively transported prodrug of gabapentin, it provides dose-proportional and extended exposure to gabapentin.     

A randomized,placebo-controlled trial of oxycodone and of gabapentin for acute pain in herpes zoster

Although acute pain in patients with herpes zoster can be severe and has a substantial impact on health-related quality of life, there have been no randomized clinical trials of oral medications specifically for its ongoing treatment. A randomized clinical trial was conducted in which 87 subjects ?50 years of age with herpes zoster within 6 calendar days of rash onset and with worst pain in the past 24 h ? 3 on a 0–10 rating scale initiated 7 days of treatment with famciclovir in combination with 28 days of treatment with either controlled-release (CR) oxycodone, gabapentin, or placebo. Subjects were evaluated for adverse effects of treatment, acute pain, and health-related quality of life. The results showed that CR-oxycodone and gabapentin were generally safe and were associated with adverse events that reflect well-known effects of these medications. Discontinuing participation in the trial, primarily associated with constipation, occurred more frequently in subjects randomized to CR-oxycodone (27.6%) compared with placebo (6.9%). Treatment with CR-oxycodone reduced the mean worst pain over days 1–8 (p = 0.01) and days 1–14 (p = 0.02) relative to placebo but not throughout the entire 28-day treatment period as pain resolved in most subjects. Gabapentin did not provide significantly greater pain relief than placebo, although the data for the first week were consistent with a modest benefit. By demonstrating that CR-oxycodone is safe, generally adequately tolerated, and appears to have efficacy for relieving acute pain, the results of this clinical trial provide a foundation for evidence-based treatment for acute pain in herpes zoster.     

Botulinum toxin type-A in the prophylactic treatment of medication-overuse headache: a multicenter,double-blind,randomized, placebo-controlled,parallel group study

Medication-overuse headache (MOH) represents a severely disabling condition, with a low response to prophylactic treatments. Recently, consistent evidences have emerged in favor of botulinum toxin type-A (onabotulinum toxin A) as prophylactic treatment in chronic migraine. In a 12-week double-blind, parallel group, placebo-controlled study, we tested the efficacy and safety of onabotulinum toxin A as prophylactic treatment for MOH. A total of 68 patients were randomized (1:1) to onabotulinum toxin A (n = 33) or placebo (n = 35) treatment and received 16 intramuscular injections. The primary efficacy end point was mean change from baseline in the frequency of headache days for the 28-day period ending with week 12. No significant differences between onabotulinum toxin A and placebo treatment were detected in the primary (headache days) end point (12.0 vs. 15.9; p = 0.81). A significant reduction was recorded in the secondary end point, mean acute pain drug consumption at 12 weeks in onabotulinum toxin A-treated patients when compared with those with placebo (12.1 vs. 18.0; p = 0.03). When we considered the subgroup of patients with pericranial muscle tenderness, we recorded a significant improvement in those treated with onabotulinum toxin A compared to placebo treated in both primary (headache days) and secondary end points (acute pain drug consumption, days with drug consumption), as well as in pain intensity and disability measures (HIT-6 and MIDAS) at 12 weeks. Onabotulinum toxin A was safe and well tolerated, with few treatment-related adverse events. Few subjects discontinued due to adverse events. Our data identified the presence of pericranial muscle tenderness as predictor of response to onabotulinum toxin A in patients with complicated form of migraine such as MOH, the presence of pericranial muscle tenderness and support it as prophylactic treatment in these patients.     

Efficacy,Safety, and Tolerability of Telcagepant in the Treatment of Acute Migraine: A meta‐Analysis

Although triptans are widely used for treating acute migraine, they are contraindicated or not effective in a large proportion of patients. Hence, alternative treatments are needed. Calcitonin gene–related peptide receptor antagonists, such as telcagepant, have been under investigation as a treatment for acute migraine. A meta‐analysis of the efficacy of telcagepant vs. placebo and triptans (zolmitriptan or rizatriptan) was performed. Randomized controlled trials were indentified from databases using the following search terms: migraine; calcitonin gene‐related peptide; calcitonin gene‐related peptide receptor antagonists; efficacy; safety, and telcagepant. The primary outcome measure was pain freedom 2 hours after first treatment. The secondary outcome measure was pain relief 2 hours after first treatment. Eight trials were included in the meta‐analysis (telcagepant = 4011 participants). The difference in pain freedom at 2 hours significantly favored telcagepant over placebo (odds ratio = 2.70, 95% confidence interval = 2.27–3.21, P < 0.001) and triptans over telcagepant (odds ratio = 0.68, 95% confidence interval = 0.56–0.83, P < 0.001). The difference in pain relief at 2 hours significantly favored telcagepant over placebo (odds ratio = 2.48, 95% confidence interval = 2.18–2.81, P < 0.001). The difference in pain relief at 2 hours did not significantly favor telcagepant over triptans or vice versa (odds ratio = 0.76, 95% confidence interval = 0.57–1.01, P = 0.061). These findings indicate that telcagepant can be effective for treating acute migraine. Calcitonin gene‐related peptide receptor antagonists represent a potentially important alternative means of treating acute migraine.     

Prolonged-release oxycodone enhances the effects of existing gabapentin therapy in painful diabetic neuropathy patients

Background: Neuropathic pain remains one of the most challenging pain syndromes; under‐diagnosed, poorly managed and associated with significant co‐morbidity. With standard therapeutic treatments, responders rarely exceed 50% pain relief and the majority suffer from residual pain. Titration to optimum dose is often limited by dose‐related adverse events. Aims: This randomized, double‐blind, placebo‐controlled study assessed the potential benefit of adding oxycodone (OxyContin® tablets) to gabapentin. The primary endpoint was to evaluate the analgesic efficacy of co‐administration of gabapentin and prolonged‐release oxycodone, whilst also evaluating the use of escape medication, sleep quality and global assessment of pain. Methods: Three hundred and thirty eight patients with moderate to severe painful diabetic neuropathy despite receiving their maximum tolerated dose of gabapentin, had oral prolonged‐release oxycodone or placebo tablets added to their therapy for up to 12weeks. Results: Oxycodone–gabapentin reduced pain score by 33% from baseline to end of treatment. The overall treatment effect was greater with oxycodone–gabapentin than with placebo–gabapentin (P=0.007). Oxycodone–gabapentin also significantly improved pain relief vs gabapentin alone (P=0.003). Oxycodone–gabapentin co‐administration was associated with less escape medication use (P=0.03) and fewer nights of disturbed sleep (P<0.05). Discontinuations due to lack of therapeutic effect were much lower (14% vs 54%) with oxycodone–gabapentin. The commonly seen opiate‐induced adverse events were not exacerbated by the combination of oxycodone and gabapentin. Conclusions: This study provides the first evidence that co‐administration of prolonged‐release oxycodone and existing gabapentin therapy has a clinically meaningful effect in painful diabetic neuropathy.     

Comparison of the Efficacy and Safety of Ketoprofen Plaster and Diclofenac Plaster for Osteoarthritis-Related Knee Pain: A Multicenter,Randomized, Active-Controlled,Open-Label,Parallel-Group,Phase III Clinical Trial

PurposeTo compare the efficacy and safety of ketoprofen plasters and diclofenac plasters after 3 weeks of administration in patients with osteoarthritis-related knee pain.MethodsThis multicenter, randomized, active-controlled, open-label, parallel-group, noninferiority phase III study randomized 236 adults with osteoarthritis-related knee pain for 3 weeks with ketoprofen plaster 30 mg twice daily (n = 118) or diclofenac plaster 15 mg once daily (n = 118). The primary efficacy end point was the mean change from baseline to week 3 in the mean knee pain intensity score during walking, as measured by a 100-mm visual analog scale with a predefined noninferiority margin of 10.0 mm. Secondary end points included changes in knee pain intensity score during walking (weeks 1 and 2) and at rest (weeks 1, 2, and 3), Knee Injury and Osteoarthritis Outcome Score, Patient Global Impression of Improvement scale assessments, and frequency of rescue medication use after 2 and 3 weeks of treatment.FindingsA total of 223 patients (115 in the ketoprofen group and 108 in the diclofenac group) were included in the per-protocol analysis. After 3 weeks of treatment, the least squares mean change from baseline in knee pain intensity scores during walking was −35.9 (95% CI, −39.7 to −32.2) in the ketoprofen group and −31.7 (95% CI, −35.5 to −27.9) in the diclofenac group, with noninferiority found (least squares mean difference, −4.2; 95% CI, −9.6 to 1.1). Ketoprofen significantly (P < 0.05) reduced the pain intensity score at rest after 2 and 3 weeks of treatment compared with diclofenac. No statistically significant difference was found between the groups in terms of changes in pain intensity score during walking at weeks 1, 2, and 3. The mean Patient Global Impression of Improvement score was statistically significant (P < 0.001) in favor of ketoprofen after 2 and 3 weeks of treatment. In addition, the Knee Injury and Osteoarthritis Outcome Score improved in both groups, and no statistically significant difference was found between the groups in terms of frequency of rescue medication use. The overall adverse event profile of the groups was similar, and no difference was found in skin reaction rates between the 2 groups.ImplicationsKetoprofen plasters can be effectively and safely administered to patients with osteoarthritis-related knee pain.     

Use of a lidocaine patch in the management of postsurgical neuropathic pain in patients with cancer: a phase III double-blind crossover study (N01CB)

Objective  Current therapies often have limited efficacy and untenable side effects when used to treat persistent incisional pain following cancer-related surgery. Lidocaine patches reduce neuropathic pain from herpes zoster but their benefits for persistent cancer-related postsurgical incisional pain remain unclear. Study design  Multicenter, double-blind, randomized, two-period crossover trial. Materials and methods  Twenty-eight cancer patients with postsurgical incisional pain were randomly assigned to receive either lidocaine patches followed by placebo patches or the reverse. Each study period lasted 4 weeks. Patches were applied daily upon waking and left in place for a maximum of 18 h. The primary outcome measure, an 11-point pain intensity rating scale, was administered weekly. Secondary outcomes were administered weekly (Brief Pain Inventory-Short Form(BPI-SF), Subject Global Impression of Change) and at the end of each study period (Short Form-Magill Pain Questionnaire, Linear Analogue Self Assessment Scale, Neuropathy Pain Scale, Pain Catastrophizing Scale, Profile of Mood States Short Form). Results  Twenty-one patients completed the first period and 18 completed their crossover second phase. No significant intergroup differences were detected in pain intensity ratings. Few secondary end points were significantly different when subjects used the lidocaine versus placebo patches. BPI-SF interference scores were lower in patients using the lidocaine patch during the first study period, including several scores that achieved statistical significance, general activity (p = 0.02), work (p = 0.04), and relations with others (p = 0.02). Conclusion  Lidocaine patch use did not significantly reduce pain intensity ratings or the majority of related secondary end points in cancer patients with persistent incisional pain. This study was conducted as a collaborative trial of the North Central Cancer Treatment Group and Mayo Clinic and was supported in part by Public Health Service grants CA-25224, CA-37404, CA-35103, CA-35119, CA-35415, and CA-35113. Additional participating institutions include: Medcenter One Health Systems, Bismarck, ND 58501, USA (Edward J. Wos, M.D.); Illinois Oncology Research Assn. CCOP, Peoria, IL 61615-7828, USA (John W. Kugler, M.D.); Abbott Northwestern Hospital, Minneapolis, MN 55407, USA (Daniel M. Anderson, M.D.); Siouxland Hematology–Oncology Associates, Sioux City, IA 51105, USA (Donald B. Wender, M.D.)     

A 14-week, Randomized, Double-Blinded, Placebo-Controlled Monotherapy Trial of Pregabalin in Patients With Fibromyalgia

The purpose of the study was to assess the efficacy and safety of pregabalin monotherapy in patients with fibromyalgia in a randomized, double-blinded, placebo-controlled trial. After 1 week of single-blinded administration of placebo, 750 patients meeting American College of Rheumatology criteria for fibromyalgia were randomly assigned to pregabalin (300 mg/d, 450 mg/d, 600 mg/d) or placebo, administered twice daily for 14 weeks. The primary outcome variable was comparison of end point mean pain scores, derived from daily diary ratings of pain intensity (0 to 10 scale), between each of the pregabalin groups and the placebo group. If positive, additional primary efficacy parameters included the Patient Global Impression of Change (PGIC) and the Fibromyalgia Impact Questionnaire (FIQ) total score. Compared with placebo-treated patients, mean changes in pain scores at the end point in pregabalin-treated patients were significantly greater (P < .001: 300 mg/d, −0.71; 450 mg/d, −0.98; 600 mg/d, −1.00). Compared with placebo, significantly more pregabalin-treated patients reported improvement on PGIC (P < .01 for all 3 pregabalin doses) and significant improvements in total FIQ score for the 450 mg/d (P = .004) and the 600 mg/d (P = .003) doses. Compared with placebo, all 3 doses of pregabalin were associated with significant improvement in sleep. The most commonly reported pregabalin-related adverse events were dizziness and somnolence, which tended to be dose-related.

Perspective

This randomized, placebo-controlled trial of 300, 450, and 600 mg/d of pregabalin monotherapy demonstrated that all 3 doses were efficacious for up to 14 weeks for the treatment of fibromyalgia and were well tolerated by most patients. These results provide evidence that pregabalin is an important treatment option for patients with fibromyalgia.     

A Pooled Analysis of Two Randomized,Double‐Blind,Placebo‐Controlled Trials of Milnacipran Monotherapy in the Treatment of Fibromyalgia

Milnacipran has been shown to significantly improve the pain, global well‐being, and physical function of fibromyalgia (FM), and is approved by the U.S. Food and Drug Administration for the management of this disorder. Post hoc analyses of data from two pivotal trials were conducted to further assess the clinical benefits of milnacipran, to determine the impact of baseline pain severity on treatment outcomes, and to confirm the safety and tolerability of this medication in patients with FM. Patients in these trials were randomized to placebo (n = 624), milnacipran 100 mg/day (n = 623), or milnacipran 200 mg/day (n = 837). Two different composite responder analyses were used to evaluate efficacy: a 2‐measure analysis, requiring ≥ 30% improvement from baseline visual analog scale 24‐hour recall pain scores and a Patient Global Impression of Change (PGIC) score of “very much improved” or “much improved”; and a 3‐measure analysis, requiring a ≥ 6‐point improvement from baseline in SF‐36 Physical Component Summary scores in addition to the pain and PGIC criteria. Additionally, a pooled analysis of mean changes from baseline pain scores was conducted in order to evaluate the efficacy of milnacipran over the entire course of treatment. At 3 months, composite responder rates were significantly higher in the milnacipran treatment groups than in the placebo group (2‐ and 3‐measure composite responder analyses: P ≤ 0.001, both doses vs. placebo). These improvements were not dependent on baseline pain severity. Similar composite responder results were observed in patients who continued treatment for up to 6 months. Significant improvements in mean pain scores were seen with both doses of milnacipran vs. placebo as early as 1 week after treatment initiation and were sustained for up to 6 months of milnacipran treatment. The most common adverse events associated with milnacipran were nausea, headache, and constipation.     

The effect of using vapocoolant spray for pain reduction in arteriovenous fistula cannulation among patients undergoing hemodialysis: A randomized control trial

AimThe aim of this study was to assess the effects of alkane vapocoolant spray in reducing pain during arteriovenous access cannulation in adult patients undergoing hemodialysis.BackgroundDeveloping and applying various approaches for pain relief remain important responsibility for nurses.MethodsThis study was designed as an experimental study with a cross-over design. Thirty-eight patients on hemodialysis volunteered to undergo cannulation of their arteriovenous access, after the application of vapocoolant or placebo spray or no intervention. Subjective and objective pain levels were assessed, along with various physiological parameters pre- and post-cannulation.ResultsStatistically significant between-group differences were observed in subjective pain at the venous (F = 4.97, p = 0.009) and arterial (F = 6.91, p = 0.001) puncture sites. The mean arterial site subjective pain scores were 4.45 ± 1.31 (no treatment), 4.04 ± 1.82 (placebo), and 2.98 ± 1.53 (vapocoolant spray). Significant between-group differences were observed in objective pain scores during arteriovenous fistula puncture (F = 5.13, p = 0.007). The mean objective pain scores after arteriovenous fistula puncture were 3.25 ± 2.66 (no treatment), 2.17 ± 1.76 (placebo), and 1.78 ± 1.66 (vapocoolant spray). Post-hoc test results indicated vapocoolant spray application was associated with significantly lower pain scores than no treatment or placebo. Patient blood pressure and heart rate recordings did not differ among the interventions.ConclusionVapocoolant application was significantly more effective than the placebo or no treatment in reducing the pain of cannulation in adult patients undergoing hemodialysis.     

A prospective,open‐label,multicentre study of pregabalin in the treatment of neuropathic pain in Latin America

Aims: The objective of this study was to evaluate the safety and efficacy of pregabalin at flexible doses of 150–600 mg/day in Latin American patients with neuropathic pain. Methods: A prospective, multicentre, open‐label, non‐comparative study included patients age ≥ 18 years diagnosed with neuropathic pain associated with diabetic peripheral neuropathy, postherpetic neuralgia, chemotherapy‐induced peripheral neuropathic pain (PNP), or human immunodeficiency virus‐related PNP. Eligible patients (N = 121) had a score of ≥ 40 mm on the visual analogue scale and a daily pain rating scale (DPRS) score of ≥ 4 throughout screening. Patients received flexible‐dose pregabalin (150–600 mg/day) for 12 weeks, which included a 4‐week dose‐adjustment phase. The primary efficacy measure was change from baseline to end of treatment/last observation carried forward (EOT/LOCF) in weekly mean pain score on the DPRS. Secondary efficacy measures included pain, anxiety, sleep interference, treatment satisfaction and Patient and Clinician Global Impression of Change. Results: Pregabalin significantly reduced the weekly mean pain score on DPRS from baseline to EOT/LOCF [–3.8 (95% CI: ?4.2 to ?3.3); p < 0.0001]. Reductions from baseline to EOT/LOCF were observed for all secondary efficacy outcomes (p < 0.0001). Pain and sleep interference were significantly improved compared with baseline across all weeks of the study, as early as 1 week after initiation of pregabalin (p < 0.0001). The most common adverse events (AEs) were somnolence, dizziness, weight gain and peripheral oedema. Nine (7.4%) patients discontinued the study because of AEs and 25 (20.7%) temporarily stopped or reduced their pregabalin dose because of AEs. Conclusions: Flexible‐dose pregabalin (150–600 mg/day) significantly reduced pain and anxiety and improved sleep and was generally well tolerated in Latin American patients with neuropathic pain.     

Daily repetitive transcranial magnetic stimulation of primary motor cortex for neuropathic pain: A randomized,multicenter, double-blind,crossover, sham-controlled trial

There is little evidence for multisession repetitive transcranial magnetic stimulation (rTMS) on pain relief in patients with neuropathic pain (NP), although single-session rTMS was suggested to provide transient pain relief in NP patients. We aimed to assess the efficacy and safety of 10 daily rTMS in NP patients. We conducted a randomized, double-blind, sham-controlled, crossover study at 7 centers. Seventy NP patients were randomly assigned to 2 groups. A series of 10 daily 5-Hz rTMS (500 pulses/session) of primary motor cortex (M1) or sham stimulation was applied to each patient with a follow-up of 17 days. The primary outcome was short-term pain relief assessed using a visual analogue scale (VAS). The secondary outcomes were short-term change in the short form of the McGill pain questionnaire (SF-MPQ), cumulative changes in the following scores (VAS, SF-MPQ, the Patient Global Impression of Change scale [PGIC], and the Beck Depression Inventory [BDI]), and the incidence of adverse events. Analysis was by intention to treat. This trial is registered with the University hospital Medical Information Network Clinical Trials Registry. Sixty-four NP patients were included in the intention-to-treat analysis. The real rTMS, compared with the sham, showed significant short-term improvements in VAS and SF-MPQ scores without a carry-over effect. PGIC scores were significantly better in real rTMS compared with sham during the period with daily rTMS. There were no significant cumulative improvements in VAS, SF-MPQ, and BDI. No serious adverse events were observed. Our findings demonstrate that daily high-frequency rTMS of M1 is tolerable and transiently provides modest pain relief in NP patients.     

Efficacy of frovatriptan in the acute treatment of menstrually related migraine: analysis of a double-blind,randomized, cross-over,multicenter, Italian,comparative study versus rizatriptan

The objectives of this study are to assess the efficacy and safety of frovatriptan, and rizatriptan in the subgroup of women with menstrually related migraine of a multicenter, randomized, double blind, cross-over study. Each patient received frovatriptan 2.5 mg or rizatriptan 10 mg in a randomized sequence: after treating 3 episodes of migraine in not more than 3 months with the first treatment, the patient had to switch to the other treatment. Menstrually related migraine was defined according to the criteria listed in the Appendix of the last IHS Classification of Headache disorders. 99 out of the 125 patients included in the intention-to-treat analysis of the main study were of a female gender: 93 had regular menstrual cycles and were, thus, included in this analysis. A total of 49 attacks classified as menstrually related migraine were treated with frovatriptan and 59 with rizatriptan. Rate of pain relief at 2 h was 58% for frovatriptan and 64% for rizatriptan (p = NS), while rate of pain free at 2 h was 31 and 34% (p = NS), respectively. At 24 h, 67 and 81% of frovatriptan-treated, and 61 and 74% of rizatriptan-treated patients were pain free and had pain relief, respectively (p = NS). Recurrence at 24 h was significantly (p < 0.01) lower with frovatriptan (10 vs. 32% rizatriptan). Frovatriptan was as effective as rizatriptan in the immediate treatment of menstrually related migraine attacks while showing a favorable sustained effect with a lower rate of migraine recurrence. These results need to be confirmed by randomized, double-blind, prospective, large clinical trials.     

Two doses of botulinum toxin type A for the treatment of trigeminal neuralgia: observation of therapeutic effect from a randomized,double-blind,placebo-controlled trial

Background

In the majority of cases, trigeminal neuralgia (TN) is a unilateral condition with ultra-short stabbing pain located along one or more branches of the trigeminal nerve. Although prophylactic pharmacological treatment is first choise, considering of insufficient effect or unacceptable side effects, neurosurgical treatment or lesion treatment should be considered. In addition to all these procedures mentioned above, one approach has been based on local intradermal and/or submucosal injections of Botulinum Toxin Type A (BTX-A).

Methods

We conducted a randomized, double-blind, placebo-controlled since November 2012, and adopted local multi-point injection in 84 cases of classical TN with different doses of BTX-A. Eighty four patients were randomized into following groups: placebo (n = 28); BTX-A 25U (n = 27); BTX-A 75U (n = 29). Follow-up visits were conducted every week after the injection, and the overall duration of the study for each patient were 8 weeks to observe the pain severity, efficacy and adverse reactions at endpoint.

Results

The visual analogue scale (VAS) scores of 25U and 75U groups reduced significantly compared to placebo as early as week 1, and sustained until week 8 throughout the study. There was no significant difference in VAS between 25U and 75U groups throughout the study. The response rates of 25U group (70.4%) and 75U group (86.2%) were significantly higher than placebo group (32.1%) at week 8, and there was no significant difference between 25U and 75U groups. Evaluation of the Patient Global Impression of Change (PGIC) demonstrated that 66.7% (25U group) and 75.9% (75U group) of the patients reported that their pain symptoms were ‘much improved’ or ‘very much improved’ versus 32.1% of the placebo group, and there was also no significant difference between 25U and 75U groups. All adverse reactions were graded as mild or moderate.

Conclusions

BTX-A injection in TN is safe and efficient. It is a useful treatment for refractory TN. Lower dose (25U) and high dose (75U) were similar in efficacy in short-term.     

Duloxetine 60 mg/day for the prevention of depressive recurrences: post hoc analyses from a recurrence prevention study

Objective: To assess the efficacy of duloxetine 60 mg/day in the prevention of depressive recurrence in patients with major depressive disorder (MDD). Methods: Patients having at least three episodes of MDD in the past 5 years received open‐label (OL) duloxetine 60–120 mg/day for up to 34 weeks. Patients meeting response criteria were then randomised to either duloxetine or placebo for up to 52 weeks of double‐blind maintenance treatment. Only patients taking duloxetine 60 mg/day during the OL phase, and randomised to either duloxetine (remained on 60 mg/day dose) or placebo, were included in this post hoc analysis. The primary outcome measure was time to recurrence of a major depressive episode. The 17‐item Hamilton Rating Scale for Depression (HAMD₁₇) was used to evaluate depressive symptomatology. Global and physical functioning and pain were also assessed. Safety and tolerability were assessed via analysis of treatment‐emergent adverse events (TEAEs), vital signs and weight. Results: A total of 124 patients were randomised to duloxetine 60 mg/day (n = 64) or placebo (n = 60). Time to depressive recurrence was significantly longer in duloxetine‐treated patients compared with placebo‐treated patients (p = 0.001). During the double‐blind maintenance phase, 31.7% of placebo‐treated patients experienced a depressive recurrence compared with 12.5% of duloxetine‐treated patients (p = 0.004). The HAMD₁₇ total score and most of its subscales as well as the Clinical Global Impression of Severity (CGI‐S), significantly worsened in the placebo group compared with the duloxetine 60 mg/day group. There were no significant differences between treatment groups in TEAEs, discontinuations because of adverse events, vital signs or weight. Conclusions: Treatment with duloxetine 60 mg/day was associated with a longer time to depressive recurrence and a significantly lower recurrence rate compared with placebo.